Lifepo4 Basics and What You Need to Know!
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- เผยแพร่เมื่อ 27 มี.ค. 2021
- This video (I hope) covers most of the main need-to-know info on lifepo4 cells, as well as some suggestions for extending the life of your cells. Towards the end, I cover an aspect of cell safety that I think relatively few touch on.
(Affilate Links Below)
Battery Cells:
1. s.click.aliexpress.com/e/_A5znrE (lishen)
2. s.click.aliexpress.com/e/_9HFYlE (lishen)
3. s.click.aliexpress.com/e/_A74Zvm (eve)
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Thanks for always imparting with simplicity
Great video and you answered so many questions i had on Lifepo-4 batteries. I have used led acid batteries for years to power my Ham Radios and recently purchased a Lifepo-4 20A 12V as a backup so i know charging and discharging are different so i am having to do research and you have helped a lot as this is all new to me.👍
Nice summarization of lifepo4 battery characteristics! I'm still waiting for my Lishens to show up from China. In the meantime, I've been researching and gathering tools and materials. Your channel has been a good resource. Many thanks!
Glad I could be of help. One of my shipments took over two months, and then the next one came in early (barely 4 weeks). Good luck with yours.
Did you get the batteries from China?
I like the simple straight up on this infermation!
Thanks Will, that was a great presentation
Thanks for this info, i have been trying to find the men/max voltage for my new lipo-4 battery
Comprehensive and informative. Thanks.
Nice safety points man, I bought a 12v LifePo4 Valence battery, it has a built in BMS, it's a 40Ah battery so I am trying to turn it into a solar charging power station with a decent 1000w pure sine wave inverter for emergencies and on the go as well. Thanks for sharing your knowledge man, cheers.
Thank you so much for these basic, yet extremely important information!
Excellent, informative video. My batteries are in route from China now. I have to set the video playback to a slightly slower speed so I can take notes. This guy speaks just a little too fast for my 66 year old brain.
I just recently educated myself for solar AGM systems, now this is a more complex system, but seems much better, if correctly done.
Did you buy the cells from our EEL Battery?
@@eelbatteryofficial no
Great video - thanks!
Very well done you reinforced what I already knew but one thing I do a little different is that I charge once a week to 13.8 seems to bring cells nicely in balance.
That definitely works! They should stay in balance for much longer for a week though, so you shouldn't have to do it so much.
Amazing video. I'm subscribing!
I will see after top balancing but all of my batteries read 3.280 except one that is 3.200..... when arrived. thanks for the great video.
This was helpful. Thanks!
Thank you for addressing the casing as carrying the positive charge! I saw one guy using a Phenolic Sheet of plastic as a smart heat resistant cell separator and loved that idea and would like to retrofit mine. For compression I used 4mm OD 20mm Long Spiral Stamping Extra Heavy Load Compression Mould Die Springs. Set of 10 cost me less than $10.
That is a great idea - I might be stealing that. Do you have a link for the springs? I would love to see some pictures (my email is in my about tab).
I have a photo of the end of mine. Using 5/16" steel easy rod (threaded rod) from Lowe's but can't seem to attach it.
Positive or negative casings pose the same risks as each other , polarity doesnt change the result of a fault current path
learnt a lot here, thanks
thanks very much nice video
For winter time to avoid battery getting too cold, I use the Facon 7-1/4"x25" RV Water Holding Tank Heater Pad, 12Volts DC under my battery (8s) Lishen 272AH array and a 24/12v buck converter to power it and other 12v circuits.
Q: What do y'all recommend for COOLING, your batteries in a shed? My summers get over 100°F and I want more than some fans. Am leaning towards Peltier cooling.
for as much power as a peltier setup would take, what about a small window a/c unit? if you set it almost as high as it would go, just to keep things from getting TOO hot it might work ok
Top Video 😊👍 Lifepo4
Ty
thank you sir. very informative.... I am a radio amateur and building a pack for emergency and portable use. Unlikely to use solar in Seattle area.... I am using a Daly bms and will be 4 VariCore 3.2V 90Ah LiFePO4 batteries. Walk through of going from batteries to working pack would be great. I will follow your top ballance procedure after I watch it.
Thanks for the comment. I think I've basically covered everything you need to get the batteries going, thought not in one video.
Hey Mr. Will enjoyed ur vid! Ive been building only few months now but ive come to realize balancing is very helpful saving the bms from overworking or faulting during charging by eliminating a high or low cell from shutting bms down. when building 100-310 ah cells the .025ma bleed resistor would take 12,000 bms cycles to adjust a unbalanced cell config if unbalanced(Lol) do the math? but more important is that cells are matched as close as humanly possible bcos my issue lately is China sending unmatched cells making battery capacity suck! not just voltage but impedance too and electrolyte weight too! Ive been building with 5amp active cell equalizers and this is the bomb! with big cells important to get the 5-6amp units the ones with the little capacitors because they work awesome and maintain balance from bottom to top! Although pricey @ 15$ 4s, 30$ 8s & 55$ 16s they eliminate all this timely bottom n top balancing! My builds now use a 500amp relay kilovac EV200AAANA with built in coil economizer uses 1.7w hold and drive it with a daly 20-40amp bms for safety/control purpose and let balancer do all the balancing! I have 20$ in dalys Bms+ 15$ in equalizer n 30$ in relay so 65$ gives me 500amp BMS system that can run 200-250 amps w/no heat or current bottle-necking MosFets and it's bullet proof!
