How to Series Connect 12v LiFePO4 Batteries, and Top Balance
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- čas přidán 2. 06. 2024
- 12v Lithium batteries, (12.8v LiFePO4) are becoming very common building blocks for our solar off grid systems. It's even popular to series connect them into 24v, 36v, and 48v configurations. However, we still need to be cautious to treat these batteries well. I'll demonstrate how to top balance the lithium iron phosphate batteries for longer life and more capacity. This technique will help prevent nuisance tripping of a battery cutting out. I suggest performing this step when you first get your batteries, and then annually after that as a maintenance task.
In this video I not only show you how to top balance, but also why. I'll demonstrate what happens when you don't top balance. Then I'll demonstrate how much better your performance can be if you do.
Thanks for watching. If you would like to help support the channel please go here: / davidpoz
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Balancer for 12v batteries in series: lddy.no/tczy
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Finally! I've bought some new 12.8v LiFePO4 batteries, with internal BMS, wholesale from a company that went out of business and their literature says do not exceed four batteries in series or two in parallel. Now, I've bought six of them at once with the express purpose of connecting them in parallel to keep the voltage at 12 and crank up the kw hours. I was bummed until I realized that all the channels I watch have multiple, multiple batteries connected in all sorts of configurations. But this is the first set of "lawnmower battery" style of batteries I've seen anyone experiment with on camera. So thank you for easing my mind on these. I got an awesome deal. Best deal I could find anywhere for new, 12v LiFePO4 batteries. They're all brand new batteries, but still quite a bit of money for me to spend.
These pre-Mountain-Man era videos are still worth watching again.👍
Haha, thanks.
Great information and thanks. I replaced my 12v lead-acid UPS batteries with LifeP04 13 months ago without knowing any of these issues and got four hours plus of life for the Wi-Fi. Here in South Africa we're sometimes facing twice a day power cuts for two-and-a-half hours at a time, so it degrades lead-acid batteries very quickly. Yesterday my UPS refused to switch on. I think I now see the problem. I will try balancing the charge across the two LifeP04s, assuming one is not damaged, and give them a go again. In the meantime, I bought two new lead-acid batteries. They won't be wasted - I will soon need them for the garage and gate motors the way things are going....
BTW, thanks for responding to my last question. Appreciate you keeping up with the conversation!
Thanks David for sharing all these video, get the best out of 2021, cheers!
Excellent video Dave. It was interesting to see the capacity increase after balancing. Thanks!
You helped a lot. I have a 400 aH 12V system with four 100 aH batteries. I use all in parallel and was concerned about all four and "top balance" ... I have them in a fairly sealed wood box and it would/could be difficult to charge each battery individually. I hope to expand to 800 Ah total all at 12V .... I already had/have a Victron 12V multiplus 2 3000Va and the loads are low but when we have long cloudy days I want the capacity to use ... and only use the charge system of shore as little as possible. I mostly have been using only solar but seasons change. pat
David, thanks for all your help and innovation in 2020. Here's wishing you an even greater 2021!
Happy new year to you too.
Well done, per usual. Keep up the good work, David!
Thanks David, Excellent as always! Love your Channel, keep up the great work, it's very appreciated!
Thank you for making and sharing this video.
Happy New Year, hope you and family are healthy for 2021.
always good info. happy new year. keep the vids coming thank you.
Fantastic lesson. Thanks very much, Dave.
Very Well explained it was full of information I needed. Thanks David.
Great explanation. It makes a big difference especially with LiFePO4 of all chemistries!
Thanks for watching LithiumSolar.
Hi David thanks for all your instructive videos thanks to you I am starting a project to make a 10k inverter happy New years and take care from my cold city Montreal you're the best
What a great video. Very useful information. Thank you
Great vid David!
Thank you.have a great weekend
Happy New Year to you and your family
Very nicely explained!
my guy. good job in explaining this. thanks a lot.
Thanks brother. I am going to shar this with my friend. He is running 8 of them on his boat. God Bless.
Thanks for watching Bobby. Happy new year to you. I hope this video helps your friend out.
Happy New Year to you and yours David... Keep up the good work on your channel. Great info on LifePo4 Battery maintenance. BTW.. I like your Poz Cad drawings...
Thanks. Yeah, about the drawings... I'm not great with computers.
I've had good luck with the JK active balancer with a BMS at the whole battery level as well as with separate batteries put into series like this. I've made a harness for each battery system I've put together and eventually ended up buying an active balancer for each one. It especially works fast when under a slight charging or discharging.
There are some other balancers out there with good reviews too.
One of the most outstanding awesomeness videos of lithium batteries ever
Happy 2021!
Great video. Super explanation. I learned a lot. Thank you. I didn't know that charging the battery(ies) up to 100% was a bad idea.
Oh, I really love my dirty lead acid batteries. Great video, and happy new year.
Same here, I have 106.2kwh of them, they are simple and trouble free. Yes they weigh 8000lbs, but they are fine.
@@camarocraig7060
trouble free? who are you trying to kid?
This is a very clear and concise explanation. I’m building my first system right now, 48 V.
Thank you
Your welcome. Remember, the best thing is to buy a 48V battery from the start. This video is more for people with an existing 12V system, who want to re-configure their existing batteries to 48V. Since you are starting new, please consider buying 48V batteries. Here is are some affiliate links to consider:
48V waterproof battery (good for Vans, RVs.) On sale right now: signaturesolar.com/eg4-wp-lithium-battery-48v-100ah?ref=4_rHcgZ9x-TiF-
great stuff sir. happy new year, loyal subscriber
I have two 12v lifepo4 batteries and the supplier just says "do not connect in series" but they don't say _why_ but now I understand why. (and also, it seems that it's not that bad if you do, actually)
Really great video! I helps with yours grafics 👍👍
Thanks. I tried making those graphics on my computer, but I'm just not very good with it. So I drew them out.
I am from Iraq 🇮🇶 and I so love your channel. You do a great job 👏 in renewable energy.
Happy new year
Brilliant tutorial David. Many thanks from Australia! I have a pair of 12v LiFePo4 batteries I need to put in series, but have been told by the manufacturer that's a no-no. With the research I've done, and having watched this video, I'm pretty comfortable they'll be fine once they are properly top balanced. If not, it'll be a lesson learned! LOL
Hey Bruce,
Fellow Aussie here in the same situation, how did you'd go? did is it holding up? Just bought a pair of the same type also wanting to hook em up in series but just noticed the manufacturer warning against using em in series. Unsure what to do atm. 🤔. I thought they were a bargain when I saw em but now not so sure.
learned a lot, ty!
Thanku David ❤️
That's cool, you're showing people that they can make their own busbars!
This was extremely helpful and very well laid out and explained.
Just purchased 4x 12V 200Ah (200Ah bluetooth BMS) to be coupled in series-parallell to 24V.
Thanks a lot!
Your welcome. Best of luck on your build.
Another outstanding video.
And absolutely necessary for the DIY folks!
I have tried to explain this scenario to other people but they just tell me that if the batteries all have a BMS in them there is no problem hooking them up in series,
Your video just highlighted the problem.
The BMS protects the battery it is attached to, but in a series connection, you are only as good as the weakest battery,.
The 'best' solution for that problem would be if there were two more contacts on each battery,, (one for each cell), which would allow you to attach a 16S BMS EXTERNALLY,.... thus eliminating the need for frequent top balancing.
You might want to suggest that to any battery manufacturers you deal with.
The industry needs batteries with that capability, and it would only cost a few pennies more per battery, (and may allow the internal BMS could be eliminated).
One other possibility would be to use an external BMS that would externally balance the voltages across each 12 volt battery so you would have the internal BMS balancing the 4 internal cells in each battery, and the external BMS balancing the 4 batteries.....
