Swollen LiFePO4 battery cells... are these dangerous??

Рет қаралды 9,510

Күн бұрын

Пікірлер: 47

@mathewemy 11 ай бұрын

I put 4X 60ah slightly swollen cells in parrell, as delivered from LiitoKala. To replace a failed 130Ah winstone cell in a 16S string runing at 55V (3.45 a cell) in Aug 2021. (A small amount of clamping when installed, G clamp). The were cycled daily (melbourne) with a therotical peak charge of 36amps but realistically around 22amps due to diffrent orenations of the panels. Load was a 4Kw peak inverter. JK BMS only balanceing if any cell gets above 3.45 Took them out of service yesterday. Now horribly swollen, trying to take the preasure off the G clamp was a huge effort. That is what happens to out of the box swollen cells.

@justinmurphy2227 2 жыл бұрын

It's been 5 months and I was just wondering the status of the experiment. There is a LOT of us that have opped for the cheaper version....that have swollen. I would love to see what pro has determined over almost half a year.It would greatly help many!

@rcinfla9017 2 жыл бұрын

I believe the 304 AH cells are pre-lithiated anode cells. They do often swell a little especially if charged too soon after initially assembled by manufacturer. Pre-lithiated cells eliminate the long traditional charge forming process and consumes less of the cathode lithium yielding a slightly greater cell capacity. It reduces the manufacturing cost of the cells. You likely did them no favor by leaving them fully charged during the initial early life before SEI protective layer growth has fully developed. Regular cells done with traditional charge forming process also produce gas during SEI charge forming growth process, you just don't see it because manufacturer relieves the gas before finally sealing the metal container. The metal container is the cell seal. The actual cell laminate wraps are open at the top to allow easy foil terminal exit from wrap. The gas bloating just inflates the metal container, the actual unsealed cell pouch wraps do not bloat. It is caused by electrolyte breakdown when SEI protective barrier is not yet fully formed and the degrading aspect is not the gas. It is the other decomp tar components that clog the electrode pores raising cell impedance slightly. A little bit of bloating does not do significant damage. Eventually the gas will escape the plastic terminal grommet port seals in metal case. You can squeeze them a little to accelerate the gas escaping, just don't over do it as you could cause the overpressure vent port to burst if internal pressure gets to great.

@offgrid_power 2 жыл бұрын

Thanks for the detailed response! :)

@StephaneGuayMCB 2 жыл бұрын

Thank you. If I understand, buying Chinese prismatic cell brand new, grade A cell doesn't mean it's is bad if they arrive a little bit swelled.

@BlueSky-cy5nw Жыл бұрын

Is there an update coming on the condition of these cells as of today?

@SkypowerwithKarl Жыл бұрын

They will be fine. If you put them in a fixture with spring compression with 500 to 600 pounds of force evenly distributed across the wide face. You can then expect 5000 to 10000 cycles with 80 % depth of discharge or 15 years. This would have to happen before the first full charge or top balancing. Without compression they may swell a bit more, and it’s a bad idea to then compress after they have done that.

@ev-olution8597 23 күн бұрын

Never store fully charged or fully discharged cells for several months without use. This causes offgassing inside and increases internal pressure, which leads to swelling. Always store cells charged between 40% and 70% and check the voltage every 3 months. Slightly compress them and cycle them by charging and discharging them several times, this will reduce the swelling. If you want really to know if cells are degraded or damaged, test internal resistance instead of measuring gap between stacked cells. In most cases if cell degraded to the point it is useless it develops internal current leak which discharges cell while it is stored.

@thatonebeone 2 жыл бұрын

id use them...just keep an eye on it depending on the types of use if its high amp charging and dis .. if its low amp use i would not worry much

@offgrid_power 2 жыл бұрын

Thanks for the advice!

@Karlosr6 4 ай бұрын

What will happen to the cell if its casing has a micro leak?

@krg038 2 жыл бұрын

I use grade B cells. Bloated. Less capacity but within the good price per watt. 280ah actual 250ah.. About 1800 cycles charge/discharge now.. Still going. I do .1C charge/discharge 80/20%. 48v 16s. Discharge to 2.6v put them in the fridge. The bloated is permanent. Room temperature charge to 3.65. top balancing. Good to go. On my 3rd pack now diy jkbms. Just tape compression. Grade A will swell at 3.5v not bloat.

@offgrid_power 2 жыл бұрын

Thanks for the advice! :)

@mr_scruffles_ytminecraft1110 7 ай бұрын

When wanting to go the cheapest route with soemthing ask yourself this before doing so. Will it effect my health or condition of my overall way of living (aka cause a fire or something along those lines) ? Is it going to be safe? How risky is it to have?

@The-Wise-One 2 жыл бұрын

Just purchased some grade b, was told that we're just cosmetic defects and not bloated. Arrived bloated, appears 4 out of 8 are better, 4 worse with lower voltage, questuon, is what amount of bloatness is ok with these cells?

@effbee56 2 жыл бұрын

This sounds like a worthwhile experiment. Cheap may be cost effective if the product cost vs lifetime output is good. Good cheap PV panels costing 60 percent per watt vs the most expensive premium brand over 25 years may be the better bet. Maybe the cheaper batteries will also prove cost effective unless their effective number of cycles is much less than the premium brand. If they failafter a few years you have the excuse to upgrade to the latest technology.

