A on board charger is a device that can be used to charge electronic devices inside a car. Typically, the on board charger will connect to the car's cigarette lighter socket or USB port and provide power through the car's power system.

on board chargers are typically used to charge mobile devices such as cell phones, tablets, music players, etc. Some on board chargers can also charge multiple devices at the same time or support a fast charging feature to increase charging speed.

When choosing a on board charger, you need to pay attention to compatibility, power, and safety. Make sure the on board charger matches the connection port of the device, has high enough power to support the charging needs of the device, and has built-in overload and short circuit protection to ensure safe use.