Victron Smart Shunt Midpoint or Individual Battery Monitoring?

manyman297

Getting ready to install the Victron Smart Shunt. Just a little stumped on if I should wire it to monitor midpoint connection to (2) 6v batteries or wire it to monitor both batteries individually. I have a 2021 400 BD.

williedean

Your 2021 400 BD has 2 6v batteries wired in series. Electrically this is the same as one 12 V battery. So as you follow the installation instructions, you will ignore the connection between the two batteries.  You will connect the red voltage monitoring cable from the shunt to the positive side of the first battery in series. The shunt will be installed in series between the negative of the second battery and the negative of the electrical system.  (Black cables in diagram).

Dutch061

With only 2 batteries I'm not sure there is much benefit to "mid-point monitoring". This is typically used on larger more expensive battery banks to allow a closer "look" at the health level of the individual batteries or individual groups of batteries. 

Mine is wired exactly as @williedean has posted above in our 2020 TAB 400 BDL. I did buy the temperature sensor input since I am installing 2 x Battleborn 100 AH batteries next week. Even though Battleborn has an excellent BMS (Battery Management System) that will prevent charging if the battery temperature is not high enough, I want to be able to monitor the effects of running the Alde in colder temperatures to see the effect it has on the temperature in the battery compartment. 

Brad

manyman297

williedean said:

Your 2021 400 BD has 2 6v batteries wired in series. Electrically this is the same as one 12 V battery. So as you follow the installation instructions, you will ignore the connection between the two batteries.  You will connect the red voltage monitoring cable from the shunt to the positive side of the first battery in series. The shunt will be installed in series between the negative of the second battery and the negative of the electrical system.  (Black cables in diagram).

Thanks guys! Saved me from doing more work than necessary.

manyman297

@williedean @Dutch061
Does it matter if I mount the shunt within the battery compartment? I'm noticing a lot of pics where the shunt is mounted outside of the battery box in the adjacent inverter compartment. 

Dutch061

You can mount it wherever it is most convenient to make the installation. On mine, it is under the bed with everything else (TAB 400 BDL) and I didn't install the gauge either. I use the Bluetooth application but have been thinking about running the wire and installing. It's just a pain in the butt to take the microwave out etc. to get it done.

Brad 

manyman297

Dutch061 said:

You can mount it wherever it is most convenient to make the installation. On mine, it is under the bed with everything else (TAB 400 BDL) and I didn't install the gauge either. I use the Bluetooth application but have been thinking about running the wire and installing. It's just a pain in the butt to take the microwave out etc. to get it done.

Brad 

Ok, great. I think mounting it within the battery box would be the easiest. At some point if/when we upgrade to lithium maybe it will get in the way? Maybe not. 

Yeah, I debated on getting the display but being really particular I'd want it by the other gauges at the entrance. My justification for not doing it is I always have my phone on me and the gauge only seems useful for at-a-glance checking of the battery charge. I know the included battery gauge on the 400 isn't accurate but it at least gives me some idea on where the charge is at. 

Dutch061

Yes, and chances are of you upgrade to Lithium that you will want to put them inside where they are much more difficult for someone to borrow without the intent to return. 

Brad

rrcbov

I installed the shunt in the battery compartment - seems to work fine.

manyman297

@rrcbov My installation pretty much looks just like yours. Everything turned out great. Wish the range was a little better but just glad to get it installed.

Dutch061

@rrcbov, looks great! I had previously installed mine on the floor ahead of the battery power distribution block because I didn't want to remove the panel to access the battery compartment. For once something I done previously worked to my benefit for a future upgrade. The Battleborn batteries leave no room in the battery compartment for anything but the batteries. 

Brad

YanniLazarus

Anyone actually use the midpoint monitoring for a pair of 6V batteries? Given the possibility of them becoming unbalanced it does seem like a good idea. I'm getting ready to install the newer waterproof model to monitor my 2 6V AGM's. I just don't see any Victron reference to 6V...

rh5555

When your AGM batteries fail, one will fail before the other.  Midpoint monitoring can give you a heads-up that one battery is dying before your whole system goes down, so this is a useful option.  You just need to set up a mid voltage alarm in the Connect app so that you are forewarned.

YanniLazarus

Thank you. That's what I want to do.  Have you actually done this with 2 6V batteries?  Victron doesn't mention 6V batteries in series in their multiple battery description. 

rh5555

I've done it, and it works with 2x6V batteries.

YanniLazarus

Thank you!