Compressing swollen Grade B LiFePo4 prismatic cells. Let's experiment. Don't try it at home.

[@rOSScOGITANS]

not all can understand how much work, time and passion for to do these tests, thank you very much!

[@SolarEngineering]

thanks!

[@pavelsedov9982]

Да , но английский с русским акцентом ужасен!!😢😢

[@reeread]

Thanks so much for the video. Sorry You had the problem with the seller and Alli express. I have been through so many disputes with Ally express sellers but I’ve just learned it’s not worth doing business.

[@SolarEngineering]

Yeah, unfortunately. You are welcome, hope this video will warn people.

[@amanofmanyparts9120]

Yup. been there, still waiting for the T-shirt to arrive!

[@realvanman1]

One important point is that, in your first test, the output cables were properly connected to the battery such that all cells will share current equally. In the second test, after the compression and the new bus bars, the output cables were not connected for equal sharing of current between all cells. Connecting them as in the first test would have improved the result of the second test to some degree.

[@rickard1802]

I love the perfectly alligned holes on the new busbars 👍👍👍

[@SolarEngineering]

it was huge luck

[@gregguithues855]

I just ordered some similar to these... Sold as grade A 320 AH. 16 cells delivered for about 500 USD. Shipping should cost most of that. I don't need full capacity but the price was so good to pass up. Excellent video. Thanks for the data. Greg in Hawaii.

[@Loolanga]

Hell could you chuck us a link to 16 cells for $500? Even if they're grade b garbage that's an insanely good price.

[@YelloJello]

I just received my 105 aH Littokala from AliExpress. 2 x 16 packs. Almost all had slight bulging except 4.

[@ForbiddTV]

Hey Greg, any update? Since you seem to have disappeared we aren't quite believing the deal you claim to have gotten.

[@gregguithues855]

@@ForbiddTV well thanks for the reminder. No delivery, lying seller, Aliexpress refunded with no fuss.

[@gregguithues855]

Btw I bought five sets total 20 batteries. Nicely balanced 3.293 and 3.294 voltages.

[@asdfdfggfd]

I think we are just going to have to accept that the chinese vendors of prismatic cells are going to over state the capability of their cells. This has been going on for two plus years and virtually all the vendors do it.

[@SolarEngineering]

I think the bigger problem is used cells. I'm "ok" with under-capacity new cells. But I guess these cells were used previously. But unfortunately, it's just a guess.

[@ursodermatt8809]

@@SolarEngineering my experience, the seller called himself "honourable" and then sent "A grade brandnew" cells that were second hand.

[@peterlindstrom8865]

Just like used car sellers!

Some cells were stored for long periods and not maintained. They can swell even in storage and they degrade faster if outside the storage voltage and temperature. And the Chinese overstate products performances since the 90s. There are plenty 900000000mAh 18650, sand filled cells on ali/bang/dx/etc

[@ursodermatt8809]

@ i doubt very much they keep cells for long periods in storage. they want to sell them as quickly as possible.

[@asArsenic]

I'm so glad that over here in europe a seller has to cover the cost of return shipping.

[@Frolleglse]

Are you sure? Is that something new? I had some issues where i also ended up as the looser due to high return shipping cost.

[@asArsenic]

@@Frolleglse No, this isn't new. You may be in the position to demand that you be reimbursed for your shipping costs. You shouldn't have had to pay them in the first place.

[@asArsenic]

@@Frolleglse Within 2 years the sellar has to repair, replace or refund a defective product at no additional cost to the customer. Prior to six months any defect is assumed to have been present at purchase, afterwards the seller may demand evidence that the product was defective at the time of sale.

[@Frolleglse]

@@asArsenic ok. Thanks for the input. I will refer to "EU directives" next time i end up in a bad position.. If a success I guess it will be the first time something good comes out of this EU crap..

[@asArsenic]

@@Frolleglse There are a remarkably large number of good things that come from the EU.

[@lukefarmer5391]

Great job! I believe compression keeps the electrolyte within contact of the most of the internal media. If a battery bloats the electrolyte is no longer in contact with 100% of the media. With out the media in full contact with the electrolyte I would imagine you would not get full capacity. In addition I have seen batteries that have failed and it appears that it was from media drying and separating. Cycling without compression will do both of these things. Therefore in my opinion compression is safer and adds life to the battery. I really do not believe the manufacturers of these batteries really care and say it is not necessary because they really have not done their own testing and are going off info from initial manufacturers knowledge from years ago.