Thanks for sharing your video rocks!
Awesome info, thanks for sharing your experience. If I have too much difficulty I may look into cell balancers myself, but a good balance should limit the need for this.
Great video thank you! GOD BLESS!
great series one question what size height/width /thickness are they I would like to build the the compression case while I am waiting for them thank you for your time joe
I have another video where I go over that!
Great video, like the 80% rule. Confirms with what I've heard about prolonging battery life. Do you recommend putting thin two sided foam tape at four corners to reduce rubbing also? I've seen it done to keep them from rubbing in a trailer but not sure how it effects compression? If i stick to the 80% rule it shouldn't swell I'd think.
Shoulda watched to the end, you do recommend keeping them from rubbing with something lol.
Hi TheWilltoBuild, is there any difference in long life cycle life if I make a 12v battery out of 4 cells of these eve vs hundreds of small 18650 batteries? Since these are new, I wonder if 18650 batteries have better quality or it's the same since both are lifepo4 cells anyway?
Thanks btw for the tips and the great info.
Good question. I don't actually know which one will last longer, an individual prismatic versus cylindrical cell. What I will say is if you build a cell out of many 18650s, it should last a long time, because if one dies, the other cells will compensate, so it isn't sensitive to one cell dying. That said, it is way more trouble to make a battery out of 18650s than prismatic cells, and probably more expensive.
Would you not need to set the solar as bms should shout everything down?
I'm replacing lead acid with lifepo4 in my mobile scooter 48volt, any suggestions
Yes.👍 LiFePo4 battery 🔋
Question - I just put together my first ever 12v 4s LiFpo4 100Ah battery pack a week ago, but right after I finished the top balance, I accidentally arced one of my cells. My concern is, how much damage do you think I did even though it was a quick arc and do you think that cell will stay in balance with the others over the long run? Thanks again, and keep up the great videos.
I doubt a quick arc is a big deal. Check the voltage of the cell in comparison to others. If it is very close or identical, you're probably in good shape. If not, maybe top balance them again?
The temp sensor inside the bettery will prevent the battery from being charged too cold ?
There is no temperature sensor inside the battery. The only thing that will stop it from charging when it is too cold is you. You can do that with a BMS which has cold temperature protection.
Hi very informative just a question, I live in South Africa and planning on building a panel van camper next year, I'm planning on going to desert and semi desert areas, the temperature can range from 0 to 50 degrees Celsius in a day, have you got any advice on how to keep my batteries from getting damaged
Mostly I would try to insulate them. If they are well insulated and aren't in high or low temperatures for too long (a few hours) you should be fine. If the temp is going to be near zero or near 50 for extended periods of time, you'll want to try to think of some sort of climate control. That could be as simple as some heating pads or fans, or something more sophisticated, depending on how long they will be exposed to those temps.
Thanks a lot most of the usage will be at the upper 40 to 50 degree, I'll have to see if fans will work thanks 👍
Thank you for the informative information I have the same cells 280 ah and when I hooked up my charger the same one you have the white one I get a spark, my cells are at 3.3, V I have a BMS is this going to harm my cells? I notice your charger is turned on when hooked up mine is turned off when hooked up.
I'm not sure what caused the spark, but sparks are not uncommon when you are hooking up things that have a capacitor in them - for example an inverter. As long as the voltages are normal, I think you are fine.
In the future though - always make sure to disconnect the charger when turning it on, off, or adjusting it's settings. That means turn it on - then connect it to your batteries. When you turn it off - first disconnect the batteries - then turn it off.
Pre charge your capacitors with a resistor first, that'll take care of the spark. And attach conductors to the inverter first, then attach to battery.
Thanks. I wonder if one was to do all these good practices what is the value of this chemistry vs another chemistry. I am investing in this form factor and chemistry currently. Should other chemistries be considered when taking into account these optimization strategies? Are the differences small enough to make the choice a matter of personal preference? I understand my questions are subject to qualifying use applications and considerations unique to the user. As a metaphor, steam engines are superior until you factor the good practices required not get blown up and worn down by maintaining the system.
Great question. Lifepo4 is definitely the battery wall, large storage chemistry of choice right now. It is comparatively cheaper, safer and easier to use than most other chemistries. There are Lipo cells that have better energy density, but they tend to be more expensive and more dangerous. There are also lithium titanate cells which can be charged and discharged at really high and low temperatures, and at really high rates, but they are very expensive. So lifepo4 is definitely the best large storage option unless you have unique circumstances like extreme temperatures (like below freezing) or need really high charge/discharge rates.
Hello everyone.I have batteries eve 280A/H from Docan Tech. What is the stud torque for these batteries. Thanks
Can't believe the case is not isolated from the terminals of the cells! If it was going to be any potential then surely it makes sense to be -ve!
Do you think there's a need to do a capacity test on EACH individual cell in my 280Ah 12v config? I'm currently top balancing them and still haven't found a consensus on the question. I'm definitely going to do a test on the whole battery once I assemble it with BMS.
