PLEASE NOTE: This information is intended for EV owners who only drive a short distance each day and then plug in each night. The data presented only applies to ternary type lithium batteries (e.g. NMC), not Lithium Iron Phosphate (LFPO). If that isn't your situation then don't waste your time watching or posting irrelevant comments. Also note that a "DST Cycle" referred to in the Battery University study means one discharge and recharge to the levels specified in the test (e.g 75% - 65% SOC). However the industry term "cycle", when used to predict battery life, means one transition from fully charged to fully discharged and back to fully charged. So there would be 10 X 75% - 65% events before one charge "cycle" is clocked against the battery's lifetime cycle count. While the science may seem complex the key message is simple: - You don't need to change your lifestyle or stress about your battery - You can keep driving as you do currently and plugging in each night so your car is always ready at the start of the day - If you simply lower the maximum State of Charge (SOC) from 90% to something more appropriate, like 60% this can enhance the longevity of your battery. This is because the battery spends less time standing with a high SOC. Lastly, I am not telling anyone what they should do, just presenting the science. In the end it's your car and your choice how you charge your EV. Have a great day ! 🙂
@@rambleon1182 yeah don’t worry about the car only lasting a few years because the battery is naffed. We’ll just get a new one anyway, and tech is changing that quickly that you’ll want the new tech anyway.
@@jlrguy2702 Exactly they are not cars just mobile tech platforms with a very short real life buy a new ev now and in 2 months it will have lost 50%of its cost price just get a good old V8 muscle car and enjoy your drive
You should revoke the video or at least the commentary, because the advice you give is leading to increased battery degradation. As others point out, the light blue line would result in the maximum extracted charge before reaching 90% soh.
I think the math is a little off here. Since let's say your commute is the 10% you're talking about. If you would do the 100-25% charge, you can drive for 7,5 days before charging (so 7,5*1000/365=20 years), while with the orange line you need to charge daily. So if you look at it that way the light blue and pink are the best modes 5*3000/365=40 years or 3*5000 which is the same. 40 years seems very unrealistic to me, since you will have so degradation over time itself (storage). So all in all I don't think the factory 80-25 is all that bad. Maybe 75-25 or 75-40 might be bit better. I now charged up to 80% so I think I'll set it to 75 instead. My commute takes a bit more of the batter though, about 15%.
I agree, you need to convert the number of cycle and DoD into KWh and then you can see which strategy have most battery life (in term of power discharge until battery degrade to 90%) From the last chart I think the 25-75 charging strategy @ 3000 cycle will output most energy before reaching 90% battery degradation.. putting that number for my ionic 5, that translate to around 108,000kwh power discharge and @ 5km / kWh (low estimate), the battery will last 540k km. At 25k km per year that is 21 years of driving... So that means after 20 years I will still have 90% battery capacity. But I live in tropical country and the normal temperature here is around 33°c and sometime I charge to 100%. so maybe 10 years is more accurate estimation.
@@lampe36there is no true understanding of cycles except for general term of cycle meaning the returning of a state. So short cycle is a cycle that is not equal to a long cycle which is also a cycle. A cycle is a cycle but not all cycles are the same. Measuring longevity in cycles is a terrible unit to use in most cases when cycles are not the same cycle. It’s like comparing the price of things in pennies but some things are in Australian pennies, some in Euro pennies, some in American pennies, and etc.
So I agree on both the math being odd, and radically unequal “cycles”… however, given I usually drive < 20 miles, it will have zero impact on my life if normal daily charging is to 75%.
@@BrianThorstadyes it’s pretty much the same thing I said about my civic when I was offered a regular oil change versus a synthetic oil change. Is it really going to make a difference?
I own my model P85 for 10 years already. Not a sign of battery degradation because I never charge above 80 %. When I don't use my car for a while it stays on 50%. Then when I am going for a trip I charge the power I need for this particulary trip. Sometimes I supercharge up to 80% to heat the battery to get a temperature to remove condensation and water out of the battery pack. Corrosion in the electronics also damages it. Still super satisfied with my Tesla after 100.000 miles.
Did ever any cell failed as it happens to ebikes all the time? One cell goes out and you have to buy a new battery, for it's too expensive to fix it. I wonder what happens in a car. Do they separate like packages of 6 or 12, and the system just jumping over them? Maybe they can be replaced? Can you enlighten me, please?
It is possible to repair a car's battery, it is better to treat the battery discribed in this video. Cars have a smart battery management system (BMS) , this holds the battery healthy.
Your battery may seem fine but you should have it serviced at a non Tesla shop anyway. Replace the butterfly valves and reseal the battery. After 10 years the valves will be filled with dust particles and will let moisture get inside.
I do not see why I should let someone take "care" of my cars battery, only to let them earn some money ? Have no fear for dangers that never appear , thats how my generation avoids unnecessary stress. I sometimes charge on a supercharher and let the fans cool my bettery , I do not drive in streets with 10 cm's of water and I don't drive in winter when salt is on the street, then the car stays in the garage and I use my Mercedes E type T modell. I balance my battery every year once and see how long it lasts. Do I need a new battery pack in the future ? So what ? I paid my model S P 85 cash in 2014 and I can pay a new battery pack without any problem. That's the comfort of saving money instead of going on vacation 3 or 4 times a year. Our second home in Germany gives us all we want.
You may not notice any signs of battery degradation, but they still degrade naturally due to time. You also have to take into consideration things like temperature, depth of discharge and cycling. Not charging above 80% definitely helps to prolong battery life, but there are additional steps you can take beyond just the basics in order to maximize your battery's lifespan.
In our training from GM for the Bolt EUV we have been told to recommend to customers that they use the moto ABC: Always-Be-Charging. Their explanation was that the car will manage the battery temperature while the car is parked. One fellow on TH-cam has a short video showing his Bolt expelling excess heat during a very hot day. His car wasn't running, just plugged in. So while not charging everyday may be a good idea that would be only when the outside temperature is neither too hot or too cold. At least where GMs are concerned. Charging to a lower level most of the time seems to be a good idea that most agree on. My cell phone has a battery management setting that you can switch on and it limits the charge to 85%. This is meant to increase battery life (Samsung phone). I drive a Bolt EUV and have set my maximum charge at 80%. I may lower that to 75%. I also use slow charging as it seems to be recommended by most. Thanks for the video. I found it most useful. In addition, the comments left by some viewers also contributed to my battery education.
Thanks for adding to the conversation Phil. You make some good points here. I think your suggestion is probably the best approach. Plug the car in each day but set the maximum SOC to the minimum you will require to complete your daily commute. In my case I only travel 14kms (7 miles) each day so I can get by with charging to just 60% and only increase this if I'm planning a long trip out of town.
The reason GM likely instructs people to always charge their car, is because it reduces range anxiety, performance is at its peak, you'll likely never get stranded with a dead car, all of which reflect poorly on the car/EVs. Manufacturers dont care if 7 year old cars have decreased battery health, they already profited, and arguably degrading battery health means consumers buy more cars. What is best for manufacturers isnt always best for consumers.
I have a Bolt EUV and follow the ABC mantra. However, I set my max charge level to 80% on the Charging settings so its never fully charged. Only when we go on roadtrips do I take that setting off.
the reason why is because the bolt is more willing to use the battery heater or cooling system when plugged in but when not plugged in, it doesn't want to drain battery so let the battery heat up.
I was charging to 80% and then only charging when less than 50%. Since, on my daily commute, I always came in right at about 50%, I am going to only charge up to 70% and see how it goes. I am also intrigued by potentially charging at a lower rate too. I can recharge in two hours, but I have 8 hours to do it in over night so am giving that a try too. Thanks for the food for thought.
A lithium-ion battery is happy between 25% and 80% SOC. However the BMS needs to know the extremes as well so do go to them occasionally. It is okay to charge to 100% but it is bad not to use this first 10-20% shortly after: like if a battery being under stress while fully charged: the shorter we leave it in that condition, the better. So please just charge to 100% the night before occasional long distance trips.
That's why I am glad to see the data, otherwise we only have stuff like "battery is happy" to base decisions on. Batteries are incapable of being happy.
My usage varies from 20 to 110 miles each day. I charge my 2021 Ford Mach E at home to 90% daily as recommended in the owners manual. With over 60,000 miles on the odometer I don’t see much degradation. Charging to 90% still shows 238 miles of range
@@AlexLplusbattery is happiest at 50%, so 35-65% would be much better than 20-50%. That's too low to go if you are trying to extend battery life to the max.
The magenta (75%-45%) most closely represents my usage cycle and I charge twice a week which = 43 years (I'll be 106 years old) btw - the warranty is 80% and I had a starting capacity of 331 miles so at 90% I still have 300 miles of range & (80% = 270 miles) which is still quite usable
@didyuknow more like stick with an ice vehical. ev owners have to be insane. dont use the heater, use blankets and the seat warms. what kind of ghetto cars are these.
Most battery capacity is loss just from yearly losses without even using the battery He showed a chart on this, so you will lose about 2-4% of capacity a year just by not using your battery.
Been basing my model 3 LR off the 75%-25% line, and the battery is doing well, the car is at about 110,000 miles in 4 years. Just plug it in every night, and every morning it's at 75%, much less than is needed for a typical day.
This is good advice. Keeping the EV battery balanced is the best for longevity. I got a 14 year old Prius and can monitor the battery charge level. Toyota seems to keep the battery between 45 and 60% charged. It is still running well on the original battery.
Thank you for this information. Very useful. I’m now trying to keep my SOC between 40%-60%….so re-charge when the SOC is close to 40%. This works for me as i tend to drive less than 20 miles each day. It make sense that the battery is “happiest” around 50% SOC. I’m also avoiding fast chargers when possible.
I put over 250,000 miles on 4 plug-in hybrids over the last 10 years. They had a built-in battery buffer of 20%, so that "100%" charged/full was actually only charging up 80% of the battery. The result was that none of the PHEVs showed ANY visible loss of range during the time that I had them. Granted, because 20% of the battery capacity was not shown to the driver, they could have lost up to 20% of their capacity without it being seen. But they also could have actually lost minimal battery capacity over the years of daily driving and charging (L2) use.
It lasted that long because the majority of those 250,000miles where driven with an ICE engine. If someone uses the electric part of their hybrid a lot, the battery cannot last that long, because the battery will go through charge cycles like crazy. If a hybrid does 30miles on it's battery for daily driving and someone would actually do those 30miles every day on the battery, they would have accumulated more than 1000 full cycles in less than 3 years.
You omitted the fact that part of this 'precautions' are already done by the BMS auromatically. If you charge to 100%, this is not really 100%, as the battery physically has 8% or so more capacity, which is 'fenced off' by programming in the BMS. Similar at the low end...
@@authorified89 why not? my battery is gross 35,5kwh, im only allowed to charge it to 30 kwh, if I charge it to 90%, that will be 27 kwh, and it would be 76% charged. My soh Im assuming is worked out from how many kwh i can get from the votlage that gave me 30 kwh when car was new.
@@bjorn2fly oh I misunderstood then, 75% of 35 kWh is significantly different from 30kWh indeed. Its good to keep in mind the actual battery percentage instead of what the car shows, my bad
Tesla have about 4kWh bottom lock on larger packs. I.e. when a 100kWh battery shows 0% it's true percentage is 4%. You can't use this 4kWh. There is also top lock but I don't know the figure. @cigersuz
Excellent points, Mark.....thanks for doing the hard work to investigate the subject. I would add though that it is important to prriodically charge to 100% SOC, in order for the battery management system in most cars to perform cell balancing. Perhaps adopting a routine that the first day of each month, you charge to 100% using level 1 or 2 charge point, and return to your regular routine for the rest of the month, would preserve battery maintenance and maximize service life. Thanks again for doing this.
TH-camr bjorn said that after charging to %100, you need to discharge all the way to 0-5% at one go to calibrate bms system. Not just charging to %100 and then discharging in a week or so.
I'd save that 100% charge for when you are doing a long trip, timed to end just before you set off, and run it down to 10% to help balancing. No need for once a month, they take 6 months to get out of balance in my experience (Tesla S since 2016). My old S still held 95% original capacity after 87,000 miles.
