Tag: Can I directly charge the battery with city electricity? Answer: It is absolutely not possible. The mains electricity is alternating current, its voltage is 220V, and the charging voltage of the battery is about 14.5V. If you charge the battery directly from the mains, the consequences are really disastrous. Therefore, we must use a regular charger to charge the battery. Moreover, the appropriate charging current should be selected according to the capacity of the battery, so as to ensure that the battery reaches its maximum life.