Of course that would require someone to design a BMS for 4 (or more) series BATTERIES instead of 4 individual cells...
Happy new year 2021 and make more videos👍....
Freakin awesome content mate 🤠👍
Wow you are becoming an actor over intro haha^^ good shout out ~~!!
Helpful idea again~~
Kilovault actually recommends charging each battery individually to 14.1 volts before putting them to use.
Very good idea for this balance. It really help battery get long cycle life. It is same technology why we need balance cells before assemble battery pack. But normally BMS will have balance function, but this solution do not have the balance function, so as time went by, the unbalance things still will happerened. That is why lithium battery is not good for in series, only if with a master BMS. And one more things is that: do not series your lithium battery as you want, because most 12V BMS electronic chips can not handle that high voltage, means if high voltage, the BMS chips will broken. If you assemble a 48V pack, those chips should working with more than 100V Chips, and for sure the cycle life is not as good as the single pack.
How would the 12v battery's internal bms know / suffer if it's part of a 48v battery?
David (and family) happy New Year and hopefully many videos like this
I don't know if you are clairvoyant but this is precisely the problem I was dealing with right now. I have 10 batteries 12V200A for a 24V solar panel system. Now I know why I can't get the capabilities of this set. It does take a lot of work to disconnect and balance them but do it and then load between min and max.
Thanks.
I glad to help you solve the problem. With 200ah packs you might want a larger charger, otherwise it will take awhile.
Thank you!
Thank You ,new to this ,so very happy to learn ,now if I can just remember .LOL
You need to check with particular 12v LFP batteries that they are series stackable to number you intend. Many, typically low cost, 12v LiFePO4 batteries BMS's are only made with 20v or 25v breakdown MOSFET's so may avalanch if BMS switch opens when run at 48v stack. Higher breakdown voltage MOSFET's cost more for same current ratings.
How exactly does this play out? I'm using 4x12v in series, each of which say not to go higher than 24v, and they still work fine. I'm not saying you're wrong, I just don't understand the risk.
@@jimmybrad156 Nothing will happen unless one of the BMSs decides to disconnect. Then (as per your other question) it'll suddenly know how many batteries are in series with it,. Have they been fine over the three intervening years?
thank you for battery video
Your welcome. Thanks for watching.
Great content and sound advice man, keep it coming. But if that's all those batteries are putting out, they're better off being scrapped.
You could also capacity test each cell individually.
For people confused, When stringing in series, if your charger only monitors the overall voltage. You have to get a multimeter out and double check the voltage of each pack. If one pack is constantly being pushed to a much higher voltage than the rest it will degrade and get worse. To counter this you have to reduce you charger cut off points. It will reduce day to day capacity but will dramatically increase the number of cycles which is more valuable return on your investment
Yes, I was recently in communication with a Chinese company that uses CATL cells in their products. The advice was to keep the pack between 20-80% but if you want maximum cycles then 50-80% with a >6000 cycle life is what they claim. Obviously the latter would involve buying a larger battery than you might otherwise need... perhaps a marketing ploy? I guess we will find out who was right in 20 years but my guess for best practice is to keep the pack out of the steep part of the charge/ discharge curve and let an active balancer keep the cells within a certain limit of each other.
What was the voltage output of the charger that was used to charge all four in parallel? A voltage output of 12V won't charge 12v lithium batteries, I believe it would have to output somewhere around 14.8v if I'm not mistaken.
Excellent.
Top balancing of any Lithium batteries seems to increase their output. I'm working with some 4V rated packs and if charged as 5 7S they only will output about 14 Amps out of the 22 they should. But charge them as 7 5P cells with the units sharing connections, they charge higher and output 20 Amps before the BMSs shut them down. I currently have one pack for testing that all were in parallel charged and they went to 4.3 Volts each without the BMSs shutting down with all being charged at a total of 2 Amps. No swelling of the packs either. The units are going to be used for destructive testing to see how high the charge Voltage can be on the 28 Volt pack before something gives. Each of the 7 cells will have its own meter. If they withstand 36 Volts across all 7 (5.14 each ) then a test also will be done to see what the most WH is on discharge. I also have a single cell for testing without a BMS and one of the twins that I will see just how high the input Voltage can be before something gives. All of them will be over water so if they catch fire, they will drop into the water.