[@mickwolf1077]

Something would have changed in the cell for it to bloat, likes produce gas maybe? Compression after bloating will increase pressure but still increase electrolyte contact.

[@marktheunitedstatescitezen185]

Great job with the video compressing your batteries I’ve seen many not as smooth as the way you’ve done it !

[@djluck95]

@SolarEngineering Nice video and I applaud you for testing this. Yes, it is not the most wise thing to do with bulged cells, but it is not that catastrophic. Even if you had used springs there would be some "expert" to find something to tell you it is not good enough. About the refund, there is a trend that only Amazon buys or big youtubers get a refund when they "discover" such cells. I wish you good luck with your cells and refund and hope to see an update video about your situation.

[@SolarEngineering]

definitely will post an update if any progress about return/refund.

[@CL-yp1bs]

@@SolarEngineering You can get refund if you make dispute with aliexpress... it will take a couple of months.. liiokala and varicore are known scammers.. still selling used b stock cells

[@SolarEngineering]

@@CL-yp1bs I did open claim, but Aliexpress declined refund.

[@peterlindstrom8865]

Regarding swelling and bus bars.. Why not use "soft" bars bended in an upward arc that will flex? Or just short thick cables in arc with a lug at the ends. I remember that cars used to have a flat braided connection on the minus pole down to the chassis that will easily flex.

[@gelisob]

would recommend that too, in case of decompression or expansion - you dont want to rip off terminals.

[@Sanwizard1]

Nice job. Looks tight. That being said, i just let my cells bloat as they want.

[@ericseidel4940]

Be careful, cells increase their volume during charging, so you can't do it like that. 1Kg per Ah is a good value so this pack need 300Kg so 75 Kg per screw. You need some springs to compensate for volume increase during charging. Compression should be done from the begining off cell life to avoid dentritic building between electrods and then wollen cells. These cells are already used.

[@HimmelbergerBus]

Maybe I’m late to the party, but was a proper too balance performed? Edit: looks like yes. To rule out improvements from cycling alone, why not perform the test a few more times? I’ve heard these can be “woken up”. What was the deviation at cut off? Also, I’ve been weary to cut the threaded rods that close. Not sure I can recompress if I needed to disassemble. Another pro tip, you can cut soft metals like aluminum and copper with a normal saw. Works great.

[@SolarEngineering]

>>Maybe I’m late to the party, but was a proper too balance performed? Edit: looks like yes. yes, top balanced all cells till 3.65V To rule out improvements from cycling alone, why not perform the test a few more times? I’ve heard these can be “woken up”. >> usually cells perform little bit overcapacity while new. What was the deviation at cut off? >> Since discharge rate was very low, all cells were about +-50mV Also, I’ve been weary to cut the threaded rods that close. Not sure I can recompress if I needed to disassemble. >> good point, I have some extra length on other side Another pro tip, you can cut soft metals like aluminum and copper with a normal saw. Works great. >> need to try it, thanks. Also I tried to search how to cut oval whole for studs to allow some play. Do you have any suggestions?

[@antonkireev4098]

@@SolarEngineering Я использую несколько надфилей разных размеров для получения необходимого профиля и размера. Медь мягкий металл и легко обрабатывается. Удачи.

[@josepeixoto3384]

I was scammed by Aliexpress also; 300 Ah only have 110 Ah; brand new,big,but only 110Ah and one cell even less; a dispute is going on, and thanks to your video,i refused a return and refund,i want a partial refund; i spent countless hours making videos and photos,all kinds of tests they asked for; the dispute is going on for 2 weeks now, what a effing nightmare; it won't be long now but i have a bad feeling about it; again,thanks for your video; you still lucked out, they have decent Ahs.

[@estartermanual]

I received 20-30% capacity scrap batteries, the same as your nightmare, 50h spent to only 40% refund

[@josepeixoto3384]

@@estartermanual Not too bad after all? º.º my UPDATE: after a 2 week battle, i received 187 euros refund, and that had been my sugestion to Aliexpress to end the dispute it is actually easy,time consuming but easy: FIRST thing is to prove with pics and videos that the product is NOT as sdvertised; SECOND thing is to say that (according to Aliexpress policy,READ IT!!) the Seller pays for the shipping to return the items,since he is at fault,not you THIRD, you WARN the seller that the cells and buss bars are now USED, they now bear the marks of the heavy tests he demanded during the dispute,and that you will NOT accept any excuses when he receives the items... º.º you then suggest a reasonable,for both, amount to be refunded if the seller does not pick the Cells up; he won't and you will be refunded.