A significant variable to degradation is also depth of discharge (DOD). Avoiding large depth of discharge prevents expansion and contraction of the electrodes which leads to cracking. A DOD 10% to 20% has a little impact on battery degradation above 20% has increasing impact. 20% of discharge provides very little degradation above 10%, but provides twice the mileage driven. Therefore the ideal charging range is in fact 40 to 60%, pushing this to 30 to 70% may be ideal for most peoples practical usage with the additional small degradation being worth the increased usability.
Great video. Thank you so much for your work on this. Leaving a comment to show my appreciation, and also to express that for a very technical subject, this video gives a perfect explanation and context of how to optimize your EV's battery life. Cheer my friend. Thanks again!
We just traded our 12 year old Prius C for a 2024 Prime. The Prime is our third hybrid but first PHEV. The C had 128,000Km on "the clock" and from the beginning gave between 4 & 5 l per 100Km (dependant on ambient temperature). Regards charging cycles; its battery was just under 1kw, so, it was constantly being charged and discharged every time it was driven. At about ten years, the battery would no longer gather enough charge to run the car in EV Mode (which even when new, was limited to 1~2Km's. But, even with that constant charge/discharge rate, the litre's per 100Km performance did not decline. The new Prime's Traction Battery is close to 13 times the "size" of the C's. It incorporates a charge "buffer" of (I think), 10% lower and upper, meaning there's 80% of usable charge. Yesterday, I drove the Prime 88Km in EV Mode and the Trip Computer indicated there was 6% charge left. The car would have exceeded 90Km on battery. This morning, the computer stated the range would be 91Km. For us, the Prime is essentially a BEV. After 5,000Km we have used just 1.5 tanks of fuel. Based on the length of service the C's battery gave, we have no concerns about the level of charge/discharge with the Prime. The Traction battery has a ten year warranty, we plug-in every night and don't worry about cycles.
Spot on! We LOVE having plenty of fuel in the tank with an ICE car. We also LOVE having plenty of charge in the battery for an EV, but for the majority of us that’s complete overkill. HOWEVER keeping the max charge below 65% to 70% is always going to be much better for the battery …. and even more so in hot climates. If you must fill it, don’t leave it there for long, drive immediately. If you arrive home near empty, charge it to at least 20% immediately.
Interesting my BYD has a 60KWhr LiFePO blade battery configured 126S1P. The recommendation is to charge it to 100% once per week. Our daily driving during the week uses about 60%. Consequently we slow charge it (AC3KW) each Sunday (mainly using solar panels) to 100%. We only fast charge on trips, typically at the 50KW rate. Under fast charging, charging efficiency and rates decrease markedly over 85%, with a good deal of energy lost as heat. So when fast charging we normally stop at 80-90%, particularly if the weather is warm. The BMS rolls the fast charge back anyway over 90%. On trips we mainly operate between 15% and 90% for an effective range of 300km between top ups. On routes we mostly drive, this works well. So far we have not detected any battery degradation.
Really interesting... thanks for your research and clear summary. My charging routine was to use the 80-20% range but after this, i’m going to follow your recommandation. Apart of course when i’m doing à road trip. Then i slowly charge to 100% during the night befor departure, and using my obd connector, capture the capacity of the battery so that i can follow up battery degradation. ( i have a mustang mach e with edtended battery)
This is good information. I drive my Ioniq 5 about 40 km daily and charge level 2 free at work several times weekly. I think it is reasonable to lower my end charging a bit, dropping from 80% to 70% with a goal to keep the battery between 40-70% state of charge. My understanding is that the Ioniq 5 needs to be above 40% state of charge to recharge the 12 volt battery. Thanks for posting this.
Very valuable information. I have owned a model Y for almost 3 years and have been reviewing charging advice videos. This is the best one I’ve seen by far. Thank you.
@frankpainter7571 Be aware that your Tesla model Y uses a lithium phosphate battery, so has different recharge characteristics than those covered in this video.
Were we live and work, lots of people travel over 100 miles per day. So my Leaf, uses 75 to 80% per day. Current at 48000 miles. And the car came with extra warranty on the battery.
Thank you. It kind of fits what I knew about batteries (storage % voltage for batteries waiting to be shipped and sold by battery companies is 65%). Until now I was charging my car at 80% every day (Model Y 2023, Long Range). Now, I will charge my car to 60%, use 3% to get to work, it will stay on parking at work and lose 2% more during the day (sentry mode usage-security), then lose another 3% on its way back, then it will be at 52% and stay that way until the charging start 3 hours later. Friday, I will charge to 80% in case of a longer driving during the weekend.
@@sybaseguru Nope, not in my case. I can't trickle charge more than 17% in a night . And the charging automation of the car work per day so I do not want to manually modify the charging of the car via the app every other day. I have peace of mind the way I am doing it at the moment.
Because most people use less than half the battery pack’s capacity each day, a new Swedish study charged cars up to 50%, and then charged them back up to 50% after use. They got spectacular improvements to battery pack service life vs. charging it to any other amount.
I know my iPhone batteries have a lifespan more than double the length of everyone else in my home. And usually longer runtime each charge. Everyone else plugs their phone in overnight daily so it’s “fully charged” each day. I never plug in until after I get the 20% warning and whenever I am able, try to unplug between 80-90%. The info in this video seems to concur.
Ternary Lithium Batteries (NCM and NCA) should normally be operated around the 50% capacity level. An example of this is when your daily round trip only requires you to charge the battery up to 60% when you leave home, and the battery drops to 40% when you return. So the battery is only cycling around the 50% of full capacity. If you keep doing this regularly, then your battery degradation will be practically immeasurable for a very long time.
All wonderful theory. But.. a vehicles BMS handles a lot of this. Cars are now coming with 7 year unlimited km warranties, incl battery, so this might suggest the manufacturer has thought about what end users may or may not do. Limiting yourself so religiously to using such a small % of a battery is very counter to the whole driving experience and can become an obsession. There are so many variables indicated that affect battery longevity that you zero control over. Here in Australia, days and weeks go by where temps well exceed these "lab tests," and I would guess the same is true in European winter based climates where it goes below zero. The alternative to all of this science and maths, etc, is to enjoy the car you drive in the climate conditions that prevail for you and use common sense and manufacturers recommendations given they cover your warranty 😀
People want to keep these cars for way longer than 7 years, hence the video. Manufacturers care little about after warranty. It's like when they say only change the oil every 20,000 miles. They want the car to die after warranty expires. Although Tesla battery packs are lasting 420,000 miles from 2017 cars and growing. Refurb packs I wouldn't trust from earlier cars.
The question should be how much will the cost of the battery will be 5-10 years from now to replace. Might only cost a few thousands to replace a battery at the rate of how fast the cost is dropping. Also, by then there will be more fast charger available like gas stations. So do u want to pay a little extra for less inconvenience?
Very interesting, I have set mine for daily drive to 65% charge and discharge will land around 40% as I use about 25% on my daily commute. No degradation yet after 3.5k miles.
Thanks for this interesting video. My Megane e-Tech EV60 is always charged at 80% and when the percentage is down to 60,50 or 40%, I charge at home with 7 kWh (32A). After one year, Renault told me the battery is of 98% capacity. Now, after hearing what you told, I’ll switch fom 80 to 75%.
Time at max or min charge, is equally important as the charge level. In other words, don't leave your battery charged at a higher charge level or a lower charge level for a long period of time.
I use about 25-30% battery on my 132km daily commute. I now charge to 60% and arrive back home with 30-32% remaining. I’ve noticed a phantom discharge always occurs in the hours after arriving at my work when the SOC at the time I park is in the 59% to 69% range. I generally loose 3-5% SOC level while parked at work 8 hours. My daily commute is 132km RT. I’ve adjusted my daily charging so when i arrive at work, my battery is less than 55%. My main emphasis is always avoid parking for any amount of time with a battery level above 58%. I find i consistently gain a few percent battery if i arrive at work with 50% or less.
When these tests were performed were they using an actual car and the cars BMS, or were they just testing battery packs or even just cells in a lab setting? Seems the the manufacturers BMS would have a pretty large influence on the batteries and their lifespans, regardless of how much or how little you were charging. EDIT: Just looked at the article - they were testing batteries for handheld devices, not batteries for automotive use. Not sure these guidlines can be carried over directly.
The basic principles about battery chemistry and how it behaves still apply. The same tests have been made with all kinds of cell formats and the results show obvious tendencies.
You need to normalize the data for amount of battery used. For instance the 75-25 cycle gets you 5x the driving distance of 75-65 yet it lasts more than 1/5 of the cycles. So based on this chart a 75-25 cycle seems to be the best option. Just don’t charge it every day. I’d take a look at you median daily drive and make sure that you battery covers probably 3-4 times that distance at minimum. Then plug it in only when you get to 25% and then charge to 70 or 75%. There is also time degradation which is why you don’t want an overly massive pack unless you do frequent long trips. Basically the first gen electrics with 100miles or so range are probably the sweet spot for most people.
@marksjustimagine I understand and agree with the logic of not charging to 100% or discharging to near zero, however, one major flaw in the approach is that charging more regularly (daily) from 35 % to 75% SOC (40% for say 160 km) would require twice as many charging sessions as one charging cycle from 10% to 90% (80% for 320 km)
Number of charging sessions doesn't matter much. It's the total number of charge cycles. One cycle being from 0% to 100%. So topping up by 10% each time, would take 10 sessions to complete one charge cycle of 100%.
Great video. I feel you nailed in your sum up and what you are personally doing with the 40 - 60% cycle, a pity that study didn't include that or even 45 - 55%. I think this rule of thumb would also be great for someone who can only charge by fast charger, if they are also an urban dweller whose commute is short, then they could do this just once or twice a week for probably only ten minutes a time and end up way better off than those who fast charge huge depth all the time. Also I'd be very interested to see the results if it was dialled back even more to say 20 - 40%, the battery is charging very quickly at this stage because it is under virtually no stress. Could be even better than that mid range. Just an amateur thinking out loud here :)
Graph at 12:00 : it appears that Yellow is better than purple - but its not. The purple covers a 30% cycle min/max- 3 times more power than the yellow (10% cycle min-max), so I need only charge up a third of the number of times. In fact purple has half the number of cycles at 90% capacity retention, so is providing 50% more mileage. Purple looks optimum on this basis so one should aim for keeping charge in the 45% to 75% range, but dropping to 25% is not a disaster as the blue line shows only a minor degradation hit.
Really good. Thanks. This one is well researched -- and there isn't any hidden agendas. There is so much bad information out there. My Tesla S has 216,000 kms -- and I've lost about 10% of capacity. I've tried to stay between 20%-80% SOC but I do many road trips so 50% of my charging has been on superchargers.
own a BMW after its out of lease and Warrantee ? get ready for 2K a year minimum for the next 10 years of ownership and many tows.... at least Tesla's servicing and maintenance over the life of the car are far less than ICE engines.@@JetFire9
@@JetFire9 From where do you know how big the battery is in OP's Tesla and how long it's going to last? 🤔 Can you tell me when I need to replace the battery for my 2015 DeWalt drill and how much a new battery costs? Thank you 😊
Very helpful. I think that everybody can get its own lessons. I lowered my limit from 80% to 75% which would mean that my car would sit most of the day in the 55-65% SOC range. I also delayed my scheduled charge in the am so that I drive it only about half an hour from reaching 75%. This seems to fit my driving pattern the best and hope I will be a happy owner for a long time (MY LR).
Thank you for doing the research/hard work for me. This has helped me greatly. We have a 2023 LR Model Y and use just under 40% total charge each workday. We have been following the recommended 80% charge each night, only going above for long trips. I will now change our daily habits to ‘bracket 50’. 70% max overnight…car will rest at work at @50% during day, having us just over 30% when we get home. This seems to be the closest scenario to the purple/orange line on the ‘stress test’ table for us. Again, awesome work and many thanks for your research.
PERFECT, bracketing 50% is perfect and mimics what all, all, all Li-ion battery manufacturers say to hibernate your battery, as at 50% you stress it least and protect against depth of cycle.
