I thought before wife uses it, I would test it. Got to doctors OK, down hill, on return did steepest bit, just, then when I thought now plain sailing brakes went on and realised no power, so pressed the 40 amp reset, no joy, so disengaged the brake, and pushed home. I tried a number of times to see if 40 amp reset would bring it back to life, no luck. So split into the 5 main parts and carried down to flat under house. This morning opened one battery case to check battery voltages 12.4 volt each, reassembled scooter and all works. As to what was wrong not a clue, can't see in the instructions anything that auto resets, so rather uneasy using it, in case it fails again. Could be as simple as one of the multi connectors not making. But pushed it 1/2 mile, would have expected any bad connection would have made, and with brake off, and ignition on it would have screamed at me.
My wife used to have the same model and had the same problem. First thing I found was that the battery locking pin hadn't been reinserted allowing the batteries to move around and also the contacts in the base of the scooter were quite corroded. Cleaning the contacts and inserting the locking pin seemed to cure it.