Victron Energy BMV-702 Battery Monitor (Black), Retail

From the brand

Victron Energy BMV-702 features an additional input which can be programmed to measure battery temperature (temperature sensor sold separately) midpoint voltage, or voltage of a second battery, plus a relay that can be programmed to control other devices (such as a battery protect or generator)
Connectivity – use a VE.Direct Bluetooth Smart dongle (sold separate) to monitor on smartphones and tablets. Or, connect to a GX device via VE.Direct cable (sold separate) and monitor anywhere in the world with VRM
Displays % State of Charge, Voltage, Current, Energy/Time remaining, and more. Easy to Program for initial setup.
Incorrect installation can be hazardous, Please consult a licensed professional and follow all applicable electrical codes during installation