2023-02-28 00:00:00 GSPBATTERY SMART SLIM PRO black box auxiliary battery is the state of the car's main battery voltage, the voltage of the auxiliary battery, Built-in battery information display function such as current and remaining charge capacity. The auxiliary battery for the black box developed by GSPBATTERY is an app that allows the vehicle owner to know the battery status at any time by monitoring and manipulating various data and status of battery usage through Bluetooth.