[@firstbigbarney]

This is exactly the same problem auto mfgr are going to have with pouch cells,there is not enough compressive strenght in the housing to keep the plates properly aligned . The cylindrical cells have great strenght to be able to resist the outward pressure, the inner separators provide the containment needed for the vertical expansion. This is like a jelly sandwich when you squeeze the jelly comes out the sides.

[@tacticallithium7831]

There are no plates in prismatic or pouch cells.

[@firstbigbarney]

@@tacticallithium7831 It may be a foil but it is still a plate. They may be rolled or folded in the case.See kzbin.info/www/bejne/j6Okapp6eaeUocU

[@raphofthehills4405]

That's why in the Nissan's Leaf battery pack all the cell stacks are sandwiched between metal plates.

[@richardnanis]

Compression does not change the capacity - why should it? Its not working like a capacitor where the distance of electrodes playes a role :-)

[@basspig]

My concern about compressing cells is that it might cause an internal short between the layers of dielectric material inside the cells. They need to be able to expand naturally so that the pressure doesn't turn inward on the insulation layers.

[@dacreation369]

Do LiFePO4 batteries need a BMS?

[@SolarEngineering]

yes, overcharge/discharge could reduce cell life significantly.

[@otukucocker365]

You should do the compressed one first? the first one swol the cells and ruinds them?

[@kstaxman2]

Ordering direct from China is just a way of gambling. It's not if you will lose, its do you have any chance of winning? They hold the buyer hostage with the high shipping costs. Especially when even if you send it back they could still not pay you and then you would really lose.

[@Ihor_Semenov]

Спасибо за видео. Подскажите какой материал Вы используете для дополнительной изоляции между ячейками? Как он показал себя за два года эксплуатации?

[@SolarEngineering]

это была плотная бумага, батареи так и не использовал в итоге

[@farmerfb]

I did order a set of four 280 Ah batteries from this same company ( same ali store) earlier this year and they tested out at 283+ . It makes me wonder if they just fill in orders with pure crap if they don't have good stock.

[@SolarEngineering]

I think they build reputation and now is a time to cash-out.

[@5nowChain5]

they have mixed cells in stock, its random what you get. looks like he would up with 240Ah on average. if tested individually there might be higher or lower Ah cell in the group

[@tomstdenis]

It sounds silly but I always had a hard time pinpointing drill points on a bus bar ... I have no idea why I never thought to do it your way. Duh. hehehehe. Thanks!

[@SolarEngineering]

we are all learning

[@andreypolyakov9410]

any broblems with copper bars and aluminium contacts?

[@pierreqiu8147]

Will the battery explode when you compress it?, maybe now but maybe month to come. I got some grade B cell too but I use flexible buss bar.

[@kimmer6]

No, they won't explode. When they are overcharged, they create a gas and that causes the swelling. The blue plastic oval on top of the cell protects a scored aluminum burst disc which is set to relieve the gas pressure. The cells can swell about 3/4 to an inch in width before the little burst disc operates. Ask me how I know.......

[@w3bb0y]

What flexible bus bars are you using?

[@pierreqiu8147]

@@kimmer6 ok thank you, then should I leave the battery uncompressed or compress

[@kimmer6]

@@pierreqiu8147 I assembled mine in 2 packs of 4 cells, 8 long, 4S 12.8 volts. They fit tightly inside a wooden box. While I was testing them, I wrapped each pack of 4 cells in 2 layers of Fiberfix 10X tape. That is an incredibly strong tape with glass fibers embedded within. Then both sets of 4 cells went into a wooden box that I made and the free space on one end was shimmed tightly with a 1mm thick Bakelite plate the size of the battery side. The battery has been successfully operating since May 2021 and discharges to about 80% capacity by nightfall and recharges at about 26 amps when the sun hits the panels. The bus bars are the solid ones that came with the cells. There are times when I discharge the cells at 160 amps and recharge them from a generator at 75 amps. I have seen no problems with the cells in several months. I believe the excess gas that causes cell swelling happens only at charging at more than 3.65 volts. I do not think there is much gas production at all with normal operating voltages. If I make another battery, I will use the 10X tape to bind them together. They were designed to be compressed inside electric vehicle battery cases. With solid bus bars I would absolutely compress them to prevent looseness and hot spots at the terminals. I'm sorry that I did not take photos of the assembly of the unit. The battery box is all but hidden. The 10X tape link: www.amazon.com/FiberFix-Stonger-Bearing-Untearable-Resistant/dp/B01H2SH92Y/ref=asc_df_B01H2SH92Y?tag=bingshoppinga-20&linkCode=df0&hvadid=80401840125272&hvnetw=o&hvqmt=e&hvbmt=be&hvdev=c&hvlocint=&hvlocphy=&hvtargid=pla-4584001418376754&psc=1

[@pierreqiu8147]

@@kimmer6 hi, thks for all those useful information,👍👍👍👍👍👍

[@pertybluestang]

Seems it might be worth testing individual cells and going back to 1p. 1 cell could be messing up the whole pack.

