Some years ago I installed an extra 4 kWh battery pack in my 2008 Toyota Prius, it consisted of two packs 24V of 6 LiFePO battery banks in series. The 48V was then converted into 200V and set parallel to the existing battery. After a couple of months the capacity dropped rapidly and the BMP kept moving charge from one cell to another. I decided to take the BMS completely out of the system and within two weeks the cells fully recovered and I got the full capacity back. The problem with a BMS is that it looks at voltage only, not charge. Nice explanation, thanks for the video!
Great explanation. Most people that complain and criticize never actually do what they are criticizing about. On the other hand, you are speaking from experience! Keep up the great videos!
I didn't need the long-drawn-out and simplified explanation of why some batteries may need balancing while others do not... but you did such a magnificent job at it that I just continued listening for fun lol 😅👍
Haha I love how the video end with your high hopes for the drone to help storytelling and it crashes at first launch. I almost picked myself. Keep up the good work sir you are not only brilliant but entertaining at the same time
Nicely explained and clearly stated. When most of us recycle all kinds of 18650 cells from old laptop batteries I'd bet most of us worry about charging and discharging them out of recommended voltage ranges. I just use two B6 chargers to manage the individual parallel banks so they are balanced. Since the cells vary wildly I never get them perfectly balanced but as you said, when they discharge at a rate of 2 amps each it doesn't matter.
I finally got your point, Jehu. so it's not so much about perfectly matching cells, it's about designing the whole pack big enough that your discharge rate per cell stays below the discharge rate of the worst performing cell. Now, how do you track that discharge rate cells, by the way ? do you write down how long it takes to discharge from 4.1V to 3.2V ? I guess i can do this with the BTC3100 which tracks mAh and time elapsed during discharge (processing 4 cells separately at 1A "in parallel"). waddyathink ? Thanks amigo. Keep on trucking ! (from France)
I flew RC heli's with those sort of LIPO packs and many I knew didn't balance charge EVERY time; we would check the voltages of the individual cells, but often that was a cursory check done towards the end of charging, and /or as part of pre-flight. We would preach to new flyers to always balance charge, but that crowd often used the manufacturer's charger which charged thru the balancing leads anyways. However, we often didn't practice what we preached; there were many other factors far more important than balance charging.. In an ideal world, we'd balance charge every pack; but it takes longer, and always bleeds out some power doing so.
Great video, and e need some help here.... I have a electric scooter 48v/52v 18ah battery and the BMS died, can i remove the BMS, and start to cherge the pack by the thick positive and negative wires? Without the risk of explsion..? i only have a 42volt battery charger that i use in my electric scooters, lke Ninebot and Xiaomi... thanks on advance :)
When charging batteries to 100%, the cell balancing becomes most relevant since outliers will cause overcharging. If the overall regulator stops at 80-90% charging, the cell limits are not reached and balancers would not even activate. This also increases battery life to the greatest extent. LiFePO4 Chemistry is far less sensitive to overcharging (at low currents) and incidentally is very efficient.
great video man, there was an article in march version of home power magazine that covered this very nicely, they took 48 cells all manufactured from the same place and on the same day, they then split them into 2 groups, they made packs of 4 cells. on 6 of the packs they installed a very commonly used universal battery balancer on them. then they left the other 6 un-balanced as a pack, then they ran them under loads using the same load over and over to simulate usage on the cells to use up the cycle life of the cells tell the capacity of the cells starts to drop. in the testing they found out that the cells that were hooked up to a battery balancer during its charge cycle reached its 1/2 cell capacity limit 37% faster than the cells left unbalanced, the theory behind this is that when the balancer is balancing the cells its applying a micro load the cell that needs balanced in the pack and when it does this the pack voltage drops and the charger sees this drop in voltage and starts charging the pack over and over tell the cell is considered balanced, these micro loads and charge cycles during the balancing phase takes micro portions off the cell cycle life over time, resulting in that cell wearing out quicker... the only benefit of balancing the pack is to get slightly longer pack life out of a single charge when in use... the more cells you have in a pack that spreads the amp draw reduces your need for balancing, because the cells will stay closer in voltage as the cell capacity increases on the same load over time..
Thats really interesting. Do you have a link to this article? I think for my off grid batter bank I will be going down the route of LiPo, Hobbyking has some great deals right now on some packs and I can build a 1.5kwh 48v ish pack for very cheap. My concern was balancing but I think I will go down the route of a Meanwell variable 1.5kw supply that I can vary by a microcontroller. This will monitor cell / pack voltage and give me complete control. I have balance chargers already so no problem doing a balance charge every 10 cycles perhaps?
Entertained and highly informed. I enjoy your relaxed, friendly and authoritative style. Makes me feel comfortable heeding what you say and confident to act upon your advice... Thank you.
