I'm trying to find without success a smart USB plug for the cigarette lighter to power my dash cam, but with a low voltage sensor to switch the device off of the voltage drops so preventing completely draining the battery. I'm running two Garmin mini cams, the rear is powered by a switchable obd2 port connector which has this built in, but the front cam is powered by the centre console power socket. I just know that sooner or later I'm going to forget to disconnect it, and flatten the battery. I've found an aussie shop selling one, but surely some e somewhere makes a simple integrated unit? 

this should do it Yosoo Health Gear Undervoltage Protection Cut Off Module, Battery Low Voltage Protection Board Module 12V Automatic Switch Recovery Protection Controller Module: AmazonSmile: Electronics & Photo

 

John