So… I honestly have no idea what happened. This is a 120ah build of cheap aliexpress cells and a overkill BMS. I use a red arc 1225 charge controller to manage the 100w solar panel and alternator/starting battery To keep the cells charged. They have worked flawlessly for a year with delta...
This happened to me a few days ago after a year of zero issues in my van. It literally exploded with audible explosion. No open flames but it was bad. Only one cell was damaged and BMS measured ~3.4v when it happened.
I’m guessing this is a possibility, thst the blue film wore through somewhere and short circuited… maybe? Cell voltage was 3.4 when it happened and dropped from there. I never blew a single fuse anywhere in the system and none of the wires had any wear or melting exc