[@fharbec]

What did you end up doing with this battery? Are you still using it and if so, has it continued to work ok?

[@SolarEngineering]

sold it for a few hundreds, didn't use it

[@janosvarga962]

Couple questions. Why didn't you arrange the cells with the smaller sized side ? Fixed circular holes can overtension the connector and break them when bloating. Is the compression wo torque measurement ?

[@SolarEngineering]

Because I want to test if compressing cells would recover any capacity.

[@janosvarga962]

@@SolarEngineering no it won't significantly, but will increase the cycle life of the pack.

[@steveclunn8165]

When Testing batteries there are many factors. U may find that the ah goes up a little on each of the next 10 cycles. Slow charging and discharge also gets more ah. A few more cycles would be interesting.

[@SolarEngineering]

will do another capacity test later

[@steveclunn8165]

@@SolarEngineering testing batteries can go on and on. You could uncompress half of them and then do another 10 Cycles and see where that uncompressed half compares to the compressed half.

[@anobody5708]

Get ready to get attacked by the internet experts lol

[@SolarEngineering]

haha, bracing myself :)

[@AlexTorres-qv3hv]

TG found this video b4 buying those, now it makes sense why they are selling these free shipping...

[@SolarEngineering]

I feel like the seller built reputation by selling good cells, and now they just started to scam people.

[@irfansensoy5901]

Hello. I bought 16 EVE brand 280ah cells to make a 48v 280ah battery pack. I also bought JK BMS, it also has other connection equipment. However, during the final assembly, I could not decide what I should put as an insulator between the cells. They install epoxy sheets in commercial products. I don't have any epoxy sheets. I am thinking of using corrugated (cardboard / cardboard sheet etc.) for both insulator and heat ventilation, but I do not know if there is a fire risk in this. As long as there is no arc or heated cable, I do not think there will be an ignition due to cell temperature. Because if that degree of heat is released, the cell is already dead. WHAT IS YOUR ADVICE?

[@johnnycagiva737]

I had the same problem with Aliexpress they sent me grade b cells even though the ad said grade a. The only options I was offered were a discount or send it back at my own expense. This is definitely cheating for me but what can you do? First of all, I gave the app and the seller a bad rating. Then I resold the cells as grade b and luckily I got plus minus zero with the discount.

[@SolarEngineering]

I did the same - 1 star rating for the product.

[@The-Wise-One]

Hi. Great Video, can I please ask if 2 to 3mm Battery Seconds is alot and if it's a concern...

[@MR-ub6sq]

Hi! I see you used some kind of inductive load in the discharge test. How accurate is your consumption measurement with an inductive load compared to discharging with a resistive load? In my opinion, any cheap consumption meter is not necessarily close to accurate when the consumption takes place with an inductive or capacitive load.

[@Mike-01234]

If you use the same load for both tests should be the same. He got recycled cells probably see re-lasered QR codes an old one under that plastic top. Compressing a swelled recycled batteries won't fix the problem they are recycled likely been used for streetlights in China what I heard. These companies go around and replace the battery sell it to a 3rd party who puts new plastic on them re-lasers the QR sells them as Grade A batteries to Americans.

[@amiryazdani4902]

Thanks for the interesting video. I was wondering what is the insulation material you use between the cells.

[@SolarEngineering]

it's just thick paper.

[@gjsxnobody7534]

I always see these with the terminals facing up. could these cells be rotated 90 degrees toward the camera direction.

[@SolarEngineering]

It's better to check with manufacturer. cells that I'm using can be positioned as you described.

[@MiniLuv-1984]

I wonder if the slight increase was due to charging and discharging rather than compression? If you could be bothered to charge them again and check the capacity without compression?

[@SolarEngineering]

will try

[@miquelmah]

how they work after 1 year of use?

[@SolarEngineering]

I'm not using them.

