While upgrading my campervan to a new power system (LiFePo + new charger), I also wanted to replace the existing ECTIVE battery monitor with something that can be consumed by the already existing VenusOS setup, which allows to remotely control and read out the system status through Victron’s VRM.

I discovered that the BMV-712 uses a standard CAT5 UTP cable during research. Researching further, it looked like the shut itself didn’t really carry a lot (or any) active components, which kind of surprised me but meant that it must be possible to use just five instead of 6 wires. The final breakthrough that gave me enough confidence to order the BMV-712 Smart that comes with a 500 A shunt was finding a post on the Segeln-Forum that contained the pinout, which showed that one of the wires was used for the “AUX” port (used for a secondary battery or temperature measurement). If you have just 5 cables available and need neither a secondary battery voltage nor battery temperature measurements, you can safely omit pin 2.

Pinout Shunt 500A / 50mV:

1 Voltage Body-Battery (Battery +12V)
2 Voltage Starter-Battery / Temperatur Body-Battery
3 Shunt - (Battery GND)
4 Shunt - (Load GND)
5 Shunt - (? GND)
6 Ub (+12V, BMV-712)

 

BMV-712/Shunt Pinout – view on the Socket: