Beauty instrument is a kind of machine that adjusts and improves the body and face according to the physiological function of the human body, it has whitening, skin rejuvenation, freckle removal, wrinkle removal, hair removal, weight loss and so on according to the function, according to the name, there are ultrasonic introduction, photorejuvenation, high-frequency electrotherapy, RF electric wave lift, electronic freckle mole, E light permanent hair removal and skin rejuvenation, etc., now small, micro beauty instrument has gradually become a trend, the power supply used in the beauty instrument has dry batteries, built-in batteries and AC charging, etc., At present, the mainstream beauty devices on the market are all beauty devices with built-in rechargeable batteries.

Electric shaver is the use of electricity to drive the blade, shaving beard and hair personal care appliances, electric shaver can be divided into rotary and reciprocating according to the motion characteristics of the internal blade, electric shaver power supply has a dry battery, built-in battery and AC charging, the current market mainstream electric shaver is the electric shaver with built-in rechargeable battery.

The hearing aid is a small amplifier that amplifies the sound that cannot be heard, and then uses the residual hearing of the hearing-impaired to send the sound to the auditory center of the brain, and the sound is perceived, which brings great convenience to the hearing-impaired. Hearing aids are mainly composed of five parts: microphone, amplifier, headphone, battery and volume control, so hearing aids need built-in batteries to meet daily use.