I inherited a 1000watt E+ bike. It was unused for years and would not charge. I opened the battery hub and charged the cells manually until all were above 1.0V. It then charged normally and has worked well since. I think the NiMH cells have lost a good bit of their original 10AH capacity but I don't have a good way to test. I mounted a volt meter to the bike to monitor the 30 cells. Interestingly, there is miles of power after the E+ battery icon shows none. I keep the voltage under load to 33v (1.1v/cell) and stop using the battery if it goes to 30V (1.0v/cell). So far the safety circuits have not cut in. I checked that none of the cells reversed polarity after a full discharge (30v).

This bike has connectors for a 2nd battery near the seat. Does anyone have a circuit diagram of the wiring harness that connects the battery(s), motor, controller and brake sensors?

I have a couple crazy ideas I'd like to try.

Idea 1. I have a Santana Rio tandem with 26" wheels. I has a 140mm rear axle which about the same as the E+. I'd like to be able to move the wheels and controller from the tandem frame and then back to the E+ in 30 minutes. The Rio is built to carry the weight but it would need a minor modification to the rear forks to handle the thrust of the motor. I'd also need to create a long wiring harness for the tandem. Thanks for providing the source of the Hirose connectors. I found them at Mouser.

Idea 2. I am considering adding a 10S Li battery, connected in parallel with the NiMH battery in the hub. It sounds crazy, but the voltages seem to work. The Li battery would be charged off the bike. The open circuit voltage of a 10cell Li battery is 42V; the OCV of a fully charged 30 NiMH battery is 42.7v. A discharge cut off 30V works for both battery types. I'd avoid directly connecting a discharged battery of either type to a charged battery since the resulting current might be considerable.

I plan to use 2, 18V Makita 4ah batteries in series. I'll use the mounting connectors from 2 Makita tools and a bracket screwed to the bike's bottle mount. I've re-built the batteries using 18650 cells and cases from non working Makita batteries. Sharing the motor's load should extend the bike's range considerably and improve performance.

Anyone see a serious flaw in the ideas?