

I’d personally stick to a protected cell for projects like this. That means it has an integrated protection circuit that keeps it from being over / under charged, protects you from an explosion if you short circuit it, and provides a temperature cut off.
Thoae generally top out at around 10a, rather than the 30a the cell might be capable of. Still tons of power for OP to work with.
Probably fermenting sugars turning into alcohol.