Along with the development of new materials, the emergence of new technology, the more advanced and durable rechargeable battery also arise. The new development of the solid polymer (polyelectrolyte ) Li battery, Li metal battery, not only solve the problem of liquid leakage, and a battery of greater capacity, smaller volume, more safe and reliable. They will become extremely has the potential of a new generation of battery products.

18650 Battery are susceptible to overcharge, deep discharge and short circuit damage. The single lithium ion battery charging voltage must be strictly restricted. Charge rate is usually no more than 1C, the minimum discharge voltage of 2.7～ 3.0V, such as continue to discharge will damage the battery. Lithium ion battery with constant circulation constant voltage charging. Using 1C current charging to 4.1V, charger should be immediately transferred into constant voltage charging, the charging current is reduced gradually, when the battery fully charged, enter a trickle charging process. In order to avoid overcharge or overdischarge lithium ion battery, not only in the inner is provided with a safety mechanism, the charger also must take safety protection measures, to monitor the lithium ion battery charging and discharging state.