Good question. It's simple. Create the entire 12v battery and test that. If the entire battery has 280 Ah, then every cell in the battery must have at least 280 ah. If the full battery doesn't meet 280 ah capacity, then at least one cell must have less than 280 ah, in which case you need to test the individual cells to see which ones are below capacity. So basically, test the full battery and if it doesn't meet capacity then and only then do you need to bother testing individual cells.
@@TheWilltoBuild Thanks! Makes perfect sense! Now if only this top balancing would just end already! Down to 0.150A 😂
@@Mike_219 No problem. Also, the current will never go down to zero for the top balance. Make sure to take off the charger periodically, let the cells rest for a few minutes, and check the voltage of each cell. When they get to what you want you will be done. If you wait for the current to go to zero then you'll wait forever.
A nice PDF with this information would be VERY HELPFUL!
I made a battery pack of 16s 105ah . With Ant bms . The problem with the battery pack is it is not getting balanced. Should I buy a bms with balance option?
Did you top balance first? Most BMS balance options are really, really slow. If you haven't balanced your cells, definitely do that first. Otherwise, there are active battery balancers out there I would look into. I don't think most BMS can do much in terms of balancing for larger cells.
@@TheWilltoBuild please share the link to purchase active balancers. 3.2volt 16s 105ah.
I have a EVE 280A .. What is the highest and lowest voltage good for charging and discharging at 80% , 85% , 90% , 100% use ?
Check this link out: diysolarforum.com/resources/general-lifepo4-lfp-voltage-to-soc-charts-tables-12-24-48v.109/
did you do a solar charge controller setting video, ie a cc that had lead acid in mind when made, for lifepo4
Will be doing that soon, I promise.
@@TheWilltoBuild thanks in advance
Hello is it okay to top balance cell 4 cell, parallel 2 cell at a time ? and another 2 after, because i only have 3 busbar but i need atleast 6 busbar to parallel all 4 cell at the same time. thanks
It should be ok, but I would make sure they are all very close or identical in voltage. I would also take time to a higher voltage to be sure, at least 3.5v.
hey Panther you can always make temporary buss outta any copper wire ie: 14ga would be fine bcos voltage is so close when balancing that current and heat loss is not an issue!
Use copper pipe, flattened, for busbars.
Nice video. I am new to this concept. Some people have recommended to me to go with a 48-volt system. Here in Southwest Florida, it gets warm. We keep the thermostat at 81* all summer. Mainly to keep the power bill lower. And yet, last July we used 1440 kWh. That is why I am looking into other ways to get my power. What do you think?
The higher the voltage of your system, the better. You'll need smaller wires, and the efficiency of the system will be greater. Go for 48v if you can. Given your usage, and assuming 5 hours of sunlight a day, you need a 10kw sized array to generate that kind of power. That is big, but not huge - just a large home system. Sounds doable to me. If you want to run entirely on battery though you'll need a big battery system.
@@TheWilltoBuild I was thinking about running a PMG with a small AC motor. Generator big enough to run my home and the motor.
I looked at the EVE 280 specifications, the updated one saying that you can get more cycles if you compress the cells, and it looks like they did extrapolations from fairly limited tests. Maybe just 800 cycles. They use a linear extrapolation for the uncompressed data and a nonlinear one for the compressed data. And the actual data shows that at 800 cycles the uncompressed cell is better off, with 96% capacity vs. 93% for the compressed cell. Is there another set of data out there that more clearly shows capacity vs cycles with and without compression? If not then it looks like lots of people have jumped to the wrong conclusion.
Really interesting point you're making here. The EVE datasheet I am looking at has uncompressed at 94% at 800, versus 93% for the compressed, so basically identical. I don't actually have any other datasets to lean on the back up the importance of compression other than the manufacturer's suggestions. I think the importance of compression is already overemphasized on most DIY forums, and you bring up a really good point concerning the evidence it stands on. This is especially true considering the fact that if you cycle once a day 2000 cycles is already five and a half years, in which case battery prices will have come down and technology significantly increased by the time you see any real degradation in your cells. I will definitely keep an eye out for more information on this.
@@TheWilltoBuild Of course what I would really like to see is capacity vs cycles for a more realistic profile. Maybe 3.33V to 3.15V with 0.5C discharge and 0.2C charge rates. Those voltages at those rates should be around 99% to 10% capacity. I bet it lasts a really long time, with or without compression.
@@willdejong7763 Couldn't agree more. I think using them without full charge/discharge, say middle 80% under reasonable temperature assumptions, and they should last a long time and compression is unlikely to make a significant difference.
Will Prowse said in one of his videos that if you set your charge discharge parameters to not max out your battery they will probably last foe 10,000 cycles. I have read 4,000-6,000, so by not maxing you can almost double the cycles it seems. I personally could have probably gotten away with 4 cells, but since that would have meant getting the most out of them when they went down to 8 280ah 3.2 cells for 800 bucks i bought 8. Now i have to figure out what parameters to set them at to baby them, hopefully i will never have to buy more.
@@TheWilltoBuild There are already three or four other types of chemistry about ready to overtake lithium ion batteries stay tuned!
