How Should I Wire My Batteries in Parallel While Using the Victron SmartShunt Battery Monitor?

Updated 04/27/2026 | Published 04/22/2026

Question:

I just bought the Victron SmartShunt Battery Monitor - 300 Amp Part Number: VN25VR and I have 2 100ah lithium batteries wired in parallel for my travel trailer and was just curious if there was a diagram or something to help me make sure I wire it correctly. Thank you!

asked by: Larry R

Expert Reply:

Hello again Larry,

Great question, I am sure there will be a lot of people wondering the same thing.

I attached a diagram to help show how to wire up your (2) 100Ah lithium batteries in parallel with the Victron SmartShunt Battery Monitor - 300 Amp # VN25VR.

The main thing to keep in mind is that all of your negative current needs to run through the shunt so it can read everything correctly. This is what keeps your readings accurate and also helps avoid wiring issues.

Your positives are pretty simple. Both battery positives get tied together and then run out to your system through your main fuse. Nothing on the positive side goes through the shunt.

On the negative side, both batteries tie together just like the positives, but instead of going straight to ground, they go to the battery side of the SmartShunt. Then from the other side of the shunt, you run a single cable out to your trailer’s ground or system negative. That way the shunt can measure all the current going in and out.

You will also have the small fused positive wire going to the shunt. That just powers the unit and lets it read voltage. The temperature sensor cable plugs into the shunt and attaches to one of the batteries.

One other thing you will notice in the diagram is the balanced wiring. Your main positive and main negative are taken from opposite batteries. That helps keep both batteries charging and discharging evenly.

Before you power everything up, I would just double check a few things: make sure all system grounds are on the load side of the shunt, confirm your connections are tight and clean, and verify your fuse is installed on the positive lead.

If you follow the diagram you will be set up correctly with your # VN25VR.

What kind of rig is this going in? Are you more of an off grid camper, or do you prefer staying at maintained campgrounds?

expert reply by: Kate F

Wiring Diagram for Parallel Batteries Using Victron SmartShunt Battery Monitor
(click to enlarge)

Dave

4/23/2026

Yes this diagram is correct,,I have two 100 amp lithium hooked in series to make 24 volt for my trolling motor on boat,,series is different than parallel,,also lots of good info on you tube,,,this Victron Amp is awesome,,,good luck

Kate F.

4/27/2026

@Dave Hey Dave, thanks for the response. Not sure if you have heard of these yet, I put a set on my my batteries to bump my Garmin to 24 volts, it is not a needed part, but they are pretty sweet: Connect-Ease Standard Series 24V Trolling Motor Wiring Kit # CE58RR

Dave B.

4/27/2026

Hi Katie,I have seen those adapters,they are great,I haven’t a few boater friends that have them,,love them,,,thanks Dave

Kate F.

4/27/2026

@DaveB Thanks for the feedback on them. We just brought them on our site months back, I was pretty excited about them!