It would be far more ideal if all of these consumer LiFePO4 batteries included an externally accessible balance port like some of the early units have. Then you could easily set up whole pack balancing and monitoring rather than them being a black box. But I guess that is why the individual cells and programable BMS solutions are the norm in the DIY community.
there are 12v balancers on the market if you are concerned about it
Hello
I have 4 nos 12 vbattery it have individual bms can i connect in series
@@afgamer322 The video is showing four LiFePO4 batteries with individual BMS built in. So what he is doing is what you should do as well.
I think that I understand what you are saying. Even though each ready-made battery has a dedicated BMS that monitors the overall health of the battery pack in each ready-made battery, there is no real way of telling what the health of each cell is that makes up that battery pack. Essentially, the only way of telling what the health of each cell is in the pack is to hope that the battery BMS has the capability to tell you the health of each cell. Otherwise, the only other way is to tear the battery apart and test each individual cell in the pack.
Honestly, I don't ever recall any of the channels or books that I have read say that there are ready-made batteries that can tell what the health of each individual cell is that makes up the battery pack in a ready-made battery. On the other hand, all ready-made battery packs in ready-made batteries that I have seen and/or read about do have BMS protection. I would bet that manufacturers don't want ordinary battery owners to have the ability to diagnose and replace battery cells in a battery pack. Will Prouse does indicate that this is OK and has done so himself, but I bet that a person takes on a certain amount of liability by replacing individual cells.
Personally, I see not being able to monitor the cells in a ready-made battery as a problem, so I have decided to use individual 32650 cells to build battery packs and then monitor the health of each individual parallel group in those packs with a BMS that is able to do so. In my mind, if I can see that a group is underperforming and is readily accessible, then I can quickly do a visual inspection and/or test each cell in the group and isolate any problem cells. The only part that truly concerns me is the thousands of welds that I have to make to construct a pack of any size. I still get the "willys" just thinking about welding on a lithium cell.
@@westking7746 good job explaining your point
so we need a few relais to change the configuration from serie to parralel depending on charge or discharge state
I was hoping you'd do this video! Thumbs up and subscribed! I appreciate your detailed explanation!
Thanks for this. Do you think batteries in series need to be put in parallel every now and then, to balance them out, or is this just a one time thing?
I think once a year is good practice.
Thanks
I have just found that it is possible to get a balancer that works on 12 volt batteries. I got a PowMr HA02 balancer that works on banks up to 48 volt. I have installed it on my 48 volt bank of cheap LIFEPO4 batteries and it has given the bank much bigger capacity.
It would be better if you could get to the series connections as well as the outer posts. Nice video
Rather than reconfiguring the batteries in parallel, can you boost charge the low batteries individually within the 48V circuit?
I didn't seem to find it in the videos or the comment. When you have a 48V set up, what BMS are you using? Are you using the same bms when you do a parallel connection for the 12V?
If these were individual LiFePo4 cells, that would be a 16s bms for a 48V, we would need a different one for the 4s configuration at 12V one? Or is yours the one that has 4s~20S range?
HNY David. So you found one battery at 3:00 that hit its top charge value and BMS switched off charging. You then dumb charged all batteries at 12v (to 14v+) and reconnected them and ran another 48v capacity test giving you 6% gain (but of course because you dumb charged them all to 14v+. What was the result of the next charge at 48v after this balancing with BMS? I'm curious to see if the balancing dumb charge actually made a difference. Thanks for your efforts, you're the best!
I came across this video while looking for how to balance brand new batteries prior to putting them in the search. I knew it was a good idea, I just didn’t know how to do it. This video was extremely informative and well presented. However, I still don’t know the nitty-gritty simple steps I should take to balance my batteries. Well that’s not entirely true. How do you spell come together in parallel and let them sit. Which I actually think I have time to do. As it is now, I’m going to have to find out details as to what type of 12 V charger I need to use speed that process up.
Great explanation video. I would also mention for new users to not just parallel random voltage batteries with thin wire as the current transfer to the lowest may be great and melt the wire or minimum heat up the wire. I would charge each battery up first, then parallel to balance (Maybe you did and I missed it😉)
You are right, and it's a good point. Maybe I edited out that clip, It took me 3 days to edit this video and some stuff gets cut for time. I could parallel mine because they were 0.02v delta. When people ask me about paralleling I tell them to be within 0.10 volt delta to keep the amps low.
@DavidPoz I completely understand during edit LOL. I have heard you say that in other videos!
As I red in VictronEnergy The Wiring Unlimited Book those big amount of parallel battery stack pieces recommends connect to charger/load diagonally, because different batteries and wiring resistance cause a different power drops and amount of current consumption.
But anyway, it's so very good and useful video, especially right now here in Ukraine.
Thanks/Дякую.
Hello and thank you,! There are a few different ways to connect in parallel, which is most favorable for batteries? (lifepo4) like you connect or connect everyone to the same busbar with equally long cables?
The short answer is yes, Bus bars with equal length cables are the way to go. However, we could do a little math and get into that in more details. There are a few different configurations that can work if you are trying to tidy up all the long cables, or something.
Looking to replace my dad's mobility scooter batteries. He has 5 12v 20ah batteries in series. You think this setup will work with in his scooter? Love your videos. Happy New Year !!!
Lithium iron phosphate would work well though you might need another charger and BMS but they would likely take up too much room as 12v batteries. You could get individual cells but remember in the lead acid you only discharge about 50% of their power and these can provide at least 80% of their power. They also weigh about half as much. It might be difficult to find 20ah or less cells to make a pack for that scooter that would fit in it and larger cells would also be pretty expensive. Are u SURE the cells are in series and not parallel? Check ali express for cells and make sure and note their size and whether or not they come with busbars and terminal screws .You would need 20 individual cells in series and a BMS and a comparable charger though the one currently used might work as long as you use a BMS.
Isn't this the same situation as when combining the cells internally? And isn't a BMS necessary to make that work long-term? Not sure, maybe you could go another round?
Great content! What is best practice when building a larger 48v system using the eve 3.2v 280 ah batteries. Top balance and put in 16S or 4S 4P or 8s 2P? Thanks again, enjoy watching your content!
The first one. Top balance the cells. Then arrange them into 1p16s using one BMS rated for 16s. It's always best to build a battery to the voltage you want.
@@DavidPozEnergy Thank you!
@@DavidPozEnergy What would you recommend for a good BMS! I was looking at getting an Overkill.
I've never used Overkill brand, but they seem good. I have no reason to think it wouldn't work well.
I have used the BMS's from Battery Hookup and they work well. My discount code with Battery Hookup is "DAVIDPOZ" which helps the channel through the affiliate program.
Great video once more TY for dropping all this wisdom on a up and coming noob :) ! I just bought a 3 pack of these Power Queens on sale for $750, can I use just the three in series for the 36-watt system? I want to power my Pecron E 2000 at night or on cloudy days or do you recommend the 4th so I can run a 24 volt parallel, 2nd question for my output from the batteries (8AWG) can I just run them into an MC4 to hook into my aviation plug? Thanks in advance and also for inspiring me to get partially off-grid :)
I've never tested a Pecron E2000, so I just looked up the specs on it. Looks like you can add an expansion battery (EB3000). I assume you are trying to make your own expansion battery? If that's the case, then try to match the specs of the expansion battery. It is a 25.6V battery (usually called 24V, but in LiFePO4). Sorry I can't be more help, but I haven't tried making an expansion battery for a pre-built portable power station.