If battery is preconditioned it does not damage from fast charging. There are charts online that compare battery degradation of Teslas that are often supercharged and others that are rarely supercharged. The degradation is almost identical.
There are two ways to measure cycle life. One, is to count the number of times the car is driven, and the number of times it is plugged in to recharge. The other way, is to measure throughput. That is the total number of amp hours the battery puts out over its lifetime, divided by its rated amp-hour capacity. (sometimes referred to as "equivalent cycles") I do believe this would be the most relevant, because that translates to the total miles the battery lasts in an electric vehicle, before it needs to be replaced. In many cases, the best margins would be between 30% to 70% states of charge. Most manufacturers recommend 30 to 80%, to use the middle 50% of total capacity on a day-to-day basis. Occasional charges to 100% aren't too detrimental, as long as the car is driven immediately after the full charge, and is done only on the occasional long trip where you really need all the capacity the battery has to offer. You don't want to charge to 100%, then leave it at that state of charge for a full day. I was looking at the cycle life graph of a Trojan golf cart battery, (liquid filled deep cycle lead acid)and calculated the total equivalent cycles, and it didn't make any difference whether the battery was discharged 80% down to a 20% state of charge, or, if it was drawn down 20% to an 80% state of charge. The total ampere hours available over its lifespan was the same! (keep in mind, Lead Acid batteries REQUIRE charging to 100%, to avoid sulfation)
Thanks Vincent for your contribution to this discussion. Indeed it is the second way that most manufacturers use when publishing battery warranty. The key take away from the Battery University study is that, as you suggest, the worst thing you can do is charge to 90+% and then leave the car standing for a day, or even overnight.
I see lots on this topic about batteries for full EVs though very little for a PHEV which what I happen to have (Mazda CX-90 PHEV 17.8-kWh lithium-ion battery). I am finding I my daily driving is in the 40km to 60km range, occasionally farther which is when the gasoline engine comes in handy but I did buy it with the idea that the majority of my driving would be in EV mode. My car has only about a 40km electric range and trying to keep it in the 20% to 80% range generally recommended for batteries means the usable electric range would be reduced to only 24km which is not much at all. I understand that for a PHEV the battery never really gets to 0% no matter what the gauge on the dash shows but I don't know what it actually does go down to. When I questioned my dealer they said charging the battery to 90% daily is fine (at home not fast charge) and I don't worry about how low it goes, I let the car's software deal with that. If I am away for a month or more, which does happen from time to time, I store it with about a 50% charge. I've only had the car for a year so it's hard to tell if I am doing the right thing or not. I've no idea what will happen long term and no one seems to be able to tell me.
Most EV owners fixate on charge levels, but do not consider a major portion of degradation is due to time, not much you can do about that, except to keep the car away from high temps.
They fixate on charge levels because that’s about all they can control. Time/age is not controllable so of course they discount it. And keeping it away from higher temps has no impact on time/age.
I guess the least I can do is share my experience. I own a 2021 MG ZS EV with a 44.5 kwh NMC battery from CATL (out of which 2.5 kwh are reserved as buffer). There is no way to limit its charge other than to manually unplug it, which I can't always do, and most of the time it charged to 100% but I never let it stay at that high SOC for long. My commute is 80km daily and 170km once a week. The car has 75000km and so far I don't see any reduction in its range. Ambient temperatures are 25-35c with 2-3 months where its ~10c. I don't know the state of health as I don't have the tools to check it. I believe the best use of these studies as well as some others is for programming the BMS, which has significantly improved the longevity of batteries.
Think of it like your own stomach. Don’t wait too long before you eat (get too empty). When you eat don’t eat too much. Basically, be diligent and mindful about it.
There is no way to equate the number of cycles to the life of the battery without considering the frequency of charging. It mathematically incorrect to state that 2000 DST cycles is equivalent in years when you cycle 100-25% versus 75-65% because the frequency of the cycle is vastly different. You would cycle far fewer times at 100-25% as compared to 75-65%. I believe what is more important to the life of the battery is to operate between a range of say 70-20%. That is, try to minimize charging to 100% and draining it below 20%. But, thanks for presenting the data.
I also have a Tesla and drive about 20 miles per day, so it's easy to manage SOC within a range. I set mine at 70% and charge whenever it falls below 50%. I have a Model 3 SR (not +), so its range is software limited to 220 miles (vs. 240 for the SR+) or about 8% off the top. Also, I have the timer set to charge at 2am when the battery and air have cooled down and to minimize the time it sits in the garage at the higher SOC. With all that said, I'm assuming that I'm keeping my actual SOC roughly between 40% and 60%. Using this method, I haven't noticed any change in range after 5 years of ownership (advertised for 220, but my actual range is 208 by dividing SOC miles by the SOC percentage since I never charge to 100%) with the caveats that I don't know how the software limits range as the battery degrades and not charging to 100% doesn't allow for recalibration. After watching your video, I decided to re-set my max SOC to 60%, but still charge whenever it drops below 50% and reset the timer to have the car charged for a departure time of 7am. This means I'll be plugging in everyday instead of every other day. Not a big deal for me.
Thanks very much for this article - mate (Adelaide Aussie). I have an LFP Tesla (2023) and only use 4% each day to and from work (as per your assemssent of average). So i dont need to charge it more than once a week unless we drive it into the country side...ie over the weekend. What this site doesnt say is how to optimally charge an LFP battery. Now as you know Tesla says to charge it up to 100% once a week, but having read most of the article on the linked site, this doesnt make complete sense - espcially for low km Aussie's. Have you done any further reading on LFP since writing this and can you comment on my assessment from this reading - to only charge (even an LFP EV) up to about 85% and down to 45% to optimise battery longevity? PS I have a trickle charger and a 7.0kw charger (Tesla Wall Connector -V#3) so I can nominally do what is best...just need to get peer review advice? PPS dont like following generic models made for masses. P
LFP batteries are different. They "need" to be charged to 100% more often then other Lithium Ion type batteries. I have LFP batteries as home storage and the manufacturer updated their warranty requirements from charging once a fortnight to 100%, to now that they require once a week charging to 100%.
Great info, thanks! Take away when converting DST cycles to total kWh (and therefore total km): Charging from 25% to 75% is the best of the tested scenarios (same as 45% to 75% when considering 90% capacity retention, but more practical AND better when considering 85% capacity retention). My battery (I assume all / most?) is not allowed to discharge to less than 20%, and not allowed to 'fast charge' to more than 80% which is sensible based on the above. Best outcome would be to let battery get close to zero range (20-25%) then trickle charge at home to 75-80%. DO NOT CHARGE TO 100% as this had a bigger impact on life cycle than whether the battery was discharged to 50% or 25% (25% to 100% same total kWh as 50% to 100%).
One more thing to consider is the usable battery capacity. Depending upon the model that range can be from 90 - 96% very roughly from only looking at a couple of models. That's programmed in by the manufacturer to ensure that the battery does not charge to 100% and shorten the battery life. Check this out and maybe you can charge your battery to a higher level than you may otherwise think.
I travel for work and leave my car at the airport for 3 or 4 days in a row every week….so I have to account for phantom drain. I’ve stopped using sentry mode on my Tesla since it consumes about 10% per day 😯. Without sentry mode it only consumes about 1% per day.
I have been slowly transitioning my home to all electric. It was built with normal natural gas service for appliances. I first installed solar and a Power Wall. Then I installed a heat pump. I am in the process of adding a heat pump water heater and induction stove. I had intended on getting a Tesla Model 3 but the size wasn’t acceptable. By the time the Model Y came out I became aware of Aptera and I like their BEV solution much more than any other focusing on efficiency instead of electrifying a conventional vehicle. I am in California on the central coast so we have mild weather making it much easier. Good luck with your transition.
True, some people think that SuC supercharging will kill your batteries but that is just not true. We have several Model S cars and have mostly charged at SuC 10 years almost every day ( we drive 160 km every day back and forth and 350.000 km now drive on each still only lost 10% of original capacity. The secret is use or loose. Drive every day and charge 10-70% when required.
I don't have an EV but setting the max charge cutoff point at 90% and start charging only when battery drops below 50% should be a great compromise as the 2 biggest battery killers are heat of which more is generated when a charging battery is reaching full capacity and frequency of charge/discharge cycles. It works for my laptop battery which is now 5 years old and still has excellent battery health.
Thing is, unless you are using an OBD monitor to get into some data, that 80%-90% on your car's infotainment/cluster may actually represent a different actual % of the battery, which may have segmented or reserved a certain amount for core functions and protection. Example: 80% is a generally accepted number for most batteries, but Volvo recommends 90%.
I think it's important not to become a slave to a charging regiment. The 2 biggest criteria are; a) try never run the battery to zero; & b) don't overcharge. The rest is very much horses for cources if you consider the scenario below. Say your battery can deliver 300 miles of range and you do 300 miles p.m. You could charge from 0 to 100 % once a month, or just over 4 times if you charged from 25 - 50%. If over time you don't get much more than 4x more cycles out of your battery than the 0 - 100 scenario, you haven't gained anything other than inconvenience. If you created a chart called Total Kwhr charged over total time, the scenarios wouldn't be extremely dissimilar (assuming no complete discharges and say no 100%/over charging scenarios).
so living in a high heat area such as phoenix keep charge to below 75% and drain to 65% will help keep the battery life. and for local trips this will be enough juice as it should be enough for 20 miles of driving with a 60 kilowatt battery in a 4000 lbs. car.
To be CLEAR about the chart he referenced, the "number of DST cycles" is a single event of whatever the key says. For example, the orange line indicates 75% -> 65% or only 10% of battery capacity. At that rate, it hits 90% battery life after ~9000 events. The battery has supplied 10% x 9000 cycles or 900 times original battery capacity. The next one down (purple) is using 30% each time and did 4500 cycles before hitting 90% battery life, or 1350 times original battery capacity. The light blue line is 2900 x 50% or 1450 times original capacity. Therefore, the light blue line gives you most amount of energy before the battery hit 90% of original capacity. My guess is the test didnt exactly leave the battery down for long after discharging the prescribed amount which could favor the light blue line further. The best habit would be to plan your "charge to" battery level to spend an even amount of time on either side of 50% and also not allow the total charge level (lowest charge state to highest charge state) to swing more than 50%. I would like to see the test repeated with the orange line being 55% to 45% instead of 75% to 65% and purple being 65% to 35%.
Im late to your post but I just bought a long range model Y and the data is solid. I too drive low km which is 20 miles per day or 32km. I think 60% is ideal at slow charge and no supercharge but I like to share another wrinkle I add. Which is a 80% charge 3-4 times a month. And also a 100% charge once to every other month. There’s variables we can’t account for and need to break rules time to time.
This is a very good video, but while you may limit the charge level of your ev battery to anything less than 100%, it is recommended that you try to charge the car to 100% once in awhile, say monthly or every 2 months so that the battery cells can be balanced.
Excellent video! Extremely useful for those of us contemplating the purchase of our first BEV; gives us an idea of how to charge for maximum battery life. Many thanks!
I have an LFP standard range Tesla, I saw a study where a lab did 90-100% cycles and got about 10,000 cycles out of LFP (probably at 20 C). And that happens to be about my daily usage so most days I do a 10% depth of discharge with maybe a few times a month I go down to 70-80%. Interesting that colder is better. Good thing it doesn't get too hot here in NZ Good advice for NMC batteries. But, if you have LFP you may not need to worry as much, just top it up regularly. The rest of the car will probably fall apart first. LFPs have a flatter voltage curve and my understanding is that 100% allows the battery monitoring system to re-calibrate as it is hard to track the percentage on a flatter voltage curve.
The only point I would add is that these cycles would have been done sequentially in a short timeframe so does not factor in calendar degradation. You may have a DoD of 10% meaning technically your battery will be at 90% after 20 years but calendar degradation would have also reduced your capacity possible at a rate of 1% or more a year. If you combine calendar degradation with cyclic degradation you will could actually find yourself under 70% capacity after the 20 years.