Could you please speak to stacking batteries sideways upside down things like that for different configurations for solar. Meaning can you lay them sideways and stack them? Or do they always have to be standing up like a regular battery? And nobody has really addressed if these batteries are safe to be inside your house rather than outside like let acid
Good question. I've heard different things, but I personally would not put these cells on their side, I would only ever put the standing up. Others had said otherwise, but I just don't think that is the way to go.
As for storing them in your house, they should be perfectly safe unless there is a leak. If the cells swell for some reason and electrolyte leaks, that stuff is really toxic and bad for you. So I think they are probably safe to have in your home, but I would have them in a plastic container or something so that if the worst does happen, and they do leak, everything is contained.
i just got mine what kind of charger, balancer would you recommend.thanks for the info
I've got a video on the cheapest way to charge/balance them. But if you willing to pay a little, there are alot of great charging option available. I don't have them though so I can't recommend any specific one.
RIGHT!
Alot of BMSs tend to have an over charge voltage of 3.75 +/- 0.05 per cell. Whats your view on this?
I think that is just too high. Charging all the way to 3.65v is already not good for your cells. Taking them to 3.75 likely won't kill them, but it really can't be good either. A proper lifepo4 BMS will cut charge at 3.65 (or let you customize it yourself). I would say get one of those.
Indeed I would tend to see things that way too. I am trying out an Overkill Solar 16s BMS as we speak and it is very customisable!
I do have these batteries for my own project. I assembled 8 80ah to form a 24v system for my electric pallet jack. Little do I know that unless you put loads into the cells you’ll never know if the cells are bad! Lucky I put a BMS in it with Bluetooth connection with my phone so that I can monitor the real time data from the cells. 3 of the cells do fluctuate from 3.9v to 2.2v whenever I operate the jack. That triggered a lots of errors and the BMS automatically cutoff a few times. I bought it from Taobao and Taobao, you know........ without the BMS I think I’ll never be able to tackle the problem.
well, if they lifepo4 they should never read 3.9v - that means they are over charged. Voltage definitely dips under load though - what kind of load are you putting on them?
@@TheWilltoBuild 30-80amps were observed with load. With one particular cell, it triggers 164 over voltage alerts within 10 mins test
@@bennyyeung2172 Hmm, they should be able to handle 80 amps. My *guess* is that either the cells were bad to begin with, or they were overcharged and damaged (again, they should never be 3.9v).
can you comment on Grade A vs Grade B...does it really matter for energy storage ( not ebikes)
brilliant video. could someone tell me what setting I would need for my epever solar controller to cycle between 10% and 90% on my cells? these are my current setting....
Over Voltage Disconnect 14.7 V
Charging Limit Voltage 14.6 V
Over Voltage Reconnect 14.6 V
Equalize Charging Voltage shut off or 14.4 V
Boost Charging Voltage 14.6 V
Float Charging Voltage 13.6 V
Boost Reconnect 13.3 V
Low Voltage Reconnect 10
Under Voltage Warning Reconnect Voltage 11.5
Under Voltage Warning 11.5
Low Voltage Disconnect 11.0
Discharging Limit Voltage 10.5
Equalize Duration 0 or set as low as possible
Boost Duration 180 minutes
Thank you for pointing out that the cases are positive! I have not seen that mentioned by anyone else, and it is definitely a safety hazard to be considered. If one bare case comes into contact with its neighbor in a pack, really bad things are going to happen! I can envision that happening in a mobile installation where the cells are able to abrade, even a little, against one another. I intend to place thin sheets of polycarbonate (Lexan) between the cells. And, if the cells were going into a metal battery box, on the sides and bottom.
I am in the middle of wireing this exact setup with two bms. But I cant figure out how to wire the bmstwo bms. The B- goes to battery the c- comes out as the main -. If I'm trying to parallel them would I wire from one c- to the other bms c-.
There are two types of BMS, separate port and common port. It sounds like you have separate port, but maybe not? Separate port has three cables, one to connect to the battery, and one to connect to charge the battery, and one to connect to draw from the battery. Common port means that the charge and draw (or load) are just combined to one wire.
For a common port, think of the BMS like this - the BMS attaches to the negative of your battery, and then it has another wire (or two if it is a separate port) and this is the negative wire that you use to draw power from the battery (along with the positive terminal). So think of that wire from the BMS (the one not attached to battery negative) as functional battery negative. So to parallel two batteries together, you would simply connect the positive terminals and connect the "extra" wires from the BMS - which are the function battery negatives.
The BMS works by standing between the power draw/charge and the negative terminal of the battery. So make sure that whatever is charging/drawing from the battery has to go through the BMS to get there - that way the BMS can disconnect that charging/drawing if need be. Google is your friend here, I'm sure there is a good wiring diagram somewhere, but this is simple, even if it doesn't seem it. Treat the two batteries as separate batteries. Where ever you would hook up your inverter to the batteries w/ the bms, that is where they should be wired together for parallel.
@@TheWilltoBuild I have a common port. I just see pictures of inline parallel where you connect one battery to another and then pull from the positive and negative terminal from the main battery. But I know you should connect them together and pull from positive from one and negative from the other while they are connected. So If I connect both bms outputs to the same post. And connect the banks in parallel and pull a main positive is this correct?