David I always enjoy your videos. Why isn't there a 48 Volt BMS using 4 12 Volt batteries in series? I have 4 100 AH AGM strings in parallel in my 48 Volt system. It seems to me there would be a large demand for a BMS for this configuration. All I have found is a Victron product, but you need more than one for each string. Any ideas? Thanks
This one: lddy.no/tczy
@@DavidPozEnergy I love alt e utube videos. This looks like what I need. Many thanks.
Thanx David! Good Video, easy understandable. Absolutely does makes sence.
How about using a 4s ballancer for your string of packs? 12V something....?
Sure. Alt-E sells one made for this purpose. I linked to it in the description.
@@DavidPozEnergy sorry, must have missed it.
Keep up the good work!
Hi David please connect the in series to an inverter and do a capacity test
Beautiful & Very informative Information. Thank You so much. Could a person charge each individual 12 volt battery 🔋 to do the Top Balancing & achieve the same results? Thank You again
Yes, you can do that too.
@@DavidPozEnergy Thank you so much for replying. I’m new to the Solar world 🌎. I just bought 16 100 amp hour Battle Born Batteries 🔋 with the Victron inverter that battle born recommended for my 48 volt set up. I also bought 8 Solaria 400 watt solar panels. I’m excited to learn. I’m learning from you & Will Prowse of DIY Solar. You two are the best teachers in my humble opinion. I’m putting my system inside of an all aluminum cargo trailer so I can have portable power & an option of a toy hauler too. Thank You again. I’m a brand new Subscriber to your channel too. Please stay Safe & Stay Free 🍻 🇺🇸
Thanks for the video. Question, when using series configurations, such as a 24vdc xxxah with a bluetooth module, how do you use the bluetooth dongle in each battery to monitor the individual pack? Two batteries, two bluetooth dongles how to monitor? Thanks is advance
Each BMS needs it's own Bluetooth dongle. Then inside the App you will see the different serial numbers and you select which one to open. I have about 8 batteries in my garage now all with bluetooth.
@@DavidPozEnergy Thanks for the info...regards keep up the good video's
Great video David. What charger do you recommend that can be programmed to cut off at 56V? I'm also planning on setting up my Renogy 500A Battery Monitor on my dash to be at zero percent charge when the voltage hits 49V to ensure I'm not dipping into the bottom 10%.
I use solar MPPT charge controllers. Currently I'm using a Victron one, but most MPPT controllers can be programmed. However, if you are asking about a wall charger, then I use this one: signaturesolar.com/eg4-chargeverter-battery-charger-48v-100a-5120w-output-240/120v-input?ref=4_rHcgZ9x-TiF-
You can leave them all in series and use a 4 bank charger. Boaters used these all the time. They will charge the batteries independently from one another when in series configuration.
Thanks for sharing a tip from the marine world
I think that would actually be a more ideal solution. Unfortunately I haven't seen solar chargers with that configuration. Perhaps some sort of external balancer could be used instead to achieve a similar effect.
Do you have to discharge them before hooking them up in parallel and charging them?
What about balancing the four 3.2V cells inside each of the four 12.8 batteries?
There’s no external balancer that can do this, or would you have to break them apart and go with a 16s bms?
Hey there it is, maybe you could do a vid on one
www.altestore.com/store/meters-communications-site-analysis/meters-battery-monitors/ammeters-voltmeters-battery-monitors/kilovault-battery-balancer-p41485/?gclid=CjwKCAiArbv_BRA8EiwAYGs23I4CbWqvtXdmBGIHHWZvyfHWYPW5L47pUnkT3NGm2nWwFkS0A-XabRoCWbwQAvD_BwE#KLVBATTBAL48V
Is the balancer in your link the same one in the video? The balancer in the video looks like 4 individual balancers. Thank you
for 10 batts hooked in parallel 12v 70 amp each would a 80a circuit breaker installed between the batts and the charge controller be ok or is has to be greater amp breaker?