Thanks for the source of the study. Very useful. However, your analysis lacks a critical component, which the study had, the Energy Units used. Someone else commented on this below. When I apply that together with the estimated milage, I get that the 75-25 is the absolute best. For my Taycan Turbo to get just under 90%, assuming 3.5kms range per KW, it gives me about 50% (75%-25%) * 93.4 KW (capacity) * 3500 cycles * 3.5 kms = 572,075 kms before getting just below 90%. Driving about 5,000 kms per year, that's 115 years (assuming time factor does not degrade the battery ). 75-65 gives only 10%*93.4KW*9500*3.5 = 310,555 kms. One of the worst, with 100-40 being the absolute worst.
One thing they only touched on was optimal charge rate. I do not use super charging with my model S, I do charge it at 2Kw/h (230V x 10amp) or 7Kw/h (230 x 32amp) My Max charge level is 70% for most driving or 90% for longer distance driving. Otherwise great info.
Keep in mind, a major factor is the chemistry of the battery. Lithium Iron Phosphate is far superior for battery life and seems to be being adopted where maximum energy density is not required. A list of models employing LFPO chemistry may be helpful.
😢 in the small print of Tesla warranty on the battery, is written that if you not mostly charge to 80 % the 8 years warranty is void. My friend had to buy a new battery after 4 years.
I plan to buy a 2024 Model 3, which will be my first EV. The information in this video is extremely helpful and easy to understand. I sometimes read comments from people who feel EV's are too complex, but really, they're far simpler than the ICE vehicles I've owned. EV's just have their own unique maintenance requirements, and far less of them 😊
Hi Robert, please note that the information in this video applies to the older battery chemistry, containing Nickel, Manganese and Cobalt. It doesn't apply to newer Lithium Iron Phosphate chemistry. The LFP battery does need to be charged to 100% regularly and there is some evidence it can develop a memory if only partially charged. You should check to make sure which type of battery is in your new EV.
Thank you for the very interesting video. Two questions: 1. Is the same rule applies to modern mobile phones? (iPhone, Samsung, etc) 2. 10% DoD is 6000 cycles from 0 to 100% or from 90 to 100%?
One thing, and probably the most important thing that wasn't covered is the total distance each different charging cycle would give you before it goes down to that red line you drew. How many kilometres of driving it reaches it. What you'll find is that there's very little difference. The difference is that with one car you're doing let's say 150,000 kms in 23 years but in the other car you're doing the 15,000 kms in 3 years. The thing that would make the biggest difference in the battery life is whenever possible, don't use those fast charges, unless of course you have to. It's like giving someone an X amount of free fuel. For someone who only drives 20 kms a day it will last then ten times longer than someone who travels 200 kms a day.
The 1C charge rate means charging the whole battery in one hour. Most people rarely do this since they charge at home. A more typical rate would be 1/10 C, which the studies did not use.
of the factors that a user can control, deep discharges are the number one thing to limit or avoid all together. after that charging the battery to 100% is next. to understand this, think of inflating a balloon. it is easy at first, but takes more and more pressure as it gets near capacity. this stresses a battery as it does a balloon, which is why most chargers slow down the charge rate above 80%. 3rd is charge intensity (rapid charging, supercharging etc). your battery much prefers to drink from a garden hose, not a fire hose. try to keep these intense sessions short - 15 minutes if you do it frequently. 30 minutes on trips as necessary. leading to the 4th - charge duration. it is much better to have daily short charges (top offs) than weekly 5 hour sessions. the longer the battery charges, the hotter it gets and heat is your enemy. as mentioned, 50 or 60% is a pretty ideal state for a battery, so average drivers are fine charging to 60% every day, even if they only used 5 or 10%. the 40-60% range suggested should be fine as well. for those that drive a lot every day and need more juice, use the 80%-20% rule. this wont give you uber long 20 yr battery life, but 10+ years isnt unreasonable. also, don't freak out if you go on a few road trips each year - charge it up to the top and go. it's still a car meant to go places conveniently, and stopping every 20% to charge makes a long trip miserable. it wont seriously shorten longevity unless you start doing it often. The Toyota Prius has a controller that keeps it's battery in the 80%-20% range, and there are hundreds of 20 year old cars out there with original NiMH battery packs, which are no where near as durable as the Lithium cells used today.
I purchased a new 2013 Chevy Volt. The battery size is 16.5 KW. It automatically had a built in buffer for high & low charge cycles. No confusion, no questions, just plug it in and walk away. That is the way all EV's should be. Plug it in and don't worry about it. The manufacturer should set the parameters. They set the warranty.
Legislation sets the warranty. The US Federal government requires manufacturers to offer an eight-year/100,000-mile warranty on all EV batteries. California does one better, mandating a warranty of 10 years or 150,000 miles. The European Union, as well as the United States, China, the United Kingdom, Japan and South Korea, have reached an agreement under the UN World Forum for the Harmonization of Vehicle Regulations bill, car manufacturers must guarantee that batteries may not lose more than 20 percent capacity in five years or 100,000 km (whichever comes sooner). After eight years or 160,000 km, the degradation should not exceed 30 percent. Manufactures using NMC should know the mean live span and inform their buyers. LiFePo4 is now the majority of BEVS so they will outlast an ICE with abuse.
@@waynerussell6401 What they don't tell you is that if the traction battery is replaced under warranty, it does not mean you're getting a brand new battery pack. More than likely you're getting a reconditioned pack. And I doubt the new warranty is for another 8 yrs/100k miles. I don't expect the sales people to know about the charging parameters of the car, but the manufacturer should state the guidelines. It shouldn't be quesswork.
1) Tesla actually defines the useful life of the battery to be 70% (at least that's the threshold for their warranty claims). Of course, as long as the battery is serving its purpose, basically you could keep using it far after even 70%. Though, it will severely limit your range for long road trips. 2) This is why the bigger battery you get, the nicer it is. Even if you're not going to use the range. Because the bigger battery you have, the easier it is to stay in the sweet spot. The bigger battery you have, the less impacted you are by loss of range, whether you loss that range due to aging battery, or because of the weather, etc. Of course, it's also nice to just have that extra range when you need it.
I usually consume 10% per day, I charge every day at 230V 10A (i dont have three phases) to 70%. Every morning I have 70% battery and potential 300km - but I need 10-50km every day :-)
I was also told about every 3 months or so I should let the battery go low 10% or lower then charge back up to 100% just to keep the cells all active .Most of the time I have been charging from 50% to 80% I can easy change to 30% to 60% . Thank you.
Thank you, finally some real research based information! I think I'm gonna reduce my charges to 80% from now on and charge twice a week instead of trying to go all week on one charge 🙂 Have you found any info about cell balancing? Some say that you should charge to 100% once a month to balance the cells
Thanks for sharing this. My daily commute is 30kms through motorway which means I don't really need to worry about battery range. I can also recharge less often, keeping within ideal state of charge.
On average 750km per week. Charging at home. No issues with Tesla Model 3 2024. Also a awesome car to drive and great comfort. Better than any other car I've been in.
I find your video very interesting. I have a PHEV with a range of 40 miles if I follow your figures the electric range would be very low and certainly not worth the extra cost of buying a PHEV
Yeah, this is an interesting one. I know of Volvo PHEVs, apparently they have a buffer of ~20%. And those do not let you discharge less than 10% and charge more than 90%, which should help significantly, but still, those 80% of charge between 10 and 90 are likely to all be used and quite frequently. Volvo gives an 8 year warranty for the battery, not sure what level of degradation is considered not a warranty case though.
My policy has been only charges fast as you have to and don't let the battery sit at 100%, but also do what you have to. With my 23 bolt EV I'm going to lower my Max from 200 or 180 charging every other day to 160mi, charging daily. I charge at 16 amps because I have the time
When you say "storage is not going to be an issue for us since we're pretty much driving our cars every day", I'd suggest that every moment the battery exists is "storage time", never mind not driving. In my opinion ambient temperature is the #1 issue for those that go the extra mile to care for their EV battery.
If going on a road trip, I wonder if it is better to charge to 100% at home then charge from 10 to 60% at the Super Chargers or to only charge to 60% at home prior to the trip and then charge 10 to 60 at SCs.. On one hand, it may require slightly more SC usage, but on the other, the depth of discharge in a single drive would be lower and you would never get above 60%.
If a person only discharges from 75% to 65% then they would likely charging every day, meaning that 9000 charge cycles / 365 is 24 years; however, a person who discharges from 85-25% likely only charges once per week, so that would equate to 2000 / 52 = 38 years. When you calculate the number of charge cycles remember to also include the time between charges.
My understanding is that fast charging is far more deleterious to EV batteries than the trickle charging you would typically do at home. But yes, I don't see the need of fully charging your EV at home every day if you aren't draining the battery significantly during the day. Probably every second or third day would make more sense, and makes for one less thing to think about. After all, you don't top up your petrol car every day when it falls to an 7/8 or 3/4 tank, typically you would wait till you have an 1/8 or 1/4 full tank.
Fast charging isn't an issue. Only fast charging is an issue. The car "wants" AC while fast charging is DC so you should make sure to charge with AC once a week.
@@lachlanB323 Fast charging cooks the battery and should be used sparingly. AC charging doesn't undo that damage once it is done, unfortunately. Eventually, every battery cell will fail, it's just a matter of how long it takes. A battery pack can last 20 years if charged correctly. It can also last only one year, as happened in the case of the Uber driver Dobson on Kim Java's channel who fast charged twice a day for a year and had to replace the batttery.
@@apterachallenge If Dobson charged his Tesla once a week through AC his car would of lasted much longer. Charging fast doesn't hurt batteries, heat does. But Tesla's have a good cooling system so they don't overheat while charging. The problem is DC charging not the rate at which you charge. But charging with AC once a week helps a lot
@@lachlanB323 All charging is DC charging. Yes, you supply an AC current to the vehicle when "AC charging", but the onboard inverter changes it to DC so the batteries can accept it. It's the intensity of the charging which damages the battery, and the "AC charging" from a household power point is only different from the DC charging you get at public chargers because it's 2-7kw instead of 100kw or more.
PLEASE NOTE:
This information is intended for EV owners who only drive a short distance each day and then plug in each night. The data presented only applies to ternary type lithium batteries (e.g. NMC), not Lithium Iron Phosphate (LFPO). If that isn't your situation then don't waste your time watching or posting irrelevant comments.
Also note that a "DST Cycle" referred to in the Battery University study means one discharge and recharge to the levels specified in the test (e.g 75% - 65% SOC). However the industry term "cycle", when used to predict battery life, means one transition from fully charged to fully discharged and back to fully charged. So there would be 10 X 75% - 65% events before one charge "cycle" is clocked against the battery's lifetime cycle count.
While the science may seem complex the key message is simple:
- You don't need to change your lifestyle or stress about your battery
- You can keep driving as you do currently and plugging in each night so your car is always ready at the start of the day
- If you simply lower the maximum State of Charge (SOC) from 90% to something more appropriate, like 60% this can enhance the longevity of your battery. This is because the battery spends less time standing with a high SOC.
Lastly, I am not telling anyone what they should do, just presenting the science. In the end it's your car and your choice how you charge your EV. Have a great day ! 🙂
All irrelevant if you have a car on a 2 year lease
Just charge it and enjoy it 🎉
@@rambleon1182 yeah don’t worry about the car only lasting a few years because the battery is naffed. We’ll just get a new one anyway, and tech is changing that quickly that you’ll want the new tech anyway.
@@jlrguy2702
Exactly they are not cars just mobile tech platforms with a very short real life buy a new ev now and in 2 months it will have lost 50%of its cost price just get a good old V8 muscle car and enjoy your drive
You should revoke the video or at least the commentary, because the advice you give is leading to increased battery degradation. As others point out, the light blue line would result in the maximum extracted charge before reaching 90% soh.
I think the math is a little off here. Since let's say your commute is the 10% you're talking about. If you would do the 100-25% charge, you can drive for 7,5 days before charging (so 7,5*1000/365=20 years), while with the orange line you need to charge daily. So if you look at it that way the light blue and pink are the best modes 5*3000/365=40 years or 3*5000 which is the same. 40 years seems very unrealistic to me, since you will have so degradation over time itself (storage). So all in all I don't think the factory 80-25 is all that bad. Maybe 75-25 or 75-40 might be bit better. I now charged up to 80% so I think I'll set it to 75 instead. My commute takes a bit more of the batter though, about 15%.
