I had a Bionx electric motor fitted to my bicycle. I was told at the time that the battery would last about five years. The motor burned out after less than three years of light use and the battery was dead after about the same amount of time even though it had been looked after very carefully according to the instructions. It was going to cost $1700 to get the motor fixed and a new battery was priced at $1400. This is a terrible company to deal with. Their products are shoddy and grossly overpriced and their customer service does not exist. Do not buy anything from BionX.