Victron - BMV-712 Not working as expected?

[J&J___]

Battleborn called me back & they had me change only one of the settings you told me- so you were definitely on the right direction - they told me to change "charged voltage to 14.2". They also told us to reverse the lines to the shunt (bus bar) in the battery box, then when it got fully charged hit Synchronize. Current readings. Oh, I don't have a thermostat on this I am guessing, because it is much warmer than 30º

Attachment 26183

Thanks for the info. 14.2 does make sense.

Why did they think your shunt was in backwards? From your pictures I can’t trace your connections. The shunt terminals are labeled “To load” and “ To battery”, trace your cables to see if it is hooked up correctly. If not hooked up correctly you probably want to remove the shunt and turn it 180 degrees and put it back in instead of trying to redo the wires. Depending on how the wires were done it may be difficult to reroute the wires.

If you look at page 12 of the manual, “charge and discharge currents are inverted” it says the cables on the shunt are bakwards if you get positive values on discharge and negative values on charge. I just did a test on my setup and when I turn off my converter and put a dc load on the batteries the app shows negative current and negative power values. When I turn my converter back on the app shows positive current and positive power until the battery is charged.

You can manually sync the system when the battery is full but it looks like it does an automatic sync when the battery gets fully charged after a discharge. You might want to do a longer test. Turn off your converter and put a DC load on the system. Turn on all lights and fans. As long as you turn the breaker for your converter off you can leave the ac and fridge on since turning converter off forces all DC to be pulled from the batteries. I think you said you have a small solar charger on the system. If there is an off switch turn it off or pull the fuse to keep it from influencing your readings. The battery monitor only reads what is going into or out of the battery at a given point in time.

[zadiemay]

Our shunt doesn't have "Load or Line" on it - one side says 500A & other is 50mA. So the way it was hooked up was 50mA was coming from the trailer (so load?) and the 500A was the batteries. Battleborn said it needed to be the other way... So now the Load is on the 500A stud. Is is normal the the batteries go down even while being charged? We are plugged in & the batteries this morning - see pic. Not sure why it keeps losing %, but then if we go unplug the SP, it will go back up to 100 usually right away.... Does this look correct?

[Redapple63]

Sounds to me while you are plugged in you are not getting any charge, so it is displaying usage. It will still show negative even when charging if you are drawing more than is being returned via charge.

Example, maybe running the heater and fridge, solar pumping in 20 amps, but you are using 25, will show -5 amps.

[zadiemay]

Sounds to me while you are plugged in you are not getting any charge, so it is displaying usage. It will still show negative even when charging if you are drawing more than is being returned via charge.

Example, maybe running the heater and fridge, solar pumping in 20 amps, but you are using 25, will show -5 amps.

We have a little solar on the battery box, like 10a, but other than that, we only have the things you can't turn off on 12V... Why won't it charge while we are plugged in? Yet the voltage says 14.45 right now, but 89%. I thought 14.45 was a full charge.

[J&J___]

Our shunt doesn't have "Load or Line" on it - one side says 500A & other is 50mA. So the way it was hooked up was 50mA was coming from the trailer (so load?) and the 500A was the batteries. Battleborn said it needed to be the other way... So now the Load is on the 500A stud. Is is normal the the batteries go down even while being charged? We are plugged in & the batteries this morning - see pic. Not sure why it keeps losing %, but then if we go unplug the SP, it will go back up to 100 usually right away.... Does this look correct?

I am also new to this but here are a couple of observations. The way your shunt is mounted the labels for “to load” and “to battery” are on the bottom of the shunt with the power and temp connectors so you will need to take the shunt out to see them. On my shunt the 50mv side goes to the battery and the 500 amp goes to the trailer loads, so it appears that your shunt is/was hooked up backwards. It sounds like you changed the connections and are still getting strange readings. You might want to disconnect the power to the shunt then reconnect it forcing a restart of the shunt electronics. It is electronics and you never know, a cold boot might fix it.

Something else I see in your photos is that you have multiple negative connectors on both of your negative battery posts. There should be one wire that goes from battery 1 negative to battery 2 negative to connect the batteries together and one wire that goes to the shunt. Trailer and all other loads need to be on the other side of the shunt from the battery. On my system I have a wire that goes from the batteries to the shunt then a wire that goes from the shunt to a busbar where the trailer negative, solar charger negative and the inverter negative connect.

[J&J___]

Note:
Page 11 of BMV-712 manual says that if power to BMV is interrupted the battery monitor needs to be resynchronized before it will operate correctly. In my previous post I suggested maybe try a power interrupt to reset the shunt. If you do it looks like you need to do a manual resync.

[DriverDon]

Something else I see in your photos is that you have multiple negative connectors on both of your negative battery posts. There should be one wire that goes from battery 1 negative to battery 2 negative to connect the batteries together and one wire that goes to the shunt. Trailer and all other loads need to be on the other side of the shunt from the battery. On my system I have a wire that goes from the batteries to the shunt then a wire that goes from the shunt to a busbar where the trailer negative, solar charger negative and the inverter negative connect.

I agree with J&J___, you should only have one cable connecting the 2 negative battery terminals, and one cable from 1 negative battery terminal going to the shunt. Not sure what that other small wire is, maybe your mini-charger?