Hey David... I've been watch your channel for a while, I was wondering if you do any consulting or custom battery builds? I'm looking for someone who can build a specific battery setup for me.
Sorry, I don't sell batteries. If you want to discuss build ideas, then I suggest Facebook group "DIY Powerwalls".
Thank you for the video! Does it make sense to use the 4s 12V equalizer? There are options on Amazon and Ali for about $50.
I once tested some active balancers (for single cells) and found it made my pack worse. Since then, I've steered away from them. That being said, I've never tested the 12V balancers made for 4x 12V batteries in series. They might work well, but I don't think they are necessary. If all 4 of your batteries in series are the same type, same age, then they should stay balanced well over time assuming you top balance them together.
Just ran across your channel. VERY good information! I am looking to build a bank of 4 x 16 3.2 cell 280Ah batteries. How would you address the top balancing with individual 3.2V cells? Would the BMS be across the entire 16 cells in each grouping? (I think so) What about active balancing while in service? I am very new to this as we are putting up a 2 phase array to defer some home electricity and also supply power to a new EV called Rivian! 65KW capacity. Any suggestions would be appreciated! Thanks
Hi Jim, Thanks for checking out my channel. When you say 4x16 cells, sounds like you have a total of 64 cells. I'd wire all 64 positives together, and all 64 negatives together and top balance (charge to 3.65v) This may take a couple weeks depending on your charger. I've actually done this with some EV cells: czcams.com/video/lAqUfC-zR4M/video.html
As for the active balancer. I own an active balancer and use it a lot when I'm refurbishing battery packs. However, I don't recommend leaving an active balancer attached while the battery is in service. I have found the active balancer throws off the readings on my BMS, causing my BMS to shut down. Instead do a real good top balance, don't rush it, and then allow the BMS to just maintain balance over time.
@@DavidPozEnergy 4x16 - 4 banks of 16 3.2V cells (51.2V) each 3.2 cell having 280ah.
@@DavidPozEnergy second item if you could. have you done any posts regarding using portable power packs that in my case have lost the ability to charge due to the mini USB charge port is loose and will not make constant contact. would like to continue to use the batteries (Gorilla Gadget 20000mah) to charge my portable devices, Thoughts please!
I use a 48v battery balancer, it hooks up similar to a bms except it has a +/- for each 12v battery and keeps each battery at the same voltage
I was wondering if there was such a device. Do you have a link to the product?
@@judo-rob5197
www.ebay.com/itm/333113199150
www.amazon.com/KRXNY-Battery-Equalizer-Batteries-Balancer/dp/B07FD1R6Q1
It’s always best to use/build a 24, 36 or 48volt battery to get those voltages instead of 2, 3 or 4 12volt batteries in series. When charging in series even the best batteries like Battle Born will eventually go out of balance it you don’t take some extra steps. Top balancing the group will work for a while but you will need to reassemble it in parallel periodically which is a hassle. There are only two other ways. One way is to have each battery have it own independent charging like using the Ionic bass boat charger. The other way is a PowMr battery equalizer 4x12V on Amazon. This is not to be confused with a BMS but it’s kinda does the same thing with batteries but not cells, however no protection features.
So this pow Mr when put on 4 12v lifepo4 will balance the batteries and that all you have to do?
I guess in a single 48v the bms will take care of the balancing?
But wouldn't that be of a reduced capacity as compared to bigger batteries in series?
Also why not use a bms for the series connected batteries?
Total noob here 😀
I need to replace lead acid batteries 12x8
Have a 96v inverter
DAVID HAPPY NEW YEAR IN 2021 ..... WE CAN CONNECT THIS IN SERIES AT 24 VOLTS
CHEAP Miady 6Ah LiFePO4 Battery 12.8 VOLT?
I just watched a video of the Volkswagen battery install...where is the video of it driving?
Turned out there is more wrong to the VW than initially expected. It won't be going on the road.
