Now you don’t need any installation to protect your battery. This inline device connects with a cigarette lighter plug and socket, and automatically shuts off power to the connected device (such as a fridge or lighting) if the voltage drops below 11.6V! Power is automatically restored when voltage exceeds 12.8V (eg, the vehicle engine is started). It’s simple peace of mind when running power-hungry equipment at a campsite, for instance. Suitable for loads up to 10A.