Remember never to add anything to your own shell. Chinese electric bike is expensive, so we need to take good care of electric bike. Once you remove the shell and add it to disturb the density inside, even if the repair shop equipment is very advanced, you can no longer extend the battery life, only for a short period of time to add capacity, if the drum shell battery is mostly of no repair value, only a day-to-day.
But the charge, no electricity, no drum, the use of good quality charger, is an important factor in prolonging battery life.
Buy battery choice capacity, never drum shell, multiple protection, high-tech patent battery is the most important reason. Recommended use of electric bicycle batteries.