Cells survived an accident

[Rosed1000]

Last summer I built my own 12v 280ah battery and compressed it between two pieces of pressboard held firmly by four threaded rods. After an accident where my rig was totaled(pickup rammed us from behind), the pressboard and rods were damaged and only half held the four cells. The bms appeared okay (but I’m really not sure it is). The blue cells have several white marks on the blue casing, but it appears that they are not leaking. After the wreck, I just stored the cells and bms on a self in my garage.

Obviously, I would not want to discard these if they are okay to use. So I would like to try re-balancing and re-charging them. So I am looking for advice. Is there a leak-safe container I can put them in? I am worried about re-charging without the cells being enclosed safely. I have purchased the wood and threaded rods to once again compress them. Under what conditions would you do this?

Or am I crazy to try this due to danger of explosion. I’ve read on this forum that Lifepo4 batteries rarely catch fire - but I really don’t know what the risks are. All I know is this DIY battery cost me about $650 including the four 280 ah cells (from Docan) and a decent BMS. I would hate to discard it all unless I knew they were hazardous. I would really appreciate your advice, friends. Thank you.

 

[BentleyJ]

If the cells have not bulged or expanded and there is no electrolyte leakage that passes the first test. Next check the voltage on each cell individually, if they are 2.5V or above, good chance the cells are usable.
I would then apply some voltage to each cell with a small bench top power supply/charger ramping up slowly and observing behavior. If the cells begin taking current as the charge voltage goes above resting voltage, another good sign. Keep increasing voltage until reaching 3.5V. When the current falls off this is an indication the cell is fully charged. Let the cell rest with the charger disconnected for several hours and if the voltage holds at approx. 3.35V then you have a good cell.
Lastly, you could load test the cell but would need a way to pull 25 to 50A from the cell while testing voltage drop. This is probably not necessary if the above is OK.

 

[Rosed1000]

Excellent advice. Thank you so much!

 

[Rocketman]

If you are concerned… do the charging outside.