Another great video! Thanks for sharing. Would you mind showing how you figure out what the weakest cell in a group is? Also, in a large pack (or maybe a small one?), is there a standard C rating per cell that you try to stay below during max charge/discharge current to ensure that all cells in the pack will charge evenly? Unrelated, but I'd love to see a follow-up to your bottom-balancing video - one where you demonstrate the process and how it's done. :)
This is probably the most informational video I have seen yet on conceptualizing a battery pack for my electric vehicle. Thank you for clarifying many things. My vehicle is powered by two 500 watt, 48V hub motors. The current battery pack consists of 4 Sealed Lead Acid 12 volt batteries. Very heavy and doesn't deliver the range I need. My desire is to build a Life Po battery pack of 14s7p to provide me with 550-720 watt/hours of use. with 98 cells, I was confused about balancing vs. monitoring. Your explanation of power drain was very helpful. Since there is doubt in my mind about many of the Balancers ability to actually balance cells, I think I will stick with not having a BMS. It make further sense as I will not be requiring more than 20 amps of power at any time (most likely 10 amps steady), so the drain should be low compared to the capacity (below 2C if I am correct). Thanks again.
I just have a question I have build 60v battery pack 20ah with lishen cell 4000mah after 4 months start to get fully charge 66.7 in place off 67.2 are this can be need balancing or thats normal
Hi Jehu, I just joined yesterday and today I opened a battery froma dead laptop and found all 8 cells are in good shape. I made a small battery bank and my led lights are working on that. Thanks for your teaching. Question:- after putting 100 used 18650 cells in a powerwall how to see ballance charging and which battery is stop working aftyer few months?
This was a helpful item you pointed out, it'll be useful to know the discharge rate of the lowest denominator battery in order to get an EV to run for longer. In student FSAE there is an endurance test which will benefit from this 🙂
Thank you JehuGarcia; this was a very helpful topic and you did an excellent job of explaining it. Btw; I like your T-shirt JAG35; nice graphics. Is it your creation?
Great video and I learned a lot. So for a large Lipo4 battery for a deep cycle application like a sailboat house batter bank with long discharge cycles for the most part, although sometimes pulling a lot of amps for the inverter, would a bms be needed? What is the disadvantages of a bms? I mean why not put one on if it would protect the bank ? Thinking of going with lithium for my next boat, and interested in building my own system. Thanks.
+Bob Fomenko cost, complexity, and reliability, the cheap ones kill more batteries than they save and the good ones are expensive especially when you realize they are not essential
I want to make a 18650 li-ion pack for my old motorcycle, but idk if I need to do 3 cells or 4? And does it need to be balance charged? I still need to check the voltage output of my '71 Honda CB350, but I need to upgrade the regular & rectifier to a newer combo unit first. But I'm just curious cuz I've seen lithium batteries on the market, specifically targeted for motorcycles, and they seem to be 4 cell packs with no charge circuit or BMS or anything at all. I just don't know if it would be ok to use one with a much older and less reliable motorcycle electrical system.
@jehugarcia if you don't use BMS, what is your methodology again in charging without one? I use a BMS but one time the BMS got busted and my LIFEPO4s got screwed.
great example demo. best I've seen I wanted to ask you a question: What do you think about charging a 52v 20ah Li-ion battery of an ebike without balancing? my BMS died a couple of days ago and I am debating whether to get a replacement BMS. I know how important it is to stop before low voltages and can do that with a precise monitoring app. I still have my old charger that I was thinking to modify so that each cell gets a maximum 4.1v instead of 4.2v. Thank you in advance for your help
I have one ? Is there a way to trickle charge my cordless drill battery’s during down time like months of not using them, I getting sick of buying battery packs because I forgot to keep them at 60 percent charge. I keep my motorcycle battery on a battery tender and it’s fine every year after sitting for the winter. Sorry to ramble on just getting frustrated with having to buy new battery’s for my cordless tools. Tools are lithium ion packs
There may be a risk that if even just one cell in a parallel bank develops a significant self-discharge current, it could cause that bank to reach 0% much sooner than the other banks? (and once the voltage plummets, the discharge current would then rapidly reverse charge the empty bank, killing it, even if it wasn't already damaged from the
Which is why the packs ( 7S ) I am building all cut out at 29.02 Volts. 7 X 4.145 with me charging them at 29 Volts max makes for cool LiPo batteries. At rest, they come in at 28.7 Volts which is 4.1 Volts per cell. Each pack of two parallel cells has a dual BMS board on the pack.
I have run my DIY powerwall for years with no balancing:) they stay balanced enough and every six months or so I'll manually balance them. Cells become unbalanced when you hit their limits all the time, I daily cycle my pack about 50% so lazy cells never get the chance to shift a pack.
Is it safe to use a 3V zener diode to protect a battery? The zener diode connected to gate of a MOSFET that controls the battery's output with a pull-down resistor of course.
A question. I want to power my Chauvet Slim Par 56 LED lights using 18650 Li Ion cells. The battery will be mounted on the outside bottom of the light instrument. My plan is to use 9 cells ... wiring 3 sets of three in series then connecting the 3 sets in parallel. May I ask your advice in wiring this battery and using the correct onboard (PCB) charger. Do I need to use balance wiring? I am hoping to get about 6 to 8 hours when fully charged. Thank you.....I love your videos/ Very informative.
Chingon, great info, got a grip of rechargeable packs, that won't charge. Now i have the knowledge of what shuts them down, balance of voltage, not heat or high ohms... 😮
As far as my understanding of batteries go, when you put batteries together they balance themselves take a fully charged battery and connect it to a used one, the full one transfers its energy to the used one until equilibrium is achieved
I made a parallel pack of five 18650 cells to run a small 3.5v lamp. I charged 4 of the cells individually to the exact same voltage and forgot to charge the fifth because I wasn't going to use any battery monitor for this pack. I solder all five cells together and leave it sitting there for about an hour. I remember I didn't charge the 5th cell so I disassemble the pack to charge that one cell. To my surprise all 5 cells were exact same voltage 4.1. I know that the 5th cell was 3.8v. I guess those 4 fully charged cells charged that last one to equal them all out.
You say you don't balance the cells, are you using a bms and letting that balance ? Or do you have some way of monitoring you battery health ? I'm looking at making my own pack and dont want to add in more expense or difficulty. If you have covered this already could you please post a link to the video Thanks
This is pretty cool. So i’m doing this electric catamaran boat project which is going to have two 48v 6kw outboard motors which will draw a maximum of 13kw in total, and power will be coming from 4kw of solar panels and 75kw of tesla modules. I have been looking for the right BMS for these modules, but after seeing this video i’m not really sure i need any BMS in my system. What do you think?
2 @ 6 kilowatt motors = 250 AMPS, is a substantial load ! You need to verify how much the low-end cell voltage varies under load, and how much the high-end cell voltage varies when fast charging.
hello i have a question for you i just made a battery pack with brand new samsung35E 15s6p with bms . Now in case i wanna charge it without bms can i connect the charger (60v 7 ampere) directly to the discharge cable?
Thank you, that is really informative. Absolutely it's down to application. I'm off grid running solar. I'm over sizing my bank which basically means I don't need to worry about balance and also maximize cycle life as the bank will be charged to no more than 80% and discharge to 25-30% of capacity. Hopefully this might lead to the bank lasting as long as I do. If I need serious power or very long run time, I just ramp up charge voltage and accept deeper discharge cycle. Great video...
Just charged my DIY 13s 4p 48v ebike battery I made without a BMS. This video gave me confidence to try it. Of course I monitored it's progress the entire time. Worked like a charm...Thanks for the info...
i have no idea what you are doing with your cells, if you are going to use 6000 of them to move a car around you have to balance them once them they will be fine for a few years
Very good video. It's hard to find good information about this topic on the internet. It would also be nice to have an explanation about the difference between series and parallel connection in regards to charging. To my knowledge batteries connected in parallel are quite forgiving if you don't balance them, while batteries in series can be dangerous if not balanced (with high load).
If I want to replace the nimh battery used in my RC truck with 18650 cells, do I need to include a balance lead? Would you consider this application a high drain? Total volt need is 14.4.
30amp continuous on each motor, it has two. How do I wire the cells in parallel to max the capacity? The truck use two 7.2V NIMH 6 cell, the battery bay can hold 4 18650 cells on each side (total of 8 cells), I know how to connect it in series, not sure about parallel.
On your EV do you have a system to prevent over discharge & over charge of the whole pack? Interested if you are having to manually prevent these possibilities or if you put some sort of electronic control in.
Using no BMS with my solar systems lifepo4 batteries, just top balancers & cell meters for some low voltage protection. working great, going on two years now...
Unless they are being overcharged, deep cycled, or carrying huge loads, it's generally not necessary to monitor and balance all the time. Once they are all at the same potential, they will tend to stay that way -- until a cell starts to die, which is why one should periodically check the levels across the pack. Cars have an active BMS to do this because no human is supposed to ever see the batteries. (it has to be 100% automatic, 100% of the time.)
Hi can I use 10 laptop cells in parralel 14 in series 140 in total they are half 2000mah and half 2200mah but all together so they will be 50 amps continuous 5a per cell can I use a 45 a bms with this pack it is only 5 a out will this be ok on a ebike
.so if i take two lithium ION batteries in series how much voltage i should give them to charging them ? if i give 8.4 volt for charging is it will be enough ?
Made 2 18650 battery packs. A 4s7p and 3s1p. Charged 4s7p using a 30v output connected to a buck charger. I set buck to 15.8 volts and limited current to 1 amp. On the 3s1p I used a 12v output adapter that plugs into 120v. On both, the BMS had an output and a charge input connection. I connected both to the BMS charge input to charge. The batteries worked great. But when I tried to charge the second time the charge wires got hot. On examination I found all batteries measured .4v. Should I not use the BMS charge input and just use the BMS output connection to charge? Lost a lot of money. Any suggestions will be appreciated. Probably not the proper place to post this but didn’t know where else to go. You are obviously very knowledgeable and maybe you can help. Thanks so much for your videos.
Good explanation, so I could do a powerwall using the cell log 8, or two of them to check my packs periodically? I think I remember you saying that you dont leave them connected because they ironically unbalance the packs over time?
I rewired a 2000 civic hybrid battery. Two cell packs together for a 17v system. I been charging them with my old school RV charger. No problems yet. Set it up with regulator to make 12v. Should I expect a issue.? I use for led lighting so far. No high wats.