One important note. This is only really true with batteries of similar capacities and internal resistance. With dissimilar batteries they will quickly go out of balance again. OK - they’re top balanced and theoretically each battery will discharge the same amount of energy in series - but in practice a weaker cell may have far higher internal resistance and be harder to recharge forcing the pack out of balance again. Series connecting 12V LiFe batteries is a gamble although up to 48V is supported by some high end manufacturers. Check with the manufacturer.
Higher internal resistance does NOT matter. Battery cell wih higher internal resistance will still recieve the same amount of electricity (Amp*hours) except at slightly different voltage. The real problem is uneven colombus efficiency or self-discharge. Lithium batteries are also very special in a following way: cells with poor colombus efiiciency (
David, can a 60 amp 16s lithium charger charge a 48volt 4s lithium 20 Ah battery both have a management system
Hi David. Great video. I picked up 5 Renogy 12 volt 50 ah batteries with the intention of connecting them in series, about 70 volts when fully charged.
This was to power a covered mobility scooter running a 60 volt 1200 watt brushless motor.
I read some comments saying 4 batteries is okay in series, but maybe not 5.
I'm wondering whether to go ahead with a test.
Looking forward to your other videos.
One of my next projects is to put a 175 watt solar panel canopy on a 60 volt mobility scooter using a boost voltage converter.
Baby steps.
Thanks for your videos.
Careful, Renogy specifically says not to connect their batteries in series, only parallel. Not sure why he missed that
Hey David. Thank you for this. I am a snowbird spending winters in AZ. I switched to 3-12v lithiums for my 36v cart. I top balanced them new as you showed but I heard that one should balance them annually and you said that you will top balance if connected in parallel and left for a month or so. Can I just fully charge my 36v system when I’m ready to head back north, and then re-wire the batteries in parallel for the summer. Presumably they will balance while I’m away and then give them a full charge in the fall. Make sense or not?
Re-balancing them once a year is good practice. Also, Lithium batteries don't like to be stored at 100% SOC (state of charge). Ideally, store them around 50-60%SOC for the off season. I'd store them disconnected from everything and each other. When you come back to the golf cart, I'd re-top balance them.
If you leave them in the golf-cart while you are away, then make sure you have a main-disconnect turned off so that the 12V power supply, or speed controller, doesn't drain them while you are away.
When you come back to the golf cart, a way to speed up the process is to charge each battery to 14.6V with a lithium 12V charger. That will save you the hassle of removing them from the cart and re-wiring them to parallel.
Thanks again for the reply. Just to be clear. I’ll disconnect them from each other and the cart before I leave. When I’m back I charge the individual batteries first with a 12v charger. Then I wire them in parallel and balance them with a small charge. Then rewire in series and “Bob’s your uncle”?
Would you do a research and then a video about the energy pack in a laptop and periodical maintenance procedures in order to keep the battery as healthy as possible?
Thanks for the video suggestion. Are you talking about cracking open a laptop battery case and pulling out the 18650s? If this is some kind of computer program to run, then I'm not a computer engineer.
@@DavidPozEnergy - hey there, Happy New Year, physics is not about computer programs, a battery is a battery even though is an energy provider for a watch, a phone, laptop, car or a house, I think that your knowledge can be applied anywhere we "feel smell of lithium"
If you charge all four 12v batteries (in paraellel) to full using your 12v charger. Then you rearrange them into series...won't you have 48v full batteries? I found it curious that you swapped to the 48v charger (which is more expensive). Unless this is just a time saver or something?
Keep up the good work, David.
Here's a challenge. I am connecting a 15ah 4s LiFePO4 pack in series to a 15ah 16s LiFePO4 pack and charging it with a 60v charger. How do I wire it up?
Ideally you would find a 20s LiFePO4 BMS so that the whole thing becomes a 60V battery pack.
@@DavidPozEnergy Wow. Thanks so much, David, for the prompt reply
Yes. I see now that a BMS is the way to go. I have an active cell balancer on each pack. But it might be difficult to keep the two packs balanced between each other.