[hartvige]

I got bitten by this issue yesterday and ended up with a dead Segway, even though I had been trying to follow the discharge state of the batteries by regularly powering on the segway and checking the charge level on the InfoKey. Fixed it by manually (external power supply) charging the rear battery to around 65V (it was around 10V initially), then sticking it onto the SegWay and letting it fully charge there.

However, I got an idea for improving the segway which I wanted to float here. The idea would be to modify the machine so that the radio board is powered through two diodes, one from each battery, instead of being directly connected to the rear battery only.

This would provide many benefits. First of all, it would mean the batteries (when idling in storage) are balanced by the quiescent current of the radio board - the battery with highest charge will supply the radio alone until they are even, and then they will in parallel supply the radio from there on. Secondly, this means the InfoKey battery indicator would (if monitored every month during storage) show the actual state, allowing one to recharge the batteries regularly, trying to keep the charge around 50% to maximize battery lifetime. Thirdly, if forgotten, it will now take the radio board twice as long before fully depleting both batteries.

Any comments/suggestions?

Does anybody have schematics or wiring diagrams, or is it easy to find the connection path from the rear battery to the radio board (and the optimal interception point) once you start poking around?

A second step that would improve the situation even more would be to add a low-voltage cutoff circuit on the path from the output of the two diodes to the radio board, so that a voltage of 60V or so would completely shut off the power to the radio board and reduce current draw to essentially zero. But this is more complicated to do, and might be unnecessary once the diodes are added and if you remember to check the charge level regularly.