@@partyfoulIguess Ok, arrange the cells as two separate batteries. Wire them two BMSs to them as two separate batteries. Then connect the two battery positives - that is you main positive and you connect the positive of your load to that. Then, connect the P- or C- both of the BMSs (whatever you BMS has labelled, mine is P- but yours may be C-) together. That is your main negative. Connect your load negatives to that. Then, you are done.
If I order 280ah cells from China and they all come with the same voltage. Is it mandatory I top balance them? Or can I just hook them in series and build my 72 volt pack?
I wouldn't say it is mandatory, but it is definitely advisable to balance them. There is a real chance they aren't at the same charge level, even if their voltages are similar, given that the Lifepo4 charge curve is so flat. Really up to you though. If you are using a BMS then the main risk is just that you'll get less capacity out of them than you otherwise would.
@@TheWilltoBuild thank you,
I am in the middle of top balancing 8 x 280Ah cells. I am going to make a large 12v 560Ah battery. It would be good to see you making one so I don't make a mistake
Also a great idea, which I will definitely do soon.
Hey Mike I will be doing the same thing. Mine are on their way from China, expected to get them around the end of the month. Would like to know how things are working for you.
Any recomendations on a smart bms I use daly for temp controlled enviroment and as a fail safe.but in my RV going to go with solar overkill on first pack and see how I like them
I need to do more BMS research. I'm using a Daly smart for my system, and I like it, but I need to put it through its paces and do a full review. I've heard good things about the overkill.
I currently use a Batrium BMS, but got my hands on the diyBMS by Stuart Pittaway, the latest Controller 4.2 and the new boards 4.4 are nice. He’s working on a shunt as we speak. Check them out. Fairly cheap and also check out the Facebook group on diyBMS
@@TheWilltoBuild what model Daly did you buy... The 16s 250 A for about $230? Btw I ordered a Genetry unit. Apparently one of the last 5 on the shipment. Hope it's good!
@@allmomomosthomebus3895 also OverKill Solar BMS are also great with a warranty here in the USA
032921/0429h PST 🇺🇸. Please note “ Overkill” is only a seller. A very high priced seller. The real name of the BMS is JBD, not Overkill ! The cost of 100A JBD smart BMS costs only US$55~60 each inclusive of shipping. (US specific) I use JBD on 3 of my PV Systems and they perform perfectly. The Bluetooth range is almost 60’ and satisfactory. You may be able to extend the range by soldering 1.5 meter AWG20 or 24 at the tip of the internal antenna on the BT dongle.
It’s also possible to configure the Battery charge parameters on iOS/ OS X , Android & Windows systems. A one time fee of US$5.99 is required to obtain the software for iOS/OS X devices from Apple App Store. I’m not familiar with Android/ Windows system downloads. Renaming individual JBD BMS is possible to identify each set of PV system, being used. Monitoring PV System on Apple devices are easy and effortless. I’d highly recommend JBD BMS for PV systems. Good luck and 73s...
Electrician here just a comment on the last point you touched on, should you be touching a terminal and the casing depending on which cell you are touching the potential is going to be between max 3.5v to 48v dependant upon the amount of cells connected in series , creating a pathway through your body by contacting the unprotected casing and a terminal will in the worst case (48v)be a minor ouch moment and more likely due to skin having a very high electrical resistance value ,voltages under 24v are barely felt , so no , physically shorting the case and a terminal would create such a small current pathway if any , its not a concern .. something with a much lower resistance value , ie anything metal touching the bare casing and a terminal would create a serious fault current which if nearby could result in a flash burn and lead to a run away .. oh btw it would make no difference if the cases were positive or negative , the same potential exists only the polarity changes
This is a good point. Direct contact with your skin isn't going to do much, but shorting with a metal tool or with busbars can create a massive discharge that could easily start a fire, shoot sparks, etc. I probably should've gone into this more in the video, but at the time I was worried about confusing people, and I didn't want anyone getting cavalier with their batteries because the voltages were low. Given their capacity, a short circuit could an huge problem.
50VDC is enough to do harm to humans. The high amperage capacity of batteries is what makes them dangerous.
This is why most countries have introduced regulations on 50VDC work.
Hi I am buying 8 of the 200ah cells with 4 100watt solar panels a 4s 12v 120 bms a Victron 100/30 charge control and a go-power 1500 watts inverter. Do you think everything is OK or is there anything I should change. It is going to supply 110v in my house in the Cape Verede Island. Thank for any advise.
I can't advise without more details. Make sure you wire your solar panels correctly - you need to make sure your voltage and amperage will not be too high for the charge controller. I will also say that 400 watts of solar power, assuming 5 hours of sunlight a day, is 2kw of power. But your cells have a capacity of 5kw, so on an average day you can only charge your cells around 50%. There are many other factors to consider, but those are the things that pop out to me.
@@TheWilltoBuild I will be wiring the solar panel in series which will give me 80V with 5Amps. So should I buy 6 solar panel and connect the panels in Parallel which will give me 20V and 30Amps??
@@napoleonbarros8272 You could, if you had six panels, do two string of three and then wire them in parallel, so that would be 10 amps at 60v. That is how I would do it. All you need to do is wire three panels in series, wire the other three panels in series, and then put those two sets of three parallel together. I would do some more research on strings vs parallel and solar panels, there is alot of good information out there on this topic.
