Seeking some information regarding the USB Charger for the Viofo A119S in supplying 3.1 amps. There are two USB ports on the charger, one most likely low voltage and the other high. My question is, is the 3.1 amps per usb port or in total? I would like to use an additional 119S for rear window using the same charger. Would there be enough voltage to power both cameras without any issues? Any and all responses are truly appreciated.