I have had a cell fail. I just removed it from the string making it 15s - I list a bit of AH but the motors run fine.?
if a BMS were to fail leaving you stranded, just disconnect it temporarily and keep a close look on cell voltages while motoring home to prevent a cell discharging too much.?
I originally had two banks of AGM batteries - completely separated with their own panels for loads and their own charging sources. When I went to LFP I chose to make a single battery pack. This makes life much simpler. And as others have noted, combining two batteries in parallel with voltage disparities can lead to disaster.?
Reuben Trane