Ok but I can still use the same BMS 4s 12v 120a?
battery 24v 100ah Lifepo4, charger 20 amperes is it normal or is it very amperes?
The volum level is to low on the audio, I'm in a garage with some noice using airdots, I can not hear you ...
can you tell us the the voltage and temperature range, i missed the part where you told us.
Voltage is always between 2.5 and 3.65. Temperature is a little more complicated but it is best to keep them between 32 F (0 C) and 100 F (37 F).
I found a great deal on some large nmc cells they are near 250ah They have a good power to weight ratio - I need them for my EV conversion - My question is what difference does it make if I use more smaller batteries or less of the giant ones? I recon that I will use 1/3 C 60% of the time 1 C would be pedal to the metal - there might be times when I go 50 miles an hour for 30 minutes and that would be 1 C - charging would be .2C There wont be any active cooling
Ahh, this is a complicated subject. I would love to do an EV conversion myself. I think many EVs go with small 18650 because they need to get to high voltages (Tesla motors run at 400v ish), so you need to put a lot of cells in series to get voltages that high. Additionally, smaller cells are easier to cool. But there is no doubt that larger, prismatic cells are more space efficient though - and I do know some of the other EVs out there do not use 18650 cells and instead use other formats. I think which cells you will use will depend on many factors, but I think EV motors generally need quite high voltage so I would think it might be hard to get those voltages if you are using really massive cells. For example a 96 volt system might take nearly 30 NMC batteries, and 90 volts is not alot for EVs. So basically, I think there are many, many factors to consider here.
@@TheWilltoBuild Thanks for the reply - My car is very light only 1750 lbs (800kg) it has a 5 speed gear box so I can chose the gear that least stresses the motor. The motor is a 96 volt motor that draws a rated 190 amps - my 28 cells x 3.7 volts = more than 96 so I got the volts and - hopefully I have more than enough amps
One question😅can you run a small 220v fridge(with around 1 or 2 amps of current so around 300 to 500 watts) with a 12v(8 lifepo batteries connected in parallel with an overall capacity of around 6kw)? What kind of converter should I use?😁
Let's do the math. Let's assume 2 amps at 220, so 440 watts. 440w/12v is 36 amps, so if your battery cells have a capacity greater than 36 ah, then you should be fine even if you only did one 12v battery and not two in parallel. You'll need a 220/12v inverter, i.e., an inverter that takes in 12v DC power and converts it to 220 volt AC power (typically at 50 Hz) if you are outside the US.
@@TheWilltoBuild well my fridge uses dc input cable, are there dc to dc inverters which does the job?
@@TheWilltoBuild I tried to search for inverters/transformers but some just misleading(at least I felt like it cuz it's too good to be true based on their sizes) and especially if they are from the big red flag on our northwest(I'm from southeast asia btw so..)
@@TheWilltoBuild btw, thanks for the fast and sensible replies😁👍keep up the good work
@@marcangelodonelo5656 Your fridge runs on 220 DC power? There are DC to DC converts but I don't know of one that can handle that step up in voltage. You may want to run an 8s 24v system, that would be more efficient at getting to 220.
I have experimented with my lifepo4 and have recovered cells at 1 v and had cells go to 4.3v. It was a garbage pack but there was no problems .
That is really interesting to hear. Did the capacity take a hit?
@@TheWilltoBuild it was a bad pack to begin with. I would guess the capacity to be 60% anyway. Just for science.
Making my first battery pack using 3.2v 100ah 1c lifepo battery for an ev. using 30s bms. guide me. i have very less knowledge about the safety.
i use 24 6 volt deep cycle set up to 48 volt . my shed temp is - 24 below to 120 deg. don't think these would work for me.
Hi...if I understand right what you are saying is that if I keep voltage between 90% max and 10% min I can drain @0.2C all the energy every single time to the 10% voltage and still get the 3500/4000 cycles they should last....
I can't promise that, but I think that would significant increase the probability the batteries last that long. Always keep the batteries charged between 90% and 10% and don't charge/discharge to heavily (.2 is great, even up to .5 is ok).
@@TheWilltoBuild so if 2 or 3 times a year I am without sun for an extended period of time and can’t charge the batteries/cells and I use all the capacity of the bank but keeping the voltage value at least at 10% of its minimum voltage value I won’t kill them...
Yeah I think so. A couple days at 10$ capacity is no big deal.
Where can I get instructions or Do you have instructions on how to build
84V 50Ah lithium iron phosphate battery pack for my E-Bike?
I'm using EVE 280 Ah cells in a 48 volt configuration and charging them with solar panels. So it looks like if I want to charge them to 90%, the charge controller should be set to 53.6? What about float?
I'm thinking I will discuss that in another video, but here is a good resource: www.solacity.com/how-to-keep-lifepo4-lithium-ion-batteries-happy/
I would recommend following Will Prowse's recs here: diysolarforum.com/threads/recommended-charge-profile-for-diy-lifepo4-batteries-sticky-post.5101/
Specifically, my params would be:
Absorption: 56.4V
Float: 54V
Inverter Cut-off: 48V
Basically, NEVER use the equalize charge function (or set the equalize value so low it never comes into effect), and float can be set below your max voltage so it isn't used.