Hi thanks 1- Can this( DELL J1KND 48WH 11.1VOLT )laptop battery be used as a power bank (without open it)and charged without laptop? 2. If possible, which board is suitable? 3- What pins are for charger and discharge connection? Please write an answer with Google translation into Persian I do not know english I can not copy here and past on google translate
Jehu, Forgive me for laughing out load at your expense. I watched this video and reached the end where you attempted to launch the drone from your driveway. I saw the thing power up and then flip over. And I thought...'Did I see what I thought I saw? Did one of the propellers launch by itself?' I rolled the video back about 10 seconds and hit play. YEP! A single propeller launched by itself before the drone flipped over. I'm sorry Bubba...but I almost rolled out of my chair because I was laughing so hard!!! I've watch several of your videos since discovering you a few months ago. I have picked up a lot of information from you and your videos. It is great information. I eventually want to build a battery-backup system for my home. But first, I want to build a portable but fairly powerful battery backup system that can run a few decently sized appliances. I am thinking about solar power, and have been watching DIY Solar Power with Will Prowse. Between the 2 of you, I don't think I can go wrong. You both provide insight about power storage from two different perspectives, and it is invaluable. Keep on doing what you are doing Jehu!
Hi i have build a 14s 6 battery 18650, can i charge my battery pack with the charger without bms? because the charger only goes to 58,8 v? Hope for anwser
Great video! I have a question, do you need to balance charge multiple lithium ion cells in a parallel configuration? If I'm using six 18650s in parallel, and I have all the positives and negatives connected together, do I have to charge the cells individually or can I charge them while still connected to the same rail?
Converted my weed eater to lithium battery 5 18650 cells in series total 18.5 volts. I use weed eater for approx. .5 of an hour to weed edges. My question is do I need a BMS and if not how long should I keep on the charger? The old NICD did not have a BMS either.
hi jehugarcia, i love your videos. Can you please guide me to one of your videos where you explain the charging circuit of your samba? ive build a 44,4v litium ion battery pack out of 18650 cells. i split the battery pack up in 4 rows with 11.1 volts, and i use a 12v Car battery charger to charge each invidiual rows! haha. so i never get full cells, I want to build a 50v charger. And i would like to see how you pulled it out. thank you.
I get it but what about people charging cells or cell packs like they were SLA batteries? Hard on them right? I mean is a different power curve all together.
Interesting, but confusing. Applications vary, for instance if I need a lot of power (50A @ 28V) for a very shout period of time (45 second), with a lot of time for trickle charging in between, can I get away from balancing. Or if I always trickle charge to a lower voltage can I get away from balancing? BTW it is a LiFePO4 battery pack.
I need to made a pack for electric skateboard, and I thing it's necessary 10S LIPO to do this. You find 2 a 6S to buy, never 10S, so for arrive to the 10S it's necessary combine the batteries offers in market.
JehuGarcia, just came upon your viseos; super work. I built an EV, but nvr used Lithium batts, I have a system with Solar & other Gens that recoup some energy while driving. How or what do you recommend be used since my battery bank receives continual charge as it drives. Question based on changing bank to a lithium bank such as your vehicle. Thank you for your time. Alex
Some years ago I installed an extra 4 kWh battery pack in my 2008 Toyota Prius, it consisted of two packs 24V of 6 LiFePO battery banks in series. The 48V was then converted into 200V and set parallel to the existing battery. After a couple of months the capacity dropped rapidly and the BMP kept moving charge from one cell to another. I decided to take the BMS completely out of the system and within two weeks the cells fully recovered and I got the full capacity back. The problem with a BMS is that it looks at voltage only, not charge.
Nice explanation, thanks for the video!
Clicked play, was interested, and a couple seconds later it had been 13 minutes.
Good video
atheist?
hentai nat Yep Yep
Bro, nice to meet you.
@ Michael Ramey, Exactly the same here.
Random question. LOL!!!
Been in electronics a looong time Best explanation I have heard. We are never too clever, or too old to learn.
Great explanation. Most people that complain and criticize never actually do what they are criticizing about. On the other hand, you are speaking from experience! Keep up the great videos!
jimginnyohio,
Thank you
@@bukolaayeni78 hello Baba, are you in the country? Can you join in a Powerwall project?
@@Cooldipo where is this going on? Interested
jimginnyohio, you explained beautifully, I own and operate a restaurant and thank God that I get very few comments coming from those kind.
Yay! Less cost of charging and alot less thinking involved in this aspect now. Very clear, thank you
Jehu, I love your style my friend and appreciate all that you do and teach. Great thing, please keep it up!
I didn't need the long-drawn-out and simplified explanation of why some batteries may need balancing while others do not... but you did such a magnificent job at it that I just continued listening for fun lol 😅👍
Goddamn crystal clear explanation, better than my university professor !!!
Haha I love how the video end with your high hopes for the drone to help storytelling and it crashes at first launch. I almost picked myself. Keep up the good work sir you are not only brilliant but entertaining at the same time
Hola jehu en el min 8:30 se muestra varios dispositivos electronicos. Me gustaria que dieras el nombre de cada uno. Gracias
Nicely explained and clearly stated. When most of us recycle all kinds of 18650 cells from old laptop batteries I'd bet most of us worry about charging and discharging them out of recommended voltage ranges. I just use two B6 chargers to manage the individual parallel banks so they are balanced. Since the cells vary wildly I never get them perfectly balanced but as you said, when they discharge at a rate of 2 amps each it doesn't matter.
EXCELLENT presentation, keep these good vids coming, very informative!
I finally got your point, Jehu. so it's not so much about perfectly matching cells, it's about designing the whole pack big enough that your discharge rate per cell stays below the discharge rate of the worst performing cell.
