Tonight, I go to bed victorious!
Finally had time to do as
@sunshine_eggo and others suggested. Set my inverter to 56V. Charged up cells one by one. I also rebalanced the cells in the other battery as a few looked like they needed it.
Now it looks like some semblance of balance has finally been restored! Both batteries appear to be discharging at *roughly* the same rate now. Going to run a discharge/absorption cycle now and see how they look after that.
A quick root cause analysis for anyone interested (or in the same boat):
- Poor connection on the lead between cells 1 and 2 caused erratic voltage readings on the BMS
- This threw everything out of whack as it was constantly registering cell over/under voltages, and eventually the battery was way out of balance
Solved by a relatively simple albeit tedious rebalance. Thanks to everyone here for the help!