I agree, you need to convert the number of cycle and DoD into KWh and then you can see which strategy have most battery life (in term of power discharge until battery degrade to 90%)
From the last chart I think the 25-75 charging strategy @ 3000 cycle will output most energy before reaching 90% battery degradation.. putting that number for my ionic 5, that translate to around 108,000kwh power discharge and @ 5km / kWh (low estimate), the battery will last 540k km. At 25k km per year that is 21 years of driving... So that means after 20 years I will still have 90% battery capacity. But I live in tropical country and the normal temperature here is around 33°c and sometime I charge to 100%. so maybe 10 years is more accurate estimation.
The terminology is confusing. In battery technology, a cycle is considered full capacity of the battery. So a 10% charge is 1/10th of a cycle.
@@lampe36there is no true understanding of cycles except for general term of cycle meaning the returning of a state.
So short cycle is a cycle that is not equal to a long cycle which is also a cycle. A cycle is a cycle but not all cycles are the same. Measuring longevity in cycles is a terrible unit to use in most cases when cycles are not the same cycle. It’s like comparing the price of things in pennies but some things are in Australian pennies, some in Euro pennies, some in American pennies, and etc.
So I agree on both the math being odd, and radically unequal “cycles”… however, given I usually drive < 20 miles, it will have zero impact on my life if normal daily charging is to 75%.
@@BrianThorstadyes it’s pretty much the same thing I said about my civic when I was offered a regular oil change versus a synthetic oil change. Is it really going to make a difference?
I own my model P85 for 10 years already. Not a sign of battery degradation because I never charge above 80 %. When I don't use my car for a while it stays on 50%. Then when I am going for a trip I charge the power I need for this particulary trip.
Sometimes I supercharge up to 80% to heat the battery to
get a temperature to remove condensation and water out of the battery pack. Corrosion in the electronics also damages it.
Still super satisfied with my Tesla after 100.000 miles.
Did ever any cell failed as it happens to ebikes all the time? One cell goes out and you have to buy a new battery, for it's too expensive to fix it. I wonder what happens in a car. Do they separate like packages of 6 or 12, and the system just jumping over them? Maybe they can be replaced? Can you enlighten me, please?
It is possible to repair a car's battery, it is better to treat the battery discribed in this video. Cars have a smart battery management system (BMS) , this holds the battery healthy.
Your battery may seem fine but you should have it serviced at a non Tesla shop anyway. Replace the butterfly valves and reseal the battery. After 10 years the valves will be filled with dust particles and will let moisture get inside.
I do not see why I should let someone take "care" of my cars battery, only to let them earn some money ? Have no fear for dangers that never appear , thats how my generation avoids unnecessary stress. I sometimes charge on a supercharher and let the fans cool my bettery , I do not drive in streets with 10 cm's of water and I don't drive in winter when salt is on the street, then the car stays in the garage and I use my Mercedes E type T modell. I balance my battery every year once and see how long it lasts. Do I need a new battery pack in the future ? So what ? I paid my model S P 85 cash in 2014 and I can pay a new battery pack without any problem. That's the comfort of saving money instead of going on vacation 3 or 4 times a year. Our second home in Germany gives us all we want.
You may not notice any signs of battery degradation, but they still degrade naturally due to time. You also have to take into consideration things like temperature, depth of discharge and cycling. Not charging above 80% definitely helps to prolong battery life, but there are additional steps you can take beyond just the basics in order to maximize your battery's lifespan.
In our training from GM for the Bolt EUV we have been told to recommend to customers that they use the moto ABC: Always-Be-Charging. Their explanation was that the car will manage the battery temperature while the car is parked. One fellow on TH-cam has a short video showing his Bolt expelling excess heat during a very hot day. His car wasn't running, just plugged in. So while not charging everyday may be a good idea that would be only when the outside temperature is neither too hot or too cold. At least where GMs are concerned.
Charging to a lower level most of the time seems to be a good idea that most agree on. My cell phone has a battery management setting that you can switch on and it limits the charge to 85%. This is meant to increase battery life (Samsung phone).
I drive a Bolt EUV and have set my maximum charge at 80%. I may lower that to 75%. I also use slow charging as it seems to be recommended by most.
Thanks for the video. I found it most useful. In addition, the comments left by some viewers also contributed to my battery education.
Thanks for adding to the conversation Phil. You make some good points here. I think your suggestion is probably the best approach. Plug the car in each day but set the maximum SOC to the minimum you will require to complete your daily commute. In my case I only travel 14kms (7 miles) each day so I can get by with charging to just 60% and only increase this if I'm planning a long trip out of town.
The reason GM likely instructs people to always charge their car, is because it reduces range anxiety, performance is at its peak, you'll likely never get stranded with a dead car, all of which reflect poorly on the car/EVs. Manufacturers dont care if 7 year old cars have decreased battery health, they already profited, and arguably degrading battery health means consumers buy more cars. What is best for manufacturers isnt always best for consumers.
I have a Bolt EUV and follow the ABC mantra. However, I set my max charge level to 80% on the Charging settings so its never fully charged. Only when we go on roadtrips do I take that setting off.
the reason why is because the bolt is more willing to use the battery heater or cooling system when plugged in but when not plugged in, it doesn't want to drain battery so let the battery heat up.
The really up to date vehicles have heat pumps to manage the battery temperature.
I was charging to 80% and then only charging when less than 50%. Since, on my daily commute, I always came in right at about 50%, I am going to only charge up to 70% and see how it goes. I am also intrigued by potentially charging at a lower rate too. I can recharge in two hours, but I have 8 hours to do it in over night so am giving that a try too. Thanks for the food for thought.
A lithium-ion battery is happy between 25% and 80% SOC. However the BMS needs to know the extremes as well so do go to them occasionally. It is okay to charge to 100% but it is bad not to use this first 10-20% shortly after: like if a battery being under stress while fully charged: the shorter we leave it in that condition, the better. So please just charge to 100% the night before occasional long distance trips.
And happier between 20-50%. At the end it’s about adjusting to your daily usage
That's why I am glad to see the data, otherwise we only have stuff like "battery is happy" to base decisions on. Batteries are incapable of being happy.
My usage varies from 20 to 110 miles each day. I charge my 2021 Ford Mach E at home to 90% daily as recommended in the owners manual. With over 60,000 miles on the odometer I don’t see much degradation. Charging to 90% still shows 238 miles of range
@@irfanhusein1445 That's fine but there is little reason for you to not drop it to 80%.
@@AlexLplusbattery is happiest at 50%, so 35-65% would be much better than 20-50%. That's too low to go if you are trying to extend battery life to the max.
The magenta (75%-45%) most closely represents my usage cycle and I charge twice a week which = 43 years (I'll be 106 years old)
btw - the warranty is 80% and I had a starting capacity of 331 miles so at 90% I still have 300 miles of range & (80% = 270 miles) which is still quite usable
Can certainly be more than 30% degradation in winter.@didyuknow
@didyuknow more like stick with an ice vehical. ev owners have to be insane. dont use the heater, use blankets and the seat warms. what kind of ghetto cars are these.
@didyuknowpeople think it's the cabin heater that draws all that energy, but most of it is battery heating. Keep the heater on 😂
Most battery capacity is loss just from yearly losses without even using the battery He showed a chart on this, so you will lose about 2-4% of capacity a year just by not using your battery.
I've been looking into this question for a week now and finally came across some actual data! Thanks!
Been basing my model 3 LR off the 75%-25% line, and the battery is doing well, the car is at about 110,000 miles in 4 years. Just plug it in every night, and every morning it's at 75%, much less than is needed for a typical day.
This is good advice. Keeping the EV battery balanced is the best for longevity. I got a 14 year old Prius and can monitor the battery charge level. Toyota seems to keep the battery between 45 and 60% charged. It is still running well on the original battery.
original prius and even new hybrid do not use lithium battery, they use NiMh
@jeangoupil8129 I have a 2023 Toyota Prius Prime XSE Premium, and it has 13.6 kWh Lithium Ion battery.
Thank you for this information. Very useful. I’m now trying to keep my SOC between 40%-60%….so re-charge when the SOC is close to 40%. This works for me as i tend to drive less than 20 miles each day. It make sense that the battery is “happiest” around 50% SOC. I’m also avoiding fast chargers when possible.
I put over 250,000 miles on 4 plug-in hybrids over the last 10 years. They had a built-in battery buffer of 20%, so that "100%" charged/full was actually only charging up 80% of the battery. The result was that none of the PHEVs showed ANY visible loss of range during the time that I had them. Granted, because 20% of the battery capacity was not shown to the driver, they could have lost up to 20% of their capacity without it being seen. But they also could have actually lost minimal battery capacity over the years of daily driving and charging (L2) use.
What plug in hybrids do you have? And how is the battery after 10 years?
It lasted that long because the majority of those 250,000miles where driven with an ICE engine.
If someone uses the electric part of their hybrid a lot, the battery cannot last that long, because the battery will go through charge cycles like crazy.
If a hybrid does 30miles on it's battery for daily driving and someone would actually do those 30miles every day on the battery, they would have accumulated more than 1000 full cycles in less than 3 years.
@@Tschacki_Quacki hyundai have done tests where battery management can give battery up to 8,000cycles!
@@niallchurch2679 Yes, if you use the battery only between 40% and 60% you probably get 8000 cycles.
A laboratory is not real world usage.
You omitted the fact that part of this 'precautions' are already done by the BMS auromatically. If you charge to 100%, this is not really 100%, as the battery physically has 8% or so more capacity, which is 'fenced off' by programming in the BMS. Similar at the low end...
You pulled that out of your ass. Could be 1%, could be 20%. But yeah, you just know it's 8% or so. "Trust me bro"
Also important to remember that most manufacturers don’t allow you to use the entire battery. So 100% is not really 100% and 75% is not really 75%
That doesn't really matter for the SOH of batteries however, looking at charging cycles
@@authorified89 why not? my battery is gross 35,5kwh, im only allowed to charge it to 30 kwh, if I charge it to 90%, that will be 27 kwh, and it would be 76% charged. My soh Im assuming is worked out from how many kwh i can get from the votlage that gave me 30 kwh when car was new.
@@bjorn2fly oh I misunderstood then, 75% of 35 kWh is significantly different from 30kWh indeed. Its good to keep in mind the actual battery percentage instead of what the car shows, my bad
I guess tesla is not one of them. %100 is almost true value I think. So we have to pay attention to charging.
Tesla have about 4kWh bottom lock on larger packs. I.e. when a 100kWh battery shows 0% it's true percentage is 4%. You can't use this 4kWh. There is also top lock but I don't know the figure. @cigersuz
Excellent points, Mark.....thanks for doing the hard work to investigate the subject. I would add though that it is important to prriodically charge to 100% SOC, in order for the battery management system in most cars to perform cell balancing. Perhaps adopting a routine that the first day of each month, you charge to 100% using level 1 or 2 charge point, and return to your regular routine for the rest of the month, would preserve battery maintenance and maximize service life. Thanks again for doing this.
TH-camr bjorn said that after charging to %100, you need to discharge all the way to 0-5% at one go to calibrate bms system. Not just charging to %100 and then discharging in a week or so.
(Not LFP then?)
@@lindam.1502lfp should be charged to 100% daily anyway.
I'd save that 100% charge for when you are doing a long trip, timed to end just before you set off, and run it down to 10% to help balancing. No need for once a month, they take 6 months to get out of balance in my experience (Tesla S since 2016). My old S still held 95% original capacity after 87,000 miles.
A significant variable to degradation is also depth of discharge (DOD). Avoiding large depth of discharge prevents expansion and contraction of the electrodes which leads to cracking. A DOD 10% to 20% has a little impact on battery degradation above 20% has increasing impact. 20% of discharge provides very little degradation above 10%, but provides twice the mileage driven. Therefore the ideal charging range is in fact 40 to 60%, pushing this to 30 to 70% may be ideal for most peoples practical usage with the additional small degradation being worth the increased usability.
