1, the service life of the battery, the old battery performance is reduced, the charging can not reach the standard voltage, the charger does not stop, always charge the battery, it will occur hot situation.
2, the charger model is too large, the standard charging current of the charger is higher than that of the battery, which accelerates the heat energy generation of the battery, and forms a hot state.
3, the charging time is too long, the charger has no automatic power off function, and the battery is charged for a long time, which causes the battery to overheat.