Hello, I have an 12v 3 bank charger and a two 12v battery bank in serial for my 24v trolling motor. I want to install an BMV 712 Smart to monitor the 24v bank.
The problem I have with this setup is the 3 bank charger that connect to each battery.
Thanks for helping me
These are the connections, but follow the sequence in the manual.
Connect the battery side of the shunt to the negative terminal of the left battery in your diagram.
Connect the existing charger negative to the load side of the shunt.
Connect the Existing negative to the load side of the shunt.
Connect the thin red wire to the positive of the center battery and the left (check manual if unclear) green connector.
Connect other red wire to one end of the bridge between the left/center battery and the right green connector.
Plug in the remaining cable with RJ plugs.
Configure etc.as per manual with Victron connect for battery capacity and mid point monitoring.
thank you very much but your diagram works with a 24v charger but this is not my case. I dread having a conflict with my 3 bank charger.
Alexandra is/was using it to demonstrate wiring for the extra battery only. But looks as if she deleted to remove the confusion.
Did my verbal instructions help?
Hi fisherm - did you ever get this resolved? I've run into the exact same issue. You'd think it was not all that unique, but I can't find an answer to this ANYWHERE! I think I want to just try feeding a negative to my 2nd battery from the P-, but I'm worried about causing damage to something. BatteryDiagram.jpg
I have the same challenge as FisherM. I can't figure out how to connect a BVM-712 when my batterys are connected in Series and I have a Multi Bank Charger. I've searcehd the Forums and Internet and cannot find an answer.
Here is my system:
I thought installing the BMV-712 Smart Shunt would be easy (see next picture). But these seems wrong after reading the BMV-712 Manual. The manual says the charger should be installed after the the shunt?
So how should I do this? The next diagram is the best I could come up with, but it doesn't feel right. The Minn-Kota Precision Charger manual and my manual for the LifePo4 battery's suggest that each battery needs to be directly connected to the charger and I should not make a common ground. I'm confused. Any help would be appreciated. This feels like the exact same challenge that fisherm and Carybo are having (just more batteries in series).
Danger your second diagram will set fire to all of your chargers negative leads.!!
With this diagram you can only see the correct Soc of the first battery.
If you fully charge all 4 batteries, that might be good enough. Given that the motor will equally discharge all 4 batteries.
You can monitor the overall 4S battery voltage, as well as the mid pack voltage deviation with the BMV.
Probably not recommended, but see what others think.
Your idea and updated diagram is better than anything else I've found.
The problem I see there is that the BMV will see the discharge from all 4 batteries and the charge from only one. There's no real fix for this apart from using a 48V charger. A workaround might be to manually set your BMV to 100% when you know it's fully charged, then just run with the discharge readings.
