The face washer has a polymer lithium battery (similar to a normal Bluetooth small speaker) inside, so that after the battery is fully charged, it can provide a few hours of use time for the face washer.
Inside the face washer is the battery connection switch, the switch is disconnected, the battery is completely disconnected, not used for a long time, the instrument will not leak, that is, the battery self-discharge, the internal lithium battery will still store enough power (normal lithium battery is placed for three months, the power will still have more than 70% of the remaining power), and can be used.