There is a small hole back of the controller( hidden a reset button in the hole) use a needle press it. Charging port: Type C, Charging 3hours can use 7-8 hours.Built in 300mAh lithium battery. Don’t use quickly charger, high power charger and the Switch original charger.High-power chargers can easily damage the controller.
https://www.amazon.com/IINE-Cartoon-Wireless-Controller-Nintendo/dp/B083DNW3P9