dead battery

Yeah, you are starting to be a voltage junkie like me. If the controller in the MP3 is like my MP2s external controller it will shut out anything over 60v so you cant hurt it and its as high as you can go with it. The old cheapie 48v controller will tolerate 62.5v and it only has 63v caps. Its days are probably numbered.

Dunno, over at the Sphere there are many high mileage batteries like 5K+. Read a thread by a teacher in LA that commuted 50mi almost everyday of the school year for years on a Ping battery, as well as RC lipos. According to him he abused the Ping and it came back for more. The lipos werent as forgiving.