Now, how do you track that discharge rate cells, by the way ? do you write down how long it takes to discharge from 4.1V to 3.2V ?
I guess i can do this with the BTC3100 which tracks mAh and time elapsed during discharge (processing 4 cells separately at 1A "in parallel"). waddyathink ?
Thanks amigo.
Keep on trucking ! (from France)
I flew RC heli's with those sort of LIPO packs and many I knew didn't balance charge EVERY time; we would check the voltages of the individual cells, but often that was a cursory check done towards the end of charging, and /or as part of pre-flight. We would preach to new flyers to always balance charge, but that crowd often used the manufacturer's charger which charged thru the balancing leads anyways. However, we often didn't practice what we preached; there were many other factors far more important than balance charging.. In an ideal world, we'd balance charge every pack; but it takes longer, and always bleeds out some power doing so.
Great video, and e need some help here....
I have a electric scooter 48v/52v 18ah battery and the BMS died, can i remove the BMS, and start to cherge the pack by the thick positive and negative wires? Without the risk of explsion..? i only have a 42volt battery charger that i use in my electric scooters, lke Ninebot and Xiaomi... thanks on advance :)
When charging batteries to 100%, the cell balancing becomes most relevant since outliers will cause overcharging. If the overall regulator stops at 80-90% charging, the cell limits are not reached and balancers would not even activate. This also increases battery life to the greatest extent.
LiFePO4 Chemistry is far less sensitive to overcharging (at low currents) and incidentally is very efficient.
The absolute hands alltheway down college level clarity. U Rock !
I liked the video, I was curious though what did you use for short circuit/overloads for vehicle
This video is so incredibly smooth. Damn.
flip crashed that drone in the first attempt is so motivating!!!!. unlessit breaks something !!!!!! keep up
great video man, there was an article in march version of home power magazine that covered this very nicely, they took 48 cells all manufactured from the same place and on the same day, they then split them into 2 groups, they made packs of 4 cells. on 6 of the packs they installed a very commonly used universal battery balancer on them. then they left the other 6 un-balanced as a pack, then they ran them under loads using the same load over and over to simulate usage on the cells to use up the cycle life of the cells tell the capacity of the cells starts to drop. in the testing they found out that the cells that were hooked up to a battery balancer during its charge cycle reached its 1/2 cell capacity limit 37% faster than the cells left unbalanced, the theory behind this is that when the balancer is balancing the cells its applying a micro load the cell that needs balanced in the pack and when it does this the pack voltage drops and the charger sees this drop in voltage and starts charging the pack over and over tell the cell is considered balanced, these micro loads and charge cycles during the balancing phase takes micro portions off the cell cycle life over time, resulting in that cell wearing out quicker... the only benefit of balancing the pack is to get slightly longer pack life out of a single charge when in use... the more cells you have in a pack that spreads the amp draw reduces your need for balancing, because the cells will stay closer in voltage as the cell capacity increases on the same load over time..
Thats really interesting. Do you have a link to this article? I think for my off grid batter bank I will be going down the route of LiPo, Hobbyking has some great deals right now on some packs and I can build a 1.5kwh 48v ish pack for very cheap. My concern was balancing but I think I will go down the route of a Meanwell variable 1.5kw supply that I can vary by a microcontroller. This will monitor cell / pack voltage and give me complete control.
I have balance chargers already so no problem doing a balance charge every 10 cycles perhaps?
William link would be a plus and thank you
A link to this would be great
I appreciate the time you put in writing this . It really helps me , you are the best 💪🏽🎰
Entertained and highly informed.
I enjoy your relaxed, friendly and authoritative style. Makes me feel comfortable heeding what you say and confident to act upon your advice...
Thank you.
Another great video! Thanks for sharing.
Would you mind showing how you figure out what the weakest cell in a group is? Also, in a large pack (or maybe a small one?), is there a standard C rating per cell that you try to stay below during max charge/discharge current to ensure that all cells in the pack will charge evenly?
Unrelated, but I'd love to see a follow-up to your bottom-balancing video - one where you demonstrate the process and how it's done. :)
Great demo. Really shows the difference what a high load can do to a battery.
Delta in voltage grows as well when getting fully charged or discharged at 90% (I see it on the Winston 200Ah)
This is probably the most informational video I have seen yet on conceptualizing a battery pack for my electric vehicle. Thank you for clarifying many things. My vehicle is powered by two 500 watt, 48V hub motors. The current battery pack consists of 4 Sealed Lead Acid 12 volt batteries. Very heavy and doesn't deliver the range I need. My desire is to build a Life Po battery pack of 14s7p to provide me with 550-720 watt/hours of use. with 98 cells, I was confused about balancing vs. monitoring. Your explanation of power drain was very helpful. Since there is doubt in my mind about many of the Balancers ability to actually balance cells, I think I will stick with not having a BMS. It make further sense as I will not be requiring more than 20 amps of power at any time (most likely 10 amps steady), so the drain should be low compared to the capacity (below 2C if I am correct). Thanks again.
I just have a question I have build 60v battery pack 20ah with lishen cell 4000mah after 4 months start to get fully charge 66.7 in place off 67.2 are this can be need balancing or thats normal
Hi Jehu, I just joined yesterday and today I opened a battery froma dead laptop and found all 8 cells are in good shape. I made a small battery bank and my led lights are working on that. Thanks for your teaching. Question:- after putting 100 used 18650 cells in a powerwall how to see ballance charging and which battery is stop working aftyer few months?