Your math seems way off. For 4 cell bank the charging voltage should be 14.6v for 100%, so 90% should be somewhere around 14.4 etc. So multiply 14.4 by 4 to get your 48v configuration would be 57.6. so I have no idea how you calculated such a low voltage, unless my math is way off
Also lifepo4 isn't supposed to have a float charge but if your charger must do it than I think it's somewhere around 13.8v or less. Do some research on it
@@eksine Nope, 90% is around 13.4V according to a reliable source. 14.4 is still above 99% soc.
@@SpeakerKevin Yep, 90% is about 3.35v per cell.
My batteries arrived somewhat wet on the stirafoam. I have charge 4 and 8 280 batteries for 5 days. Cant get above 3.48. Using the same white charger you have. Asking for Aliexpress to take them back. It appears they want me to pay the shipping. Will know in a few days.
I received them from Hawthorne CA. They had to know these were not good batteries. Do you have any thoughts Thanks
I set the charge at 3.65 also moved up to 4.5. They just wont take the charge. I really feel ripped off by Aliexpress.
They charge very little at a time. I even tried just one battery. WTH
Cells are Lipeo4 280 and are Variacore
Tried to top balance in parallel
Replace the stock output cables on the Power supply. To much losses in thin cables and alligator clips. Use thicker cables and ring terminals and you will get much more amps to the batteries.
Интересно, почему нет бмс с отключением заряда на каждую ячейку персонально?
Те, где уже высокое напряжение от заряда отключить, а остальные продолжать заряжать.
На самом деле это не так. Заряд идет от основного отрицательного к основному положительному. Невозможно извлечь одну ячейку из батареи, чтобы другие могли продолжать заряжаться. BMS работает, отключая только минус, поэтому она может отключить только всю батарею.
Le mieux, c'est de faire un court-circuit avec une résistance de quelques milli-Ohm aux bornes de la cellule qui montre une tension trop élevée. Un BMS manuel ! 😉
280 amp hrs ,, 12v
How many solar watts to comfortably charge these lithiums .??
Well, four cells made into a 12v battery, at 280 ah, will produce about 3,584 watts hours for the whole batter. If we assume you get about 5 hours of sunlight a day (could be more, could be less), then roughly 715 watts of solar are needed to charge this pack in a day. A bigger array will charge it faster, and a smaller one slower.
👍👍👍
you said if there was a subject that we would like you to cover let you know. I would like to see a video on how you pick the right size BMS for your battery. I am building a 12v 560Ah battery with 8 x 280Ah cells and I can't find any video's on line that tells you which BMS to get.
Try Overkill Solar
Thank you for the suggestion! I've heard good things about overkill and I will be posting my own experience with Daly soon enough. There are MANY BMS options and the prices between them can vary immensely. The main factor is that you want to make sure the BMS is rated for 20% more amperage than you need. So if you want to draw up to 80 amps at a time, make sure to get a BMS that can handle at least 100 amps. Otherwise read reviews, and decide if you need things like bluetooth and low temperature protection (if they will be in an unconditioned room for instance).
@@Spridle60
And you can get those with a USB or Bluetooth dongle.
Then you can just check the app and see exactly what's going on with the battery cell by cell.
And it's easy to program the parameters.
Some of the bms's have a third lead on them that allows the battery be charged by solar panels or charger.
But will still have outgoing power disconnected until the voltage charg comes up high enough for the battery to re-engage output power from the BMS.
It can replace lead acid battery.
Number Check Please for Long Term Storage
at about 11:15 minutes in the video...
You said for long term storage to store them below 50% charge. Then you said that's between 3.275 and 3.3V or 20-40%. If my math is right that would be 67-70% of charge (if 0% is 2.5V and 100% in 3.65V). 20 to 40% charge would be 2.73-2.96V.
Also, cardboard between the cells? What about cardboard derivatives? Or paper? string or cellotape?
Thanks
The reason that is not correct is because the voltage curve is not a straight line, check out this link: diysolarforum.com/resources/general-lifepo4-lfp-voltage-to-soc-charts-tables-12-24-48v.109/
I think between the cells you want something that is insulating, but also is conducive to moving heat. Paper or cardboard will do a good job at insulating the cell from one another, but not at dissipating heat.
@@TheWilltoBuild Thanks for the link. From that table on the link 40-50% would be 3.250 to 3.363V. I realize voltage is a problematic way to measure capacity in the flat part of the curve. From that linked table 3.275 to 3.300 should be 60-70% charge. So which range is preferred for long term storage? And I know you don't charge these cells if temp is below freezing. But what about storing them? Is it OK if to leave a half charged LiFePo4 on a boat for outdoor winter storage where temps will routinely drop below freezing for extended periods but with no charging going on.
Thanks for the videos. Very helpful to see different presentations.
The bit about cardboard was a reference to this. 2 minutes well spent...
th-cam.com/video/3m5qxZm_JqM/w-d-xo.html
I am working on a setup for a boat using very rigorous maritime engineering standards so cardboard's out. No cardboard derivatives....