Great video. Thank you so much for your work on this. Leaving a comment to show my appreciation, and also to express that for a very technical subject, this video gives a perfect explanation and context of how to optimize your EV's battery life. Cheer my friend. Thanks again!
Thank you victor! 😊
We just traded our 12 year old Prius C for a 2024 Prime. The Prime is our third hybrid but first PHEV. The C had 128,000Km on "the clock" and from the beginning gave between 4 & 5 l per 100Km (dependant on ambient temperature). Regards charging cycles; its battery was just under 1kw, so, it was constantly being charged and discharged every time it was driven. At about ten years, the battery would no longer gather enough charge to run the car in EV Mode (which even when new, was limited to 1~2Km's. But, even with that constant charge/discharge rate, the litre's per 100Km performance did not decline.
The new Prime's Traction Battery is close to 13 times the "size" of the C's. It incorporates a charge "buffer" of (I think), 10% lower and upper, meaning there's 80% of usable charge. Yesterday, I drove the Prime 88Km in EV Mode and the Trip Computer indicated there was 6% charge left. The car would have exceeded 90Km on battery. This morning, the computer stated the range would be 91Km.
For us, the Prime is essentially a BEV. After 5,000Km we have used just 1.5 tanks of fuel. Based on the length of service the C's battery gave, we have no concerns about the level of charge/discharge with the Prime. The Traction battery has a ten year warranty, we plug-in every night and don't worry about cycles.
Spot on!
We LOVE having plenty of fuel in the tank with an ICE car. We also LOVE having plenty of charge in the battery for an EV, but for the majority of us that’s complete overkill.
HOWEVER keeping the max charge below 65% to 70% is always going to be much better for the battery …. and even more so in hot climates.
If you must fill it, don’t leave it there for long, drive immediately.
If you arrive home near empty, charge it to at least 20% immediately.
Interesting my BYD has a 60KWhr LiFePO blade battery configured 126S1P.
The recommendation is to charge it to 100% once per week. Our daily driving during the week uses about 60%. Consequently we slow charge it (AC3KW) each Sunday (mainly using solar panels) to 100%.
We only fast charge on trips, typically at the 50KW rate. Under fast charging, charging efficiency and rates decrease markedly over 85%, with a good deal of energy lost as heat. So when fast charging we normally stop at 80-90%, particularly if the weather is warm. The BMS rolls the fast charge back anyway over 90%.
On trips we mainly operate between 15% and 90% for an effective range of 300km between top ups. On routes we mostly drive, this works well.
So far we have not detected any battery degradation.
Really interesting... thanks for your research and clear summary. My charging routine was to use the 80-20% range but after this, i’m going to follow your recommandation. Apart of course when i’m doing à road trip. Then i slowly charge to 100% during the night befor departure, and using my obd connector, capture the capacity of the battery so that i can follow up battery degradation. ( i have a mustang mach e with edtended battery)
This is good information. I drive my Ioniq 5 about 40 km daily and charge level 2 free at work several times weekly. I think it is reasonable to lower my end charging a bit, dropping from 80% to 70% with a goal to keep the battery between 40-70% state of charge. My understanding is that the Ioniq 5 needs to be above 40% state of charge to recharge the 12 volt battery. Thanks for posting this.
Very valuable information. I have owned a model Y for almost 3 years and have been reviewing charging advice videos. This is the best one I’ve seen by far. Thank you.
Thank you Frank!
@frankpainter7571 Be aware that your Tesla model Y uses a lithium phosphate battery, so has different recharge characteristics than those covered in this video.
Were we live and work, lots of people travel over 100 miles per day. So my Leaf, uses 75 to 80% per day. Current at 48000 miles. And the car came with extra warranty on the battery.
Thank you. It kind of fits what I knew about batteries (storage % voltage for batteries waiting to be shipped and sold by battery companies is 65%). Until now I was charging my car at 80% every day (Model Y 2023, Long Range). Now, I will charge my car to 60%, use 3% to get to work, it will stay on parking at work and lose 2% more during the day (sentry mode usage-security), then lose another 3% on its way back, then it will be at 52% and stay that way until the charging start 3 hours later. Friday, I will charge to 80% in case of a longer driving during the weekend.
Even better - charge to 75% twice a week and extra at weekend if you need it.
@@sybaseguru Nope, not in my case. I can't trickle charge more than 17% in a night . And the charging automation of the car work per day so I do not want to manually modify the charging of the car via the app every other day. I have peace of mind the way I am doing it at the moment.
@@mletouutube What? 17% per night? What the hell is charging your car? A solar panel for the moonlight?
@@Tschacki_Quacki Get back to arithmetic class man. 3%+2%+3%=8%
WOW. I've heard some of this info before, but this is the most in-depth explanation. THANK YOU for putting this all together for us!!!
Some of what he said is very misleading. 80% - 20% could give you 2000 @ weeks of cycles. Battery will die of old age first.
@@MrSummitville I believe that may apply to LFP which has many more cycles, not NMC discussed in this video.
@@mikemotorbike4283 What does not apply? Aging?
Because most people use less than half the battery pack’s capacity each day, a new Swedish study charged cars up to 50%, and then charged them back up to 50% after use. They got spectacular improvements to battery pack service life vs. charging it to any other amount.
All battery manufacturers say to avoid going under 20% SOC, they say that on their spec sheets; and to avoid going over 80% too.
Thank you, Mark. An excellent piece of reporting with a clear conclusion which is easy to implement. I will start this immediately.
Thank for the positive comment David!
This is the most useful information I ve got about optimum state of charge . Sincere thanks from a fresh Astra E owner
The info, as presented, is misleading ... 80% - 20% between recharge yields 2000 @ weeks. Battery will die of old age first.
I know my iPhone batteries have a lifespan more than double the length of everyone else in my home. And usually longer runtime each charge. Everyone else plugs their phone in overnight daily so it’s “fully charged” each day. I never plug in until after I get the 20% warning and whenever I am able, try to unplug between 80-90%.
The info in this video seems to concur.
Ternary Lithium Batteries (NCM and NCA) should normally be operated around the 50% capacity level. An example of this is when your daily round trip only requires you to charge the battery up to 60% when you leave home, and the battery drops to 40% when you return. So the battery is only cycling around the 50% of full capacity. If you keep doing this regularly, then your battery degradation will be practically immeasurable for a very long time.
All wonderful theory. But.. a vehicles BMS handles a lot of this. Cars are now coming with 7 year unlimited km warranties, incl battery, so this might suggest the manufacturer has thought about what end users may or may not do. Limiting yourself so religiously to using such a small % of a battery is very counter to the whole driving experience and can become an obsession. There are so many variables indicated that affect battery longevity that you zero control over. Here in Australia, days and weeks go by where temps well exceed these "lab tests," and I would guess the same is true in European winter based climates where it goes below zero. The alternative to all of this science and maths, etc, is to enjoy the car you drive in the climate conditions that prevail for you and use common sense and manufacturers recommendations given they cover your warranty 😀
People want to keep these cars for way longer than 7 years, hence the video. Manufacturers care little about after warranty. It's like when they say only change the oil every 20,000 miles. They want the car to die after warranty expires. Although Tesla battery packs are lasting 420,000 miles from 2017 cars and growing. Refurb packs I wouldn't trust from earlier cars.
The question should be how much will the cost of the battery will be 5-10 years from now to replace. Might only cost a few thousands to replace a battery at the rate of how fast the cost is dropping. Also, by then there will be more fast charger available like gas stations. So do u want to pay a little extra for less inconvenience?
Very interesting, I have set mine for daily drive to 65% charge and discharge will land around 40% as I use about 25% on my daily commute. No degradation yet after 3.5k miles.
Thanks for this interesting video. My Megane e-Tech EV60 is always charged at 80% and when the percentage is down to 60,50 or 40%, I charge at home with 7 kWh (32A). After one year, Renault told me the battery is of 98% capacity. Now, after hearing what you told, I’ll switch fom 80 to 75%.
Cutoffvoltage at tesla is at 3.3v so 0% charge is actually more or less 10-15%
Time at max or min charge, is equally important as the charge level. In other words, don't leave your battery charged at a higher charge level or a lower charge level for a long period of time.
I use about 25-30% battery on my 132km daily commute. I now charge to 60% and arrive back home with 30-32% remaining. I’ve noticed a phantom discharge always occurs in the hours after arriving at my work when the SOC at the time I park is in the 59% to 69% range. I generally loose 3-5% SOC level while parked at work 8 hours. My daily commute is 132km RT. I’ve adjusted my daily charging so when i arrive at work, my battery is less than 55%. My main emphasis is always avoid parking for any amount of time with a battery level above 58%. I find i consistently gain a few percent battery if i arrive at work with 50% or less.
When these tests were performed were they using an actual car and the cars BMS, or were they just testing battery packs or even just cells in a lab setting? Seems the the manufacturers BMS would have a pretty large influence on the batteries and their lifespans, regardless of how much or how little you were charging.
EDIT: Just looked at the article - they were testing batteries for handheld devices, not batteries for automotive use. Not sure these guidlines can be carried over directly.
The basic principles about battery chemistry and how it behaves still apply.
The same tests have been made with all kinds of cell formats and the results show obvious tendencies.
You need to normalize the data for amount of battery used. For instance the 75-25 cycle gets you 5x the driving distance of 75-65 yet it lasts more than 1/5 of the cycles. So based on this chart a 75-25 cycle seems to be the best option. Just don’t charge it every day.
I’d take a look at you median daily drive and make sure that you battery covers probably 3-4 times that distance at minimum. Then plug it in only when you get to 25% and then charge to 70 or 75%.
There is also time degradation which is why you don’t want an overly massive pack unless you do frequent long trips.
Basically the first gen electrics with 100miles or so range are probably the sweet spot for most people.
@marksjustimagine I understand and agree with the logic of not charging to 100% or discharging to near zero, however, one major flaw in the approach is that charging more regularly (daily) from 35 % to 75% SOC (40% for say 160 km) would require twice as many charging sessions as one charging cycle from 10% to 90% (80% for 320 km)
Number of charging sessions doesn't matter much. It's the total number of charge cycles. One cycle being from 0% to 100%. So topping up by 10% each time, would take 10 sessions to complete one charge cycle of 100%.
Great video. I feel you nailed in your sum up and what you are personally doing with the 40 - 60% cycle, a pity that study didn't include that or even 45 - 55%. I think this rule of thumb would also be great for someone who can only charge by fast charger, if they are also an urban dweller whose commute is short, then they could do this just once or twice a week for probably only ten minutes a time and end up way better off than those who fast charge huge depth all the time.
Also I'd be very interested to see the results if it was dialled back even more to say 20 - 40%, the battery is charging very quickly at this stage because it is under virtually no stress. Could be even better than that mid range.
Just an amateur thinking out loud here :)
Graph at 12:00 : it appears that Yellow is better than purple - but its not. The purple covers a 30% cycle min/max- 3 times more power than the yellow (10% cycle min-max), so I need only charge up a third of the number of times. In fact purple has half the number of cycles at 90% capacity retention, so is providing 50% more mileage. Purple looks optimum on this basis so one should aim for keeping charge in the 45% to 75% range, but dropping to 25% is not a disaster as the blue line shows only a minor degradation hit.
Isn't Black the best then, by this logic?
Really good. Thanks. This one is well researched -- and there isn't any hidden agendas. There is so much bad information out there. My Tesla S has 216,000 kms -- and I've lost about 10% of capacity. I've tried to stay between 20%-80% SOC but I do many road trips so 50% of my charging has been on superchargers.
Is warranty out yet? If so, get ready for that $20k battery bill. It’s coming! 😂
own a BMW after its out of lease and Warrantee ? get ready for 2K a year minimum for the next 10 years of ownership and many tows.... at least Tesla's servicing and maintenance over the life of the car are far less than ICE engines.@@JetFire9
@@JetFire9 From where do you know how big the battery is in OP's Tesla and how long it's going to last? 🤔
Can you tell me when I need to replace the battery for my 2015 DeWalt drill and how much a new battery costs? Thank you 😊
@@Tschacki_Quacki Stupid reply. Try again.