No shenanigans just excellent information. I like your style, you are very smart. Awesome electric bus you got there too. Thanks
Professions are compartmentalized quite much so everything is a larger journey each time we dive in to a subject.
This was a helpful item you pointed out, it'll be useful to know the discharge rate of the lowest denominator battery in order to get an EV to run for longer. In student FSAE there is an endurance test which will benefit from this 🙂
Thank you JehuGarcia; this was a very helpful topic and you did an excellent job of explaining it. Btw; I like your T-shirt JAG35; nice graphics. Is it your creation?
May I know what the tiny device is called in 6:38? That shows cell values?
CellLog I got it!
Paolo Pabalinas not to be confused with Kellog
Another great tutorial ...and a good looking tele on that back wall that I can see.....
Great video and I learned a lot. So for a large Lipo4 battery for a deep cycle application like a sailboat house batter bank with long discharge cycles for the most part, although sometimes pulling a lot of amps for the inverter, would a bms be needed? What is the disadvantages of a bms? I mean why not put one on if it would protect the bank ? Thinking of going with lithium for my next boat, and interested in building my own system. Thanks.
+Bob Fomenko cost, complexity, and reliability, the cheap ones kill more batteries than they save and the good ones are expensive especially when you realize they are not essential
Good to know. Thanks for the reply.
This video is awesome. Thank you for the time and knowledge you put in to this!
I'm using thunder sky lifep04 3.2 60ah batteries in a 12v solar powered system for an RV. Would I need to balance these?
This is so cool. Great explanation using interesting but relevant side notes and visual
I want to make a 18650 li-ion pack for my old motorcycle, but idk if I need to do 3 cells or 4? And does it need to be balance charged?
I still need to check the voltage output of my '71 Honda CB350, but I need to upgrade the regular & rectifier to a newer combo unit first. But I'm just curious cuz I've seen lithium batteries on the market, specifically targeted for motorcycles, and they seem to be 4 cell packs with no charge circuit or BMS or anything at all. I just don't know if it would be ok to use one with a much older and less reliable motorcycle electrical system.
@jehugarcia if you don't use BMS, what is your methodology again in charging without one? I use a BMS but one time the BMS got busted and my LIFEPO4s got screwed.
great example demo. best I've seen
I wanted to ask you a question:
What do you think about charging a 52v 20ah Li-ion battery of an ebike without balancing?
my BMS died a couple of days ago and I am debating whether to get a replacement BMS. I know how important it is to stop before low voltages and can do that with a precise monitoring app. I still have my old charger that I was thinking to modify so that each cell gets a maximum 4.1v instead of 4.2v.
Thank you in advance for your help
I have one ? Is there a way to trickle charge my cordless drill battery’s during down time like months of not using them, I getting sick of buying battery packs because I forgot to keep them at 60 percent charge. I keep my motorcycle battery on a battery tender and it’s fine every year after sitting for the winter. Sorry to ramble on just getting frustrated with having to buy new battery’s for my cordless tools. Tools are lithium ion packs
jeh i need 624 lipo pouch 5000mah 100c bateries do you know where i can get them
I love you man , this video has the best explanation on youtube . You are the best 👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼👍🏼
There may be a risk that if even just one cell in a parallel bank develops a significant self-discharge current, it could cause that bank to reach 0% much sooner than the other banks? (and once the voltage plummets, the discharge current would then rapidly reverse charge the empty bank, killing it, even if it wasn't already damaged from the
Which is why the packs ( 7S ) I am building all cut out at 29.02 Volts. 7 X 4.145 with me charging them at 29 Volts max makes for cool LiPo batteries. At rest, they come in at 28.7 Volts which is 4.1 Volts per cell. Each pack of two parallel cells has a dual BMS board on the pack.
Tesla module from model s85, do i need some extra BMS or not? If yes, what do you suggest? Thanks
I have run my DIY powerwall for years with no balancing:) they stay balanced enough and every six months or so I'll manually balance them. Cells become unbalanced when you hit their limits all the time, I daily cycle my pack about 50% so lazy cells never get the chance to shift a pack.
Is it safe to use a 3V zener diode to protect a battery? The zener diode connected to gate of a MOSFET that controls the battery's output with a pull-down resistor of course.
A question. I want to power my Chauvet Slim Par 56 LED lights using 18650 Li Ion cells. The battery will be mounted on the outside bottom of the light instrument. My plan is to use 9 cells ... wiring 3 sets of three in series then connecting the 3 sets in parallel. May I ask your advice in wiring this battery and using the correct onboard (PCB) charger. Do I need to use balance wiring? I am hoping to get about 6 to 8 hours when fully charged. Thank you.....I love your videos/ Very informative.
Dang Jehu I just may have learned something and that is amazing . Thanks mon
I can't find a Cell Log 8 that is the same as you got there, are there others you recommend, maybe a video on some different types.
Is a 18V Li-ion power tool battery demanding enough to require balance charging? And or a battery management system?