@offgrid_power 2 жыл бұрын

Yeah exactly. There are good price per wh to be had in grade B/second hand kit. Especially panels and cells. :)

@StephaneGuayMCB 2 жыл бұрын

Why a swollen battery is bad?

@krg038 2 жыл бұрын

abnormal gas internally. cracking. charge/discharge cycles reduction.

@offgrid_power 2 жыл бұрын

👆🏼👆🏼👆🏼

@temp911Luke Жыл бұрын

It has power to destroy the whole New York city.

@jackiedines5229 2 жыл бұрын

They are overcharged, over and undercharging is deadly for these batteries!

@offgrid_power 2 жыл бұрын

Thanks for the advice. :)

@NaeimAlaagibnaeim Жыл бұрын

Ideal setting bms over voltage 3.4 and under voltage 2.8 volt ? If that why bms manufacturer set bms 3.65 and 2.5

@1quickdub 2 жыл бұрын

they should be charged to 50% of capacity for storage

@offgrid_power 2 жыл бұрын

Thanks

@todamnbad 2 жыл бұрын

no one seems to be able to answer my question so hopefully you can, I have some "new" cells that have some minor swelling around the anode and cathode which isn't a huge concern but my concern is that some of them have what appears to be a white frost like spot on the clear cover on the vent, the spot is on the inside part of the vent cover, do you have any idea what it could possibly be?

2 жыл бұрын

Hello, it appears that i've simmilar issue and i've made some mistakes while doing battery maintenance/handling last months - I'm the guy who bought cells, left them away for some time and put them to van, as you mentioned in video, lol. I have 8x EVE Lithium LF304 (version B). Seller have sent them to me charged to 70% SoC and checked capacity before, they were little more 304AH as far as I remember. I've top charged them after they came to me and put them into my van without compression fixture - I didn't know that time it's important. Cells were stacked next to eachother and i've only created frame for 8 cells, so they were not moving (or at least supposed not to do it). They were sitting down in van from May to beginning of July. When I started van upgrades again in July, I've realized that 2 of them are little bulged, but cell's datasheet says that they can be +/- 1mm and I ignored it. After connecting BMS and other parts, I was using them almost 2 months till few days ago BMS disconnected and I saw that all of them are bulged as on your video and one cell was discharged to 2.4V - it was probably reason why BMS switched off. Other cells were 3.2V or something, but totally debalanced. I realized that that I made bad voltage meter / balancer wires connections and few of them was loosy/disconnected. Also cells are scratched all over, in some places to aluminum case - clearly visible that it came from vibrations while riding. I was using cells with Daly 150A BMS and biggest load was 2,5kW inverter - used occasionally sine there was nice weather, camping connection etc. Maximum charge current was 20A from 230v>24v charger and about 12 - 18A solar mppt charger. I will make compression fixture and upgrade my battery mounting, so they will not move at all. I won't squeeze them hard. Also I plan to put some material between cells, so i wont compress back already bulged cells. I will measure individual battery capacity soon (need better equipment). Also I have some questions : 1. Please tell me, are swollen cells presented on video EVE Lithium LF304 - evlithium.com/LiFePO4-Battery/eve-lf304-lifepo4-battery-cell.html this ones ? 2. My cells were top charged by me with 3.65V ,but after disconnecting power source, they resided at 3.39V. Why you had 3.5V and greater values? Are those different cells ? 3. Will you guys compress cells back to "original state", so I would have to do it with a lot of force or a just enough to exclude grinding between cells ? I plan to do the latter solution with some additional layers between cells, but i saw some videos of guys compressing back B-grades to original width. What is your opinion ? 4. Since aluminum case are connected with positive pole, do you guys think that cells could lost current/discharge/short it self (however to name it) and it could also lead to debalance battery pack ? I will keep you updated, best wishes!

@nzdatsports9659 2 жыл бұрын

Yep the way overcharged for storage capacity 70% is optimal.

@offgrid_power 2 жыл бұрын

Thanks for the reply.

@eelbatteryofficial 2 жыл бұрын

there is no 320Ah actually, only 302Ah and 304Ah, need to avoid such 320Ah even 400Ah cells they advertised!

@offgrid_power 2 жыл бұрын

Good advice. :)

@HaroldMcDermott 6 ай бұрын

That's normal for them to swell they all do it, The electrons move under between the plates making expand then as cell discharges it gets narrow again, nothing can stop that you could squeeze them together but when it charges back up it expands again so why bother squeezing them just made more cell movement.

@welshnutterz 2 жыл бұрын

I believe if they are CATL cells they can be swollen from new

@offgrid_power 2 жыл бұрын

Yes, they can!

@mikesgarage394 Жыл бұрын

If you had stored them properly -vertically, it probably would not have been as extreme.

@davidkettell6236 2 жыл бұрын

i never charge my cells that high ,it is unnecessary

@offgrid_power 2 жыл бұрын

What voltage do you charge to?

@davidkettell6236 2 жыл бұрын

@@offgrid_power 3.4 do you follow off grid garage on you tube .Andy is a lot of fun.

@hedleypepper1838 4 ай бұрын

They pretty much all come fro china 🇨🇳 even usin USA 🇺🇸 or in my case UK 🇬🇧 suplier you are trustng their china supplier but you are probably paying a lot for your local guy to check and test the celks for you . Pay your money and make your choice.