[@nielsdaemen]

If I buy supercheap aliexpress cells, I will expect them to have just 80% of their rated capacity, so just order more than you need, but it's still much cheaper than buying grade A cells

[@leathermanmultitoolsseller5109]

Can anyne please explain? What is the point of compressing, if in this case eventually it will most likely lead to blowout safety valve on the top of the cell (instead of inflating the cell)?

[@vladimus9749]

Squeezes out bubbles that become permanent and reduce capacity but must be done before first use

[@GBCobber]

For the price these cells are a steal. I got lucky I guess. Mine look brand new and the sides are actually a little concave. 8 x 280AH, same as your. Paid under $870 USD ($1200 AUD) shipped my door in australia. $110/KWH is a bargain even if they fall well short of their claims. I'm a remote power system sparky from way back and used to do all this with lead acid, which even now are still over 3 the cost per watt. And this is China dude. Ya pays ya money and takes ya chances. You know that. ;)

[@SolarEngineering]

I understand what you are meaning, but I would like to get what I pay for. Otherwise, it's just a game without rules, where the buyer is going to lose.

[@MarcHelfrich]

Hi there, what are the dimensions of your custom bus bars? Especially the thickness. What would you recommend for a 16S 280AH system 1C. Thank you.

[@SolarEngineering]

I think I got 0.125" x 0.75" Copper Rectangle Bar 110-H02. purchased from here: www.onlinemetals.com/en/buy/copper-rectangle-bar

[@NIEPSEN]

950$ for 8 cells of 245Ah is not a bad price. It's cost you 0.49$/Ah, and the average price is 0.53$/Ah.

[@baymax5440]

you should also top balance and see the result.also if your gonna compress the cell you should atleast have clearance on your bus bar as it will tear those contact.

[@SolarEngineering]

cells were balanced. thanks for the suggestion.

[@marktheunitedstatescitezen185]

What kind of inverter are you using for the 560AH per battery now ? I’ve been told by POWERMR inverters to get MPPT stronger inverter then GVW is so post to be a weaker inverter !

[@SolarEngineering]

Renogy 3000W amzn.to/3OTQ5Kw

[@marinetrax]

Hi, i just bought 16 brand new grade A Eve 304 cells. I want to have the same setup as you but two rows of 8 for 16s block for 48v system. What Nm should I tighten up the nuts on the 4 threaded rods to meet Eves recommendation. They dont specify how to do it. Thanks so much.

[@peter572]

I think the specs recommend 300Kgf. Too tight is as bad as no-compression. I am thinking of adding a spring to the rods or some soft material in between the cells. Any ideas?

[@coreybabcock2023]

My battery setup is 200 ah plastic encased prismatic cells and no compression they are just put in a plastic box and I use a 200 amp Daly BMS too plus renogy 500 amp battery monitor

[@michaelw3809]

I think you have to add the compression before the cells swell

[@coreybabcock2023]

I have a 2p 4s 400 ah setup here in my camper van

[@MickeyMishra]

there are two things I won't buy from AliExpress one of them is a cell phone and the other one is use large batteries or any batteries in my experience. also anything that requires you to have it reviewed by customs.

[@jjs718]

Just an observation, you are not really compressing the batteries correctly with those metal bars at the top. The holes you drilled need to have wider range to allow compression. Refer to the bars sold on Amazon and Ebay.

[@coreybabcock2023]

Where you get that copper flat bar from ?

[@SolarEngineering]

purchased copper from www.onlinemetals.com/

[@5885ronny]

Super Akku habe auch so was 🤗👌👍

[@J.DiPietro]

Can you post a link to that ammeter you were using to conduct the test?

[@SolarEngineering]

here you go: amzn.to/3F0PXTZ

[@J.DiPietro]

@@SolarEngineering thanks. I picked one up and I love it. I discharged the batteries completely and then charged it and found my batteries to have a higher than rated capacity (294Ah vs 280). I realize that the 280 would be at 280 amp discharge but i don't really have huge draws like that so it seems more realistic for my usage.

[@SolarEngineering]

@@J.DiPietro wow, you are lucky! glad to hear that you got good quality cells.

[@derekbeckett7071]

What do you do use for insulation between cell?

[@SolarEngineering]

just thick paper.

[@ibrownbear6531]

Интересное решение против вздутия ячеек. Они реально дуются при зарядке :-( Надо будет так же на фанеру и шпильки посадить, возможно лучше перед этим разрядить каждую ячейку отдельно до 2.5В, тогда мне кажется проще корпус выпрямить.