Chingon, great info, got a grip of rechargeable packs, that won't charge. Now i have the knowledge of what shuts them down, balance of voltage, not heat or high ohms... 😮
As far as my understanding of batteries go, when you put batteries together they balance themselves take a fully charged battery and connect it to a used one, the full one transfers its energy to the used one until equilibrium is achieved
I would *NEVER* connect a fully charged battery to a discharged battery ...
Not in series, thats for sure. But if you do it in parallel they will balance each other out.
Excellent video, that's why you're "THE BOSS"
I made a parallel pack of five 18650 cells to run a small 3.5v lamp. I charged 4 of the cells individually to the exact same voltage and forgot to charge the fifth because I wasn't going to use any battery monitor for this pack. I solder all five cells together and leave it sitting there for about an hour. I remember I didn't charge the 5th cell so I disassemble the pack to charge that one cell. To my surprise all 5 cells were exact same voltage 4.1. I know that the 5th cell was 3.8v. I guess those 4 fully charged cells charged that last one to equal them all out.
You say you don't balance the cells, are you using a bms and letting that balance ? Or do you have some way of monitoring you battery health ? I'm looking at making my own pack and dont want to add in more expense or difficulty.
If you have covered this already could you please post a link to the video
Thanks
Still think the bt3100 doesn't check resistance?
This is pretty cool. So i’m doing this electric catamaran boat project which is going to have two 48v 6kw outboard motors which will draw a maximum of 13kw in total, and power will be coming from 4kw of solar panels and 75kw of tesla modules. I have been looking for the right BMS for these modules, but after seeing this video i’m not really sure i need any BMS in my system. What do you think?
2 @ 6 kilowatt motors = 250 AMPS, is a substantial load ! You need to verify how much the low-end cell voltage varies under load, and how much the high-end cell voltage varies when fast charging.
hello i have a question for you i just made a battery pack with brand new samsung35E 15s6p with bms . Now in case i wanna charge it without bms can i connect the charger (60v 7 ampere) directly to the discharge cable?
Thank you, that is really informative. Absolutely it's down to application. I'm off grid running solar. I'm over sizing my bank which basically means I don't need to worry about balance and also maximize cycle life as the bank will be charged to no more than 80% and discharge to 25-30% of capacity. Hopefully this might lead to the bank lasting as long as I do. If I need serious power or very long run time, I just ramp up charge voltage and accept deeper discharge cycle. Great video...
Max life = keep the battery temperature stable ...
Just charged my DIY 13s 4p 48v ebike battery I made without a BMS. This video gave me confidence to try it. Of course I monitored it's progress the entire time. Worked like a charm...Thanks for the info...
May i know the status of your bike sir without bms?
I'd totally make one of those lights if you posted a How To video. Great explanations!
+DrunkRamen coming
+FilmGelenk632 FilmGelenk632 yes
i have no idea what you are doing with your cells, if you are going to use 6000 of them to move a car around you have to balance them once them they will be fine for a few years
Does Tesla use any kind of BMS for each cell in their cars' batteries? Just curious.
DrunkRamen No sir, they dont.
You are a great teacher. Thank you.
Hi
Are batteries in M18 5A of Milwaukee impact gun, balance charging ?
Very good video. It's hard to find good information about this topic on the internet. It would also be nice to have an explanation about the difference between series and parallel connection in regards to charging. To my knowledge batteries connected in parallel are quite forgiving if you don't balance them, while batteries in series can be dangerous if not balanced (with high load).
Please make a video on diy spot welder
Jehu.....GREAT video , as always ! What year and style ( high windows/vents )is your V-Dub, Samba ?
Best explanation I've heard, good video
Can you elaborate on "staying below the threshold of the weakest cell" at 10:13 please bro, thanks.
If I want to replace the nimh battery used in my RC truck with 18650 cells, do I need to include a balance lead? Would you consider this application a high drain? Total volt need is 14.4.
+majesticreefs what's the amp draw?
30amp continuous on each motor, it has two. How do I wire the cells in parallel to max the capacity? The truck use two 7.2V NIMH 6 cell, the battery bay can hold 4 18650 cells on each side (total of 8 cells), I know how to connect it in series, not sure about parallel.
On your EV do you have a system to prevent over discharge & over charge of the whole pack? Interested if you are having to manually prevent these possibilities or if you put some sort of electronic control in.
Using no BMS with my solar systems lifepo4 batteries, just top balancers & cell meters for some low voltage protection. working great, going on two years now...
Unless they are being overcharged, deep cycled, or carrying huge loads, it's generally not necessary to monitor and balance all the time. Once they are all at the same potential, they will tend to stay that way -- until a cell starts to die, which is why one should periodically check the levels across the pack. Cars have an active BMS to do this because no human is supposed to ever see the batteries. (it has to be 100% automatic, 100% of the time.)
hola como esta.
queria saber cual pagina es de confianza para comprar baterías sony. si me puedes recomendar alguna
Hi can I use 10 laptop cells in parralel 14 in series 140 in total they are half 2000mah and half 2200mah but all together so they will be 50 amps continuous 5a per cell can I use a 45 a bms with this pack it is only 5 a out will this be ok on a ebike
.so if i take two lithium ION batteries in series how much voltage i should give them to charging them ? if i give 8.4 volt for charging is it will be enough ?
Yes it will be enough. However, charging them to 8.2V is much better for cycle life, and you'll be getting about 50% of cycle life.
