First tests are showing promise (and complexity of reality):
pi@GoPi5Go:~/GoPi5Go/systests/docking $ ./docking.py
docking.main(): Test: 0
Undocking Begins
Undocking Complete
Docking Begins
vbatt: 11.54 d(vBatt): 0.374 max d(vBatt): 0.374
Docking: Success
docking.main(): Test: 1
Undocking Begins
Undocking Complete
Docking Begins
vbatt: 11.53 d(vBatt): 0.331 max d(vBatt): 0.331
Docking: Success
docking.main(): Test: 2
Undocking Begins
Undocking Complete
Docking Begins
vbatt: 11.56 d(vBatt): 0.383 max d(vBatt): 0.383
Docking: Success
...
docking.main(): Test: 10
Undocking Begins
Undocking Complete
Docking Begins
vbatt: 11.52 d(vBatt): 0.340 max d(vBatt): 0.340
Docking: Success
...
From here on the sensors used claimed success but no juice connection was actually made:
...
docking.main(): Test: 16
Undocking Begins
Undocking Complete
Docking Begins
Exception OSError: No SPI response vReading:0.00 continuing
vbatt: 11.03 d(vBatt): 0.100 max d(vBatt): 0.100
Docking: Success
...
docking.main(): Test: 19
Undocking Begins
Undocking Complete
Docking Begins
vbatt: 11.01 d(vBatt): 0.100 max d(vBatt): 0.100
Docking: Success
docking.main(): TEST COMPLETE
Appears that just stopping the motors caused average battery voltage to bounce the 0.1 volt threshold chosen as “Docking Success”