Just so I'm getting this Correct the "L" pin Supplies a 3.3v Live, When the "H" pin Receives a voltage of 3v or higher it turns the device on, and less the 3V it turns the device off? If this is the case could I Ignore the "L" pin on the devices and Wire a 12V live from the Battery into the COM port of the Relay and then just Parallel the "H" pins from the NC relay port. when the Relay in the BMW is normally closed the charger & MPPT would be ON, when the low temperature triggers ( or any other trigger ) , it will open the relay which would turn off the Charger and MPPT ( and prevent my lithium battery is charging when cold and my Batteries internal BMS doesn't have low temperature charge cut off )