Charging models & the performance of battery packs for electric bicycles

Electric bicycles are becoming very popular in China in the last several years. 99% of all electric bicycles in China use VRLA battery pack as a power source. The cycle life of most VRLA battery packs is much shorter than a single battery's. In 95% of all failed battery packs, only one battery is dysfunctional. Overcharge and over-discharge are the primary factors for the failures of VRLA battery packs. Current charging method cannot guarantee that the batteries do not over-charge or over-discharge. To obtain good performance of VRLA battery pack of electric bicycles, different charging methods were tested. Among the test results, pulse charging methods results was especially positive.