But seriously. I would choose something like electrically insulating fiberglass sheet between the cells. McMaster Carr sells it. My concern with these cells (I have 16 of them) is the delicate terminals. And I think the torque spec on the terminals may have to do with what is happening inside the cells where there is a plate attached to the base of the terminals that the actual prismatic cells attach to. Over-torquing the terminals may twist that plate and stress those connections. I am trying to find more on that.
Thanks
Lifepo4 prismatic cells must be compressed, EVE advocates compression, TopBand also advocates compression. Just also looked up Lishen LifePO4 request compression for any warranty.
Now for LifePO4 cells, I would Top Balance, this way the BMS doesn't work as hard, and also discharges equally. If not top balanced, They will not discharge equally.
Thanks but didn't we just hear all that from the video? I would have hoped you would have gave some tips on how much or how to compress...
@@JM-yx1lm each MGH has different ratings, just pull up their spec sheet and or contact which ever brand you have. There’s so many different mfg’s
I agree, definitely look at the spec sheet for details. I didn't want to get too into the compression discussion here, because there is a lot of debate on the topic, both in terms of how important it is and how to actually go about doing it yourself. I'll be covering that in the future after more research.
The compression thing surprises me. I would have thought to put some spacers in there to facilitate cooling. Perhaps someone makes something like cardboard, but in aluminum.
@@jimsteele9261 I like the thought of airflow/ cooling as well. Aluminum in between could go terribly wrong if the positive charged case wrapping ever developed a puncture or melted. So it would at the least be anodized to make it non-conductive. If someone mfg a corrugated aluminum sandwich maybe 1/4" thin that was anodized it would work brilliantly but suspect its cost would be very high as well.
Can we use it in inverter .
You can definitely use an inverter if everything is set up correctly.
You rammed the voltage message home!
It is probably the most important!
What is .2 c?
C is basically the capacity of the battery. So if the battery has 20 amp hour capacity, then .2C is 4 amps, and .5C is 10 amps.
I top balance, no sense bottom balancing them because the bms is going to top balance them anyway.
That is a good point, most BMS just burn off ah at the top.
I found that the BMS (Daly in my case) did not burn off near enough current to top balance cells. The safety would kick in to stop charging as soon as one battery (the weakest one tops out the quickest as it has the lowest capacity). I had to go back to a parallel string and charge at 3.64v (my safety choice) for maybe a day or two to finish top balancing them until the string took less than an amp (saturation). That made a huge difference in getting the cells at the same voltages (within .002v) I see why some setups use active cell balancers.
@@jamesbsa6450 Yes, always top balance before hooking up the bms. People that don't use a bms (very risky), will generally bottom balance, then keep the pack between 80% and 20% for safety.
@@SpeakerKevin in my case I didn't have a regulated 0-50v bench power supply to safely charge at 3.65v at the time I started my build, AND I wanted to (safely) use the 28v 13a battery charger I had at the time to accelerate the charging of my 8s 272AH Lishen set, so hooking up the BMS was a must, to protect the individual cells from over voltage. It got me most of the way there but had too much cell variance to get me within the range of my liking, so later bit the bullet and bought the Regulated PSU and dialed in 3.64 with the batteries rewired in parallel to top balance the safe and effective way without a cell balancer.
Sounds like an adoption agency for batteries, they have high expectations and get unhappy very easily.. great vid btw.
The connection should be series or parallel.
I was hanging out for comments about active balancers , but you left me high and dry 😕
I am going to try out my active balancer this week if I have time. Otherwise maybe later in August. I do want to talk about them more though.
20% charged = 3 v and 90% = 3.35 v ? Somebody has made tests to find these safe limits ?
There is a well established voltage curve for lifepo batteries. It is surprising how flat it is, but that is the truth.
I am not sure why you seem to think that repeating the information 2 or 3 times is necessary? Saying something once to an audience that is interested should be sufficient and would shorten your videos significantly. I find the repetition extremely annoying. Otherwise, the videos have good information.
I come from a background in education, and repetition is key for remembering.
Interesting tidbit about acquiring lithium for batteries. They "mine" it by extracting it from groundwater. They're pumping the water out onto flatlands in order for it to evaporate. Groundwater isn't being replaced as quickly as it's used. Especially since groundwater is the major source of water needed for crops etc.
I.e. People who think "electric" anything is better for the environment are basically WRONG.....
@IcanFartLOUD Well, you better not us a cell phone, computer, tablet, cordless tools, etc., or you will be supporting this terrible consequence to the environment. BTW, lithium is abundant in the earth's crust and you can extract it out of dirt.
Lithium is a medium to rare mineral , cobalt which is used in every luthium cell is a very rare and expensive mineral , lithium chemistry batteries are efficent but are not scalable long term , and most certainly are not enviromentally friendly , lithium chemistry batteries can store electrical energy more densely than any other chemistry for the fore-seeable future .. consumer demand for higher density and efficent electrical storage drove the development of the chemistry without regard to scaleability and damage to the enviroment , electric cars , transport , dont offer a better enviromental outcome than competing technologies no matter what the marketing says . Oh ps all lithium used by industry today is mined from groundwater , whilst lithium exists in dirt / earths crust its never been extracted outside of a laboritory in this medium and the resources reqiured to extract lithium in his way means it probably will never be.. beside the point cobalt is actually the mineral that makes lithium batteries unsustainable as a chemistry