I have 4 older purples. I have tried 2 in the past couple days. Fresh off of being charged they don't cut it it any more. The first sign is going up a hill at 80% plus on Power, complete cut out . Comes back on still at 80%+ drive a little more and no/little support in Tour and the bike motoring system just acting funny. When I replace w/newer battery all well. I have 2 more to test but they are all at least 3-4 yr old and well used. It is time to get them rebuilt. Somebody w/skills I don't have should be able to to do this and even better would be a kit I could this with but I doubt it is available. Does anybody have any thought on rebuilds ?