[@SolarEngineering]

я в итоге добавил сверху и снизу ячейки проставку в 1мм, и затянул шпильками. 1мм позволит ячейке в центре расширяться при заряде/разряде но при этом ячейки зафиксированы и нет нагрузки на контакты там где басбары стоят.

[@ibrownbear6531]

@@SolarEngineering а шпильки какие, 6-8 мм?

[@SolarEngineering]

@@ibrownbear6531 6мм, ужали без проблем.

[@ibrownbear6531]

@@SolarEngineering Спасибо

[@munirzangana3594]

Is it possible to connect 32 cells With 16 cells in two parallel groups That is, summing all two cells parallel to each other Complete with a 51 volt system Any breath, 51 volts Note with the use of one bms

[@SolarEngineering]

yes, checkout my latest video. I have battery 3P16S

[@munirzangana3594]

@@SolarEngineering Thank you for the information But why don't we notice it a lot, especially in its great capabilities, unlike the Package Parallel separately?

[@SolarEngineering]

@@munirzangana3594 almost every EV has cells in parallel.

[@johnflynn6140]

So Don't buy these batteries and if you do make sure the seller is selling grade A cells which seems to be hard to find, Aliexpress rip-offs cause like you said no one is going to return them

[@CL-yp1bs]

Copper on the aluminum terminals will cause galvanic corrosion

[@greegearl1542]

Aliexpress is not a very reliable place to get batteries anymore. If you make a purchase from a dishonest seller you may end up getting ripped off. It happened to me.

[@ThomasOrdon]

No you should not do this this is actually very dangerous first of all reasons one they expand for a reason to when you compress them You're also increasing the pressure inside each one and when one continues to swell right next to another one it compresses the other one and once a cell is expanded and you try to compress it you actually can create a thermal runaway and issues the best thing you can do with cells like this swelling or not is liquid cool them cuz you keep yeah you don't want to do that they expand for a reason it's not just that they're guessing it's that they're gassing and creating an air gap where there could be an issue so yeah don't do this

[@raphofthehills4405]

Yes and no. Some manufacturers, like EVE, recommend compression (300kg) on some models (like LF380x) to increase the cell's life (from 2500 cycles to 3500). That's in the datasheet. So yes adding compression increases internal pressure, but no it is not necessarily a bad thing as long it is done correctly and on the right type of cells (some prismatics & pouches, per supplier's specs).

[@DANIEL-ls5ku]

I don’t get it, what’s the total “result”???

[@SolarEngineering]

Test params: Cells charged to 3.65V (till 100mA) Cells discharged to 2.5V Discharge current 75A (+-4A) / 0.13C rate Ah before compressing - 480 Ah after compressing - 488

[@DANIEL-ls5ku]

@@SolarEngineering I see, much appreciated 👍🏼

[@mylittledetour]

Have bought Grade A from Liitokala and received Cells with no QR Code... Can't be Grade A.. Same procedure : send it back from Al and send it back from Paypal !

[@Chrissi33004]

Alternative title: how to trigger the overpressure release valve 100% on grade B cells

[@SolarEngineering]

)) good one

[@kimmer6]

@@SolarEngineering Can you please tell me if my Grade A cells look bloated? See burst discs...... 2 of 4 gone. kzbin.info/www/bejne/gobLfKCXic-mb9E

[@SolarEngineering]

@@kimmer6 😂 just a little bit, what happened to the cells?

[@SolarEngineering]

ah, nm, read the description.

[@kimmer6]

@@SolarEngineering My brand new power supply arrived defective. It did not hold the voltage setpoint. It ran for a week top balancing 12 cells but made little progress. I disconnected 8 cells and put the leads on 4 cells. This happened overnight. The replacement power supply works as it should. Its an expensive mistake.

[@5885ronny]

🤗👍 Super danke 👍👍🤗

[@SolarEngineering]

you are welcome

[@PavolFilek]

WHat pressure do U use and why ? Why U use BMS to disconnect battery ? If BMS does that, your MPPTs will be dead. Also some inverters. BMS is for monitoring and signaling statuses to MPPTs, inverters, or monitoring like EPS32, Arduino, Venus OS and so on, and in the situation, that needs intervention, your system should disconnect panels first, then shut down inverters and than shut down battery packs.

[@Stucc0Dude]

In order to keep them from potentially leaking in the future, would you recommend putting them end to end instead of side to side?

[@SolarEngineering]

I'd recommend fixing cells to remove any movement and remove stress from busbars. Going to build a pack soon and record it.