Very helpful. I think that everybody can get its own lessons. I lowered my limit from 80% to 75% which would mean that my car would sit most of the day in the 55-65% SOC range. I also delayed my scheduled charge in the am so that I drive it only about half an hour from reaching 75%. This seems to fit my driving pattern the best and hope I will be a happy owner for a long time (MY LR).
Ma va là non spararle
Thank you for doing the research/hard work for me. This has helped me greatly. We have a 2023 LR Model Y and use just under 40% total charge each workday. We have been following the recommended 80% charge each night, only going above for long trips. I will now change our daily habits to ‘bracket 50’. 70% max overnight…car will rest at work at @50% during day, having us just over 30% when we get home. This seems to be the closest scenario to the purple/orange line on the ‘stress test’ table for us.
Again, awesome work and many thanks for your research.
PERFECT, bracketing 50% is perfect and mimics what all, all, all Li-ion battery manufacturers say to hibernate your battery, as at 50% you stress it least and protect against depth of cycle.
14 km, you could very easily replace your car with a bicycle.
Lol
If battery is preconditioned it does not damage from fast charging. There are charts online that compare battery degradation of Teslas that are often supercharged and others that are rarely supercharged. The degradation is almost identical.
There are two ways to measure cycle life. One, is to count the number of times the car is driven, and the number of times it is plugged in to recharge. The other way, is to measure throughput. That is the total number of amp hours the battery puts out over its lifetime, divided by its rated amp-hour capacity. (sometimes referred to as "equivalent cycles") I do believe this would be the most relevant, because that translates to the total miles the battery lasts in an electric vehicle, before it needs to be replaced. In many cases, the best margins would be between 30% to 70% states of charge. Most manufacturers recommend 30 to 80%, to use the middle 50% of total capacity on a day-to-day basis. Occasional charges to 100% aren't too detrimental, as long as the car is driven immediately after the full charge, and is done only on the occasional long trip where you really need all the capacity the battery has to offer. You don't want to charge to 100%, then leave it at that state of charge for a full day.
I was looking at the cycle life graph of a Trojan golf cart battery, (liquid filled deep cycle lead acid)and calculated the total equivalent cycles, and it didn't make any difference whether the battery was discharged 80% down to a 20% state of charge, or, if it was drawn down 20% to an 80% state of charge. The total ampere hours available over its lifespan was the same! (keep in mind, Lead Acid batteries REQUIRE charging to 100%, to avoid sulfation)
Thanks Vincent for your contribution to this discussion. Indeed it is the second way that most manufacturers use when publishing battery warranty. The key take away from the Battery University study is that, as you suggest, the worst thing you can do is charge to 90+% and then leave the car standing for a day, or even overnight.
I see lots on this topic about batteries for full EVs though very little for a PHEV which what I happen to have (Mazda CX-90 PHEV 17.8-kWh lithium-ion battery). I am finding I my daily driving is in the 40km to 60km range, occasionally farther which is when the gasoline engine comes in handy but I did buy it with the idea that the majority of my driving would be in EV mode. My car has only about a 40km electric range and trying to keep it in the 20% to 80% range generally recommended for batteries means the usable electric range would be reduced to only 24km which is not much at all. I understand that for a PHEV the battery never really gets to 0% no matter what the gauge on the dash shows but I don't know what it actually does go down to.
When I questioned my dealer they said charging the battery to 90% daily is fine (at home not fast charge) and I don't worry about how low it goes, I let the car's software deal with that. If I am away for a month or more, which does happen from time to time, I store it with about a 50% charge. I've only had the car for a year so it's hard to tell if I am doing the right thing or not. I've no idea what will happen long term and no one seems to be able to tell me.
Most EV owners fixate on charge levels, but do not consider a major portion of degradation is due to time, not much you can do about that, except to keep the car away from high temps.
They fixate on charge levels because that’s about all they can control.
Time/age is not controllable so of course they discount it.
And keeping it away from higher temps has no impact on time/age.
I guess the least I can do is share my experience.
I own a 2021 MG ZS EV with a 44.5 kwh NMC battery from CATL (out of which 2.5 kwh are reserved as buffer).
There is no way to limit its charge other than to manually unplug it, which I can't always do, and most of the time it charged to 100% but I never let it stay at that high SOC for long.
My commute is 80km daily and 170km once a week. The car has 75000km and so far I don't see any reduction in its range.
Ambient temperatures are 25-35c with 2-3 months where its ~10c. I don't know the state of health as I don't have the tools to check it.
I believe the best use of these studies as well as some others is for programming the BMS, which has significantly improved the longevity of batteries.
Thanks for the video. I have used the Battery University's advice with my Lead acid batteries. They have so lasted over 10 years.
Think of it like your own stomach. Don’t wait too long before you eat (get too empty). When you eat don’t eat too much. Basically, be diligent and mindful about it.
State of charge % and depth of discharge don't exist in a vacuum, both time and temperature are significant contributing factors.
There is no way to equate the number of cycles to the life of the battery without considering the frequency of charging. It mathematically incorrect to state that 2000 DST cycles is equivalent in years when you cycle 100-25% versus 75-65% because the frequency of the cycle is vastly different. You would cycle far fewer times at 100-25% as compared to 75-65%. I believe what is more important to the life of the battery is to operate between a range of say 70-20%. That is, try to minimize charging to 100% and draining it below 20%. But, thanks for presenting the data.
I also have a Tesla and drive about 20 miles per day, so it's easy to manage SOC within a range. I set mine at 70% and charge whenever it falls below 50%. I have a Model 3 SR (not +), so its range is software limited to 220 miles (vs. 240 for the SR+) or about 8% off the top. Also, I have the timer set to charge at 2am when the battery and air have cooled down and to minimize the time it sits in the garage at the higher SOC. With all that said, I'm assuming that I'm keeping my actual SOC roughly between 40% and 60%.
Using this method, I haven't noticed any change in range after 5 years of ownership (advertised for 220, but my actual range is 208 by dividing SOC miles by the SOC percentage since I never charge to 100%) with the caveats that I don't know how the software limits range as the battery degrades and not charging to 100% doesn't allow for recalibration.
After watching your video, I decided to re-set my max SOC to 60%, but still charge whenever it drops below 50% and reset the timer to have the car charged for a departure time of 7am. This means I'll be plugging in everyday instead of every other day. Not a big deal for me.
Thanks very much for this article - mate (Adelaide Aussie). I have an LFP Tesla (2023) and only use 4% each day to and from work (as per your assemssent of average). So i dont need to charge it more than once a week unless we drive it into the country side...ie over the weekend. What this site doesnt say is how to optimally charge an LFP battery. Now as you know Tesla says to charge it up to 100% once a week, but having read most of the article on the linked site, this doesnt make complete sense - espcially for low km Aussie's. Have you done any further reading on LFP since writing this and can you comment on my assessment from this reading - to only charge (even an LFP EV) up to about 85% and down to 45% to optimise battery longevity? PS I have a trickle charger and a 7.0kw charger (Tesla Wall Connector -V#3) so I can nominally do what is best...just need to get peer review advice? PPS dont like following generic models made for masses. P
LFP batteries are different. They "need" to be charged to 100% more often then other Lithium Ion type batteries. I have LFP batteries as home storage and the manufacturer updated their warranty requirements from charging once a fortnight to 100%, to now that they require once a week charging to 100%.
Great info, thanks!
Take away when converting DST cycles to total kWh (and therefore total km):
Charging from 25% to 75% is the best of the tested scenarios (same as 45% to 75% when considering 90% capacity retention, but more practical AND better when considering 85% capacity retention).
My battery (I assume all / most?) is not allowed to discharge to less than 20%, and not allowed to 'fast charge' to more than 80% which is sensible based on the above.
Best outcome would be to let battery get close to zero range (20-25%) then trickle charge at home to 75-80%.
DO NOT CHARGE TO 100% as this had a bigger impact on life cycle than whether the battery was discharged to 50% or 25% (25% to 100% same total kWh as 50% to 100%).
One more thing to consider is the usable battery capacity.
Depending upon the model that range can be from 90 - 96% very roughly from only looking at a couple of models. That's programmed in by the manufacturer to ensure that the battery does not charge to 100% and shorten the battery life.
Check this out and maybe you can charge your battery to a higher level than you may otherwise think.
I travel for work and leave my car at the airport for 3 or 4 days in a row every week….so I have to account for phantom drain. I’ve stopped using sentry mode on my Tesla since it consumes about 10% per day 😯. Without sentry mode it only consumes about 1% per day.
I have a M3P and sentry mode loses 0.9 miles of range per hour
@@mikeforwardukhow mucb is that in percentage
Great info! Thanks 4 taking the time 2 make this video. God Bless!
Thank you, you're welcome!
I have been slowly transitioning my home to all electric. It was built with normal natural gas service for appliances. I first installed solar and a Power Wall. Then I installed a heat pump. I am in the process of adding a heat pump water heater and induction stove. I had intended on getting a Tesla Model 3 but the size wasn’t acceptable. By the time the Model Y came out I became aware of Aptera and I like their BEV solution much more than any other focusing on efficiency instead of electrifying a conventional vehicle. I am in California on the central coast so we have mild weather making it much easier. Good luck with your transition.
Oh good your going to overload the electric grid. Great idea ...
True, some people think that SuC supercharging will kill your batteries but that is just not true. We have several Model S cars and have mostly charged at SuC 10 years almost every day ( we drive 160 km every day back and forth and 350.000 km now drive on each still only lost 10% of original capacity. The secret is use or loose. Drive every day and charge 10-70% when required.
I don't have an EV but setting the max charge cutoff point at 90% and start charging only when battery drops below 50% should be a great compromise as the 2 biggest battery killers are heat of which more is generated when a charging battery is reaching full capacity and frequency of charge/discharge cycles.
It works for my laptop battery which is now 5 years old and still has excellent battery health.
Thing is, unless you are using an OBD monitor to get into some data, that 80%-90% on your car's infotainment/cluster may actually represent a different actual % of the battery, which may have segmented or reserved a certain amount for core functions and protection.
Example: 80% is a generally accepted number for most batteries, but Volvo recommends 90%.
I think it's important not to become a slave to a charging regiment. The 2 biggest criteria are; a) try never run the battery to zero; & b) don't overcharge. The rest is very much horses for cources if you consider the scenario below. Say your battery can deliver 300 miles of range and you do 300 miles p.m. You could charge from 0 to 100 % once a month, or just over 4 times if you charged from 25 - 50%. If over time you don't get much more than 4x more cycles out of your battery than the 0 - 100 scenario, you haven't gained anything other than inconvenience. If you created a chart called Total Kwhr charged over total time, the scenarios wouldn't be extremely dissimilar (assuming no complete discharges and say no 100%/over charging scenarios).
so living in a high heat area such as phoenix keep charge to below 75% and drain to 65% will help keep the battery life. and for local trips this will be enough juice as it should be enough for 20 miles of driving with a 60 kilowatt battery in a 4000 lbs. car.
To be CLEAR about the chart he referenced, the "number of DST cycles" is a single event of whatever the key says. For example, the orange line indicates 75% -> 65% or only 10% of battery capacity. At that rate, it hits 90% battery life after ~9000 events. The battery has supplied 10% x 9000 cycles or 900 times original battery capacity. The next one down (purple) is using 30% each time and did 4500 cycles before hitting 90% battery life, or 1350 times original battery capacity. The light blue line is 2900 x 50% or 1450 times original capacity. Therefore, the light blue line gives you most amount of energy before the battery hit 90% of original capacity. My guess is the test didnt exactly leave the battery down for long after discharging the prescribed amount which could favor the light blue line further. The best habit would be to plan your "charge to" battery level to spend an even amount of time on either side of 50% and also not allow the total charge level (lowest charge state to highest charge state) to swing more than 50%. I would like to see the test repeated with the orange line being 55% to 45% instead of 75% to 65% and purple being 65% to 35%.
Im late to your post but I just bought a long range model Y and the data is solid. I too drive low km which is 20 miles per day or 32km. I think 60% is ideal at slow charge and no supercharge but I like to share another wrinkle I add. Which is a 80% charge 3-4 times a month. And also a 100% charge once to every other month. There’s variables we can’t account for and need to break rules time to time.
