Hi I have installed a BMV 12 into my camper trailer connected to a 120Ah AGM battery. I have followed the instructions. With no load on the system, the app is reporting -1.1A current and -16W power. Why would the monitor be using that much power?
asked
BMV 712 power useage
Unless your BMV came with a free mini-heater its not drawing 16W of power!
The BMV-712 particularly, has a very low current draw - less than 1mA with the back-light off (<0.001A). It basically runs on air... :-)
The first thing I would do is to temporarily disconnect any cables connected to the 'load/charger' side of the shunt and see if the reading returns to 0.00A. If it does then there is something else in your system that is drawing this current and you will need to investigate further.
If there is no change to the BMV current reading and you are sure that it is wired correctly (ONLY the battery negative cable connected to the 'battery' side of the shunt and nothing connected to the shunt PCB screws), then you can perform a 'Zero current calibration'.
You will find the 'Zero current calibration' button in the VictronConnect app under Settings > Battery. Just be sure to temporarily disconnect any cables connected to the 'load/charger' side of the shunt when you do this (to ensure that there is really no current draw physically possible).
Finally it may also be possible (but unlikely) that there is a fault, like a bad connection with the UTP cable between the shunt PCB and display, the shunt PCB could be loose or something else internal.
Thanks @Mark. Looks like the zero current calibration did the trick.
Before posting the question I had already removed any possible load and it was still saying 1.1 which I thought that is ridiculously high. So it was just a calibration thing. I wonder why it was so out of wack?
Really not sure sorry, the normally read 0.00A out of the box with nothing connected, but it is not totally uncommon (hence the button).
Just make sure the PCB to shunt screws are secure and that the reading doesn't change if you move/jiggle the UTP cable ends from side to side. If that's all OK, I think you will be right going forwards.
