i2 i2 bms battery diagnostics

[ursoseg]

Greetings.
I'm a retired ee with too much time on his hands.
I'm looking at a used i2 with one good battery and one dead. I can swap them front to back.
With good one in front slot,segway boots with no error code but balance leds cycle and stay all red.
With good one in rear slot, segway boots with E042 error code and balance leds cycle and stay all red.

Is there any way to substitute a 72VDC power supply for the bad battery pack to test whether this i2 will boot all the way and ballance? Or does the segway require a response from the i2c battery communication to enable the battery and accept it? (If the former were possible one could put any 72 vilt battery in the segway battery case .)

I have built an Arduino battery reader as posted at
github.com/martinbogo/i2-battery-diagnostics
I works and reads all the cell voltages, etc, on the good battery, but no communications with the bad one.

I want to see if it works before shelling out for a new battery.

Thanks