Made 2 18650 battery packs. A 4s7p and 3s1p. Charged 4s7p using a 30v output connected to a buck charger. I set buck to 15.8 volts and limited current to 1 amp. On the 3s1p I used a 12v output adapter that plugs into 120v. On both, the BMS had an output and a charge input connection. I connected both to the BMS charge input to charge. The batteries worked great. But when I tried to charge the second time the charge wires got hot. On examination I found all batteries measured .4v. Should I not use the BMS charge input and just use the BMS output connection to charge? Lost a lot of money. Any suggestions will be appreciated. Probably not the proper place to post this but didn’t know where else to go. You are obviously very knowledgeable and maybe you can help. Thanks so much for your videos.
Good explanation, so I could do a powerwall using the cell log 8, or two of them to check my packs periodically?
I think I remember you saying that you dont leave them connected because they ironically unbalance the packs over time?
Quite a few people are n ow advocating not using a BMS. Very interesting info.
I rewired a 2000 civic hybrid battery. Two cell packs together for a 17v system.
I been charging them with my old school RV charger.
No problems yet.
Set it up with regulator to make 12v.
Should I expect a issue.?
I use for led lighting so far. No high wats.
Hi thanks
1- Can this( DELL J1KND 48WH 11.1VOLT )laptop battery be used as a power bank (without open it)and charged without laptop?
2. If possible, which board is suitable?
3- What pins are for charger and discharge connection?
Please write an answer with Google translation into Persian I do not know english
I can not copy here and past on google translate
How to calculate the charging voltage and current for the cells that are connected in series?
Jehu, Forgive me for laughing out load at your expense. I watched this video and reached the end where you attempted to launch the drone from your driveway. I saw the thing power up and then flip over. And I thought...'Did I see what I thought I saw? Did one of the propellers launch by itself?' I rolled the video back about 10 seconds and hit play. YEP! A single propeller launched by itself before the drone flipped over. I'm sorry Bubba...but I almost rolled out of my chair because I was laughing so hard!!!
I've watch several of your videos since discovering you a few months ago. I have picked up a lot of information from you and your videos. It is great information. I eventually want to build a battery-backup system for my home. But first, I want to build a portable but fairly powerful battery backup system that can run a few decently sized appliances. I am thinking about solar power, and have been watching DIY Solar Power with Will Prowse. Between the 2 of you, I don't think I can go wrong. You both provide insight about power storage from two different perspectives, and it is invaluable.
Keep on doing what you are doing Jehu!
Hi i have build a 14s 6 battery 18650, can i charge my battery pack with the charger without bms? because the charger only goes to 58,8 v? Hope for anwser
Great video! I have a question, do you need to balance charge multiple lithium ion cells in a parallel configuration? If I'm using six 18650s in parallel, and I have all the positives and negatives connected together, do I have to charge the cells individually or can I charge them while still connected to the same rail?
both, paralleled cells become one larger cell
Converted my weed eater to lithium battery 5 18650 cells in series total 18.5 volts. I use weed eater for approx. .5 of an hour to weed edges. My question is do I need a BMS and if not how long should I keep on the charger? The old NICD did not have a BMS either.
hi jehugarcia, i love your videos. Can you please guide me to one of your videos where you explain the charging circuit of your samba? ive build a 44,4v litium ion battery pack out of 18650 cells. i split the battery pack up in 4 rows with 11.1 volts, and i use a 12v Car battery charger to charge each invidiual rows! haha. so i never get full cells, I want to build a 50v charger. And i would like to see how you pulled it out. thank you.
Thanks for the practical demonstration. It helped me to understand it better.
Interesting.. what sort of discharge rates do you use in your electric car?
hello jehugarcia can you talk about LTO battery. any info would be great
Great demonstration. Love your channel.
I get it but what about people charging cells or cell packs like they were SLA batteries? Hard on them right? I mean is a different power curve all together.
I learned something new thank you very much.
Thank you my friend excellent exclamation really cool video liked and subbed kind regards from the UK 🇬🇧👌🏼
Interesting, but confusing. Applications vary, for instance if I need a lot of power (50A @ 28V) for a very shout period of time (45 second), with a lot of time for trickle charging in between, can I get away from balancing. Or if I always trickle charge to a lower voltage can I get away from balancing? BTW it is a LiFePO4 battery pack.
experience is what matters most. thanks !
His RND lab is a break through because of his passion. And very valuable knowledge giving it free thanks to him.
Garcia, great explanation man! I have a doubt, if u can help me: I need create a 10 s LIPO batteries, how to combine all?
i'll need more datails than that
I need to made a pack for electric skateboard, and I thing it's necessary 10S LIPO to do this. You find 2 a 6S to buy, never 10S, so for arrive to the 10S it's necessary combine the batteries offers in market.
+Zama use 2 packs in series, there at 5s packs there also 6s and 4s there should be a few ways to get to 10s
JehuGarcia, just came upon your viseos; super work. I built an EV, but nvr used Lithium batts, I have a system with Solar & other Gens that recoup some energy while driving. How or what do you recommend be used since my battery bank receives continual charge as it drives. Question based on changing bank to a lithium bank such as your vehicle. Thank you for your time. Alex
+Alexander Robles Tesla packs are the best in my opinion j35.us/eBay-Tesla-Modules
What are his batteries that don't need to be balanced called?