[@Mike-01234]

The information you're stating that in order to get a refund you must return them to China. The cost of return based on weight alone exceeds the value of the item needs to be made more known. I see many new people buying from China who think they can get a credit card to refund it's not correct. You would think they would have more pull over Chinese Company in reality they make lot of money in China not going to push them to refund because of shipping costs. What I'm seeing is recycled batteries they put a new covering over it and re-laser a new QR code in the top. If you can show your credit card company that it was a scam they might refund without the return.

[@Solovey23]

What's the name of the seller?

[@SolarEngineering]

"liitokala Official Store"

[@igorkvachun3572]

Yes Akb LiFePo4 🔋 ⚡ 👍

[@agmkvm8005]

To be clear: the manufacturer specifies more cycles, not a larger capacity of compressed batteries. So, the experiment is interesting, but neither proves nor rejects the effectiveness of compression.

[@Sol_y_Sombra]

Bonjour, je pense que votre test n'est pas significatif. Car je pense que l'impact de la compression est évaluable à long terme sur des batteries avec un grand nombre de charge et de variation de température. Cordialement.

[@my_carp_life3424]

Did you get your money back?

[@SolarEngineering]

Seller denied return and Aliexpress stayed on the seller's side.

[@waynewilliamson4212]

I was liking this, but I think I missed the results....let me rewatch and see....

[@waynewilliamson4212]

yup, your just telling me 488 amp hours. you realize without the volts that is useless. You need to do the watt hours vs watt hours...just say'n....and no, I'm not going to watch again....

[@alexanderandreev7151]

Мда, ну и подства, просто выкинул деньги. Они даже если и маркируют А, то через месяц-другой всё равно вспухают. Проще купить какую-нить сборку на batteryhookup, они хотя бы сразу пишут, что это БУ.

[@coreybabcock2023]

I have that same renogy inverter charger 2000 Watt I paid 425.00

[@SolarEngineering]

nice, mine works fine so far.

[@jgbelmont]

Why would anyone think Aliexpress is a good company in the first place? Just buying from them in the first place you are taking major risks!

[@hoptoa]

You are from Russia? You have a very strong Russian accent.

[@SolarEngineering]

not from Russia.

[@Lunas2525]

Ship it cod.

[@rickard1802]

There is a world of difference between different grade B cells btw. Grade B just means factory rejected them because they didn't meet all criteria to be able to keep factory qr code and factory warranty. If a seller claims it is grade A cells it is very bad tho and a blatant fraud. I have 40x grade B Rept 280ah cells bought from donguan lightning. They where never advertised as grade A (or grade b) but was advertised as new wich is most likely true. I have 32 of my cells in a 2p16s battery which i can draw 30kwh from which is 293ah from all cells. No bulging. The 8 remaining cells where 288ah or more. Im not sure why factory qr code was scratched but for use as energy storage my cells are A+++++++ lol. Maybe for use in EV it is not good enough i have no idea

[@SolarEngineering]

thanks for the information. In my case seller didn't claim it's a grade A (nor B).

[@rickard1802]

@@SolarEngineering Still..85% of rated capacity is bad :(

[@ОлегЛюдина]

Давай все то саме, але нормальною;) мовою

[@trevornelmes9331]

That really sucks. If you expected 290Ah when new on those 280Ah cells (as you should for new Grade A), then more like 85% capacity. My REPT cells are on their way, along with the BMS, so we shall see what arrives.

[@SolarEngineering]

please keep me posted, curious about cells.

[@EUGENIUCALMIC]

dont buy chaina sheet !!!!!!!!!

[@Ikono-claste]

chinese are often border line honest, I hope the ones I receive of Liitokala will be in better condition than yours

[@SolarEngineering]

that's true. I hope you'll get a good cells.

[@onthelake9554]

Like putting a seat belt on after the car crash , it won't help now.

[@pavelsedov9982]

Ужасный английский с русским акцентом! Довели рассейских блогеров😢😢

[@1BrockSawyer]

Oh I forgot there is a rule of compression using inch-pounds of torque per size of cells and not sure what it was but if you look you will find compression ratios in the manufacture literature and it isn't enough to reshape cell so be careful how much compression you use! There are folks who have done cycle comparison on compressed vs non compressed and difference isn't that much?