This is a very good video, but while you may limit the charge level of your ev battery to anything less than 100%, it is recommended that you try to charge the car to 100% once in awhile, say monthly or every 2 months so that the battery cells can be balanced.
Excellent video! Extremely useful for those of us contemplating the purchase of our first BEV; gives us an idea of how to charge for maximum battery life. Many thanks!
I have an LFP standard range Tesla, I saw a study where a lab did 90-100% cycles and got about 10,000 cycles out of LFP (probably at 20 C). And that happens to be about my daily usage so most days I do a 10% depth of discharge with maybe a few times a month I go down to 70-80%. Interesting that colder is better. Good thing it doesn't get too hot here in NZ
Good advice for NMC batteries. But, if you have LFP you may not need to worry as much, just top it up regularly. The rest of the car will probably fall apart first.
LFPs have a flatter voltage curve and my understanding is that 100% allows the battery monitoring system to re-calibrate as it is hard to track the percentage on a flatter voltage curve.
LFP last longer at lower state of charge, too. Lab tests do not included 5 years of aging!
The only point I would add is that these cycles would have been done sequentially in a short timeframe so does not factor in calendar degradation. You may have a DoD of 10% meaning technically your battery will be at 90% after 20 years but calendar degradation would have also reduced your capacity possible at a rate of 1% or more a year. If you combine calendar degradation with cyclic degradation you will could actually find yourself under 70% capacity after the 20 years.
Thanks for the source of the study. Very useful. However, your analysis lacks a critical component, which the study had, the Energy Units used. Someone else commented on this below. When I apply that together with the estimated milage, I get that the 75-25 is the absolute best. For my Taycan Turbo to get just under 90%, assuming 3.5kms range per KW, it gives me about 50% (75%-25%) * 93.4 KW (capacity) * 3500 cycles * 3.5 kms = 572,075 kms before getting just below 90%. Driving about 5,000 kms per year, that's 115 years (assuming time factor does not degrade the battery ). 75-65 gives only 10%*93.4KW*9500*3.5 = 310,555 kms. One of the worst, with 100-40 being the absolute worst.
One thing they only touched on was optimal charge rate. I do not use super charging with my model S, I do charge it at 2Kw/h (230V x 10amp) or 7Kw/h (230 x 32amp) My Max charge level is 70% for most driving or 90% for longer distance driving. Otherwise great info.
Keep in mind, a major factor is the chemistry of the battery. Lithium Iron Phosphate is far superior for battery life and seems to be being adopted where maximum energy density is not required. A list of models employing LFPO chemistry may be helpful.
i still have the 2011 first gen nissan leaf with 70% capacity left, i only slow level one charge up to 80% daily commute and about town for errands.
Do you feel some loss of power from motor? Anyway, congratulation for owning same EV for 12 years, amazing!
Thanks for putting this explanation together. It's easy to follow and is well supported by evidence.
😢 in the small print of Tesla warranty on the battery, is written that if you not mostly charge to 80 % the 8 years warranty is void.
My friend had to buy a new battery after 4 years.
I plan to buy a 2024 Model 3, which will be my first EV. The information in this video is extremely helpful and easy to understand.
I sometimes read comments from people who feel EV's are too complex, but really, they're far simpler than the ICE vehicles I've owned. EV's just have their own unique maintenance requirements, and far less of them 😊
Hi Robert, please note that the information in this video applies to the older battery chemistry, containing Nickel, Manganese and Cobalt. It doesn't apply to newer Lithium Iron Phosphate chemistry. The LFP battery does need to be charged to 100% regularly and there is some evidence it can develop a memory if only partially charged. You should check to make sure which type of battery is in your new EV.
Thank you for the very interesting video. Two questions:
1. Is the same rule applies to modern mobile phones? (iPhone, Samsung, etc)
2. 10% DoD is 6000 cycles from 0 to 100% or from 90 to 100%?
One thing, and probably the most important thing that wasn't covered is the total distance each different charging cycle would give you before it goes down to that red line you drew. How many kilometres of driving it reaches it. What you'll find is that there's very little difference. The difference is that with one car you're doing let's say 150,000 kms in 23 years but in the other car you're doing the 15,000 kms in 3 years. The thing that would make the biggest difference in the battery life is whenever possible, don't use those fast charges, unless of course you have to. It's like giving someone an X amount of free fuel. For someone who only drives 20 kms a day it will last then ten times longer than someone who travels 200 kms a day.
The 1C charge rate means charging the whole battery in one hour. Most people rarely do this since they charge at home. A more typical rate would be 1/10 C, which the studies did not use.
Very useful info, thank you. I'm going to drop my maximum charge level setting tomorrow from 90 to 75.
of the factors that a user can control, deep discharges are the number one thing to limit or avoid all together. after that charging the battery to 100% is next. to understand this, think of inflating a balloon. it is easy at first, but takes more and more pressure as it gets near capacity. this stresses a battery as it does a balloon, which is why most chargers slow down the charge rate above 80%. 3rd is charge intensity (rapid charging, supercharging etc). your battery much prefers to drink from a garden hose, not a fire hose. try to keep these intense sessions short - 15 minutes if you do it frequently. 30 minutes on trips as necessary. leading to the 4th - charge duration. it is much better to have daily short charges (top offs) than weekly 5 hour sessions. the longer the battery charges, the hotter it gets and heat is your enemy. as mentioned, 50 or 60% is a pretty ideal state for a battery, so average drivers are fine charging to 60% every day, even if they only used 5 or 10%. the 40-60% range suggested should be fine as well. for those that drive a lot every day and need more juice, use the 80%-20% rule. this wont give you uber long 20 yr battery life, but 10+ years isnt unreasonable. also, don't freak out if you go on a few road trips each year - charge it up to the top and go. it's still a car meant to go places conveniently, and stopping every 20% to charge makes a long trip miserable. it wont seriously shorten longevity unless you start doing it often. The Toyota Prius has a controller that keeps it's battery in the 80%-20% range, and there are hundreds of 20 year old cars out there with original NiMH battery packs, which are no where near as durable as the Lithium cells used today.
Simple 80% - 20%. 100% once in a while to reset the SOC / Fuel Gauge
I purchased a new 2013 Chevy Volt. The battery size is 16.5 KW. It automatically had a built in buffer for high & low charge cycles. No confusion, no questions, just plug it in and walk away. That is the way all EV's should be. Plug it in and don't worry about it. The manufacturer should set the parameters. They set the warranty.
Legislation sets the warranty.
The US Federal government requires manufacturers to offer an eight-year/100,000-mile warranty on all EV batteries. California does one better, mandating a warranty of 10 years or 150,000 miles.
The European Union, as well as the United States, China, the United Kingdom, Japan and South Korea, have reached an agreement under the UN World Forum for the Harmonization of Vehicle Regulations bill, car manufacturers must guarantee that batteries may not lose more than 20 percent capacity in five years or 100,000 km (whichever comes sooner). After eight years or 160,000 km, the degradation should not exceed 30 percent.
Manufactures using NMC should know the mean live span and inform their buyers.
LiFePo4 is now the majority of BEVS so they will outlast an ICE with abuse.
@@waynerussell6401 What they don't tell you is that if the traction battery is replaced under warranty, it does not mean you're getting a brand new battery pack. More than likely you're getting a reconditioned pack. And I doubt the new warranty is for another 8 yrs/100k miles. I don't expect the sales people to know about the charging parameters of the car, but the manufacturer should state the guidelines. It shouldn't be quesswork.
Great info to think about. It’s a similar discussion to how many kms should you drive before an ICE oil change for maximum longevity.
1) Tesla actually defines the useful life of the battery to be 70% (at least that's the threshold for their warranty claims). Of course, as long as the battery is serving its purpose, basically you could keep using it far after even 70%. Though, it will severely limit your range for long road trips.
2) This is why the bigger battery you get, the nicer it is. Even if you're not going to use the range. Because the bigger battery you have, the easier it is to stay in the sweet spot. The bigger battery you have, the less impacted you are by loss of range, whether you loss that range due to aging battery, or because of the weather, etc. Of course, it's also nice to just have that extra range when you need it.
I usually consume 10% per day, I charge every day at 230V 10A (i dont have three phases) to 70%. Every morning I have 70% battery and potential 300km - but I need 10-50km every day :-)
Let the battery discharge lower before recharging.
I was also told about every 3 months or so I should let the battery go low 10% or lower then charge back up to 100% just to keep the cells all active .Most of the time I have been charging from 50% to 80% I can easy change to 30% to 60% . Thank you.
That should only be applied to LFP batteries.
Thank you, finally some real research based information! I think I'm gonna reduce my charges to 80% from now on and charge twice a week instead of trying to go all week on one charge 🙂
Have you found any info about cell balancing? Some say that you should charge to 100% once a month to balance the cells
Thanks for sharing this. My daily commute is 30kms through motorway which means I don't really need to worry about battery range. I can also recharge less often, keeping within ideal state of charge.
On average 750km per week. Charging at home. No issues with Tesla Model 3 2024. Also a awesome car to drive and great comfort. Better than any other car I've been in.
I find your video very interesting. I have a PHEV with a range of 40 miles if I follow your figures the electric range would be very low and certainly not worth the extra cost of buying a PHEV
Yeah, this is an interesting one. I know of Volvo PHEVs, apparently they have a buffer of ~20%. And those do not let you discharge less than 10% and charge more than 90%, which should help significantly, but still, those 80% of charge between 10 and 90 are likely to all be used and quite frequently. Volvo gives an 8 year warranty for the battery, not sure what level of degradation is considered not a warranty case though.
My policy has been only charges fast as you have to and don't let the battery sit at 100%, but also do what you have to. With my 23 bolt EV I'm going to lower my Max from 200 or 180 charging every other day to 160mi, charging daily. I charge at 16 amps because I have the time
When you say "storage is not going to be an issue for us since we're pretty much driving our cars every day", I'd suggest that every moment the battery exists is "storage time", never mind not driving. In my opinion ambient temperature is the #1 issue for those that go the extra mile to care for their EV battery.
If going on a road trip, I wonder if it is better to charge to 100% at home then charge from 10 to 60% at the Super Chargers or to only charge to 60% at home prior to the trip and then charge 10 to 60 at SCs.. On one hand, it may require slightly more SC usage, but on the other, the depth of discharge in a single drive would be lower and you would never get above 60%.
If a person only discharges from 75% to 65% then they would likely charging every day, meaning that 9000 charge cycles / 365 is 24 years; however, a person who discharges from 85-25% likely only charges once per week, so that would equate to 2000 / 52 = 38 years. When you calculate the number of charge cycles remember to also include the time between charges.
My understanding is that fast charging is far more deleterious to EV batteries than the trickle charging you would typically do at home. But yes, I don't see the need of fully charging your EV at home every day if you aren't draining the battery significantly during the day. Probably every second or third day would make more sense, and makes for one less thing to think about. After all, you don't top up your petrol car every day when it falls to an 7/8 or 3/4 tank, typically you would wait till you have an 1/8 or 1/4 full tank.
Fast charging isn't an issue. Only fast charging is an issue. The car "wants" AC while fast charging is DC so you should make sure to charge with AC once a week.
@@lachlanB323 Fast charging cooks the battery and should be used sparingly. AC charging doesn't undo that damage once it is done, unfortunately. Eventually, every battery cell will fail, it's just a matter of how long it takes. A battery pack can last 20 years if charged correctly. It can also last only one year, as happened in the case of the Uber driver Dobson on Kim Java's channel who fast charged twice a day for a year and had to replace the batttery.
@@apterachallenge If Dobson charged his Tesla once a week through AC his car would of lasted much longer. Charging fast doesn't hurt batteries, heat does. But Tesla's have a good cooling system so they don't overheat while charging.
The problem is DC charging not the rate at which you charge. But charging with AC once a week helps a lot
@@lachlanB323 All charging is DC charging. Yes, you supply an AC current to the vehicle when "AC charging", but the onboard inverter changes it to DC so the batteries can accept it. It's the intensity of the charging which damages the battery, and the "AC charging" from a household power point is only different from the DC charging you get at public chargers because it's 2-7kw instead of 100kw or more.