I’ve had an idea for the modules. Could we use the extra outputs to drive a external bigger mosfet and dump load, when say the internal balance resistors cannot cope but before the controller switches off the charge controller via relay.
For example the internal resistors switch on at 3.9v, bigger dump at 4.0v, then controller switches relay at 4.1v to turn off charger.
I also have a circuit that I’d like to try which would actually add active balancing to the modules. It works by boosting the voltage of a cell that is high up to pack voltage then injecting it back into the pack.
Having another pin do this allows the balance resistors to still balance in case of a fault.