[@ursodermatt8809]

well, any compression is better than none for longevity

[@calmeilles]

LithiumSolar discussed this a couple of days ago. The manufacturers specs give a compression figure and seem to be saying compression is good. But his conclusion was that for particular his use case avoiding deep discharge / high charging cycles is likely to gain as much in useful life as the manufacturers claim compression would. His video: kzbin.info/www/bejne/q4vIZ3V6q7yDnKs

[@neliosamch3195]

You can't compress them more than 12 pounds per square inch and still need the space for expansion and contraction. Some of my battery pack have been getting more capacity after several charging and discharging cycles. I always said that lifepo4 chemicals is. Just a little bettter than lead acid one and over priced, so the best thing anyone can do is do not spend the money they don't have because they will be very frustrated with these cells.

[@ursodermatt8809]

ok, stick with your lead acid technology then, now worries

[@williammchugh4361]

You can only discharge lead acid to 50% capacity if you want them to last. Which means you will have to add Even More lead acid batteries for the same capacity. Even with that, LA still can not cycle nearly as much before they are dead. Another issue is lead acid can not be charged Nearly as fast. Another issue is lead acid takes a tremendous amount of time to top charge to 100%- upwards of 10 hours in some chemistries. This is not coming from a lithium snob, I’ve used lead acid a lot with solar. it has been a complete pita. I have barely used this small system, yet I’ve replaced the lead acid batteries I think three different times. The current batteries, a set of heavy duty 6 volt flooded golf cart batteries are well on their way out after five-six years. That sounds like a lot of time, but it isn’t when these batts have barely been cycled at all! These are The Last lead acid batteries I’m going to put into this system. I’d hate to think of the headache of using LA for something much larger like a real power wall. Jeez.

[@marktheunitedstatescitezen185]

You should have 560Ah for the 8 cells paralleling every 2 then in series for 4 cells - let me watch you’re actual test !

[@vevenaneathna]

scum, yes.. should have shipped them 100 lbs of bricks on the slowest boat shipping known to man, got the refund and closed your account after leaving a nasty review with pictures. ur too kind

[@bako1200]

Ну и нахрена это надо????? Реклама китайского гавна???

[@andrewtitoff6167]

По русски нельзя было что-ли?, твой английский даже нейросеть не понимает...

[@SolarEngineering]

иди своей дорогой

[@PacoSS67]

Please, never do that 4s2p series. Allways do 2 x 4s1p each one with their BMS. Cells must be controlled individually.

[@SolarEngineering]

could you explain why?

[@ilsonbob]

Don't worry about it. The parallel cells will always be at the same voltage

[@FatgirlMickey]

So have u bought grade A cells and tested them to see if they're pulling capacity?

[@SolarEngineering]

I did purchase grade A cells before, my bigger bank contains only grade A: kzbin.info/www/bejne/iHPCgJJrhdWpbck

[@Чаклун]

Лет ми спик фром май харт

[@2ClicksUp]

Glad you did this Vid. Prefer if you were more direct - I walked similar road via Alibaba. Neither the Supplier nor the Vendor takes responsibility for corrupt products not financially worth returning. Tried a 2nd Supplier and backed off before giving them my money. Now I'm at point where I refuse to deal with Chinese mentality and really hope for another Country to offer LFP and BMS.

[@guysgt5003]

Absolutely correct my friend you are an intelligent person. Thank you for chiming in

[@eyeswideshut2800]

Didn't Prowse recoup from Amazon recently on bad cells from China? Shipping has gone up exponentially so bad deal.

[@kevinmills5293]

I’ve been burned twice when dealing with Chinese suppliers. I’ve asked for samples from potential suppliers but of course they refuse so I won’t buy any cells from China now. As he says in the video, it’s legal scamming.

[@carmichaelmoritz8662]

i bought four brand new 12 volt lead acid batteries for my 48 volt mobility scooter and they lasted one year use before one failed. i could go three days of short travels before a charge was needed. i now bought used headway cells and thats something i will never do again. even at 80 percent life they still only last about ten minutes before they start to drop to the point where the scooter shuts down due to low voltage. and the price of new compared to lead acid , i will stick with lead acid even though they weigh way more. almost 600.00 lost that this poor disabled person will never get back. very disappointed.

[@claesmansson9070]

Think it s important to fix/compress cells before starting charging on them,even grade a cells will swell 1 mm, the reason for compression is that you should get a 1000 more cycles out of the battery in total.Ray builds cool stuff has made a video on who you should be able to trust of the sellers in china,think her name is Jenny, but you can find the video yourself.

[@teagueman100]

They are supposed to be compressed before they swell not after.

[@jasonwarren781]

They came swollen, he didnt cause them to swell

[@theanonymous6289]

Great video. Thanks for taking time to post it. We're all in this LiFePo4 mess together.

[@SolarEngineering]

thanks!