Adding a Shunt Help

[Almostblind]

We have a 2021 Rockwood Mini Lite 2205s. I added 2 6v batteries in place of the supplied 12v. The batteries are tongue mounted. It comes with a Go Power controller that I am not that impressed with. It was suggested that I should add a Vitron Shunt to more accurately monitor the batteries.
I have been Google searching for installation help, but everything out there is for batteries that are in compartments, not tongue mounted. Also, it seems that the shunts can not be mounted on the outside in the weather.
Does anyone know if there are shunts, or anything else that will more accurately monitor that can be used with tongue mounted batteries, or how to install a shunt with outside batteries?
Any help is greatly appreciated.

[MGD1961]

There probably is room to mount the shunt inside the battery box. They need to not get actively wet but not a sealed compartment necessarily

There are threads on others doing this.

[TacomaJoe]

Here's a kludge wire job for my old battery.


The shunt and battery were left over from my lithium upgrade. The basics are to jumper from the battery negative to the shunt, and then from the other side of the shunt to all negative connections. In the original installation I had a copper jumper from the post to the shunt but it didn't quite work for this one.

My shunt is wired so I have a cable to extend into the trailer but here it's just a wad of cable. In your 6V setup you will need to get the positive 12V sense wire over to the other battery.

[Aussieguy]

You can also get a weather proof junction box from hardware store

Run the negative battery cable to the shunt inside junction box
Then another cable from shunt to negative battery terminal

Solar controller negative goes to the shunt too

Solar controller only is a guide to what the solar puts into battery
I never look at mine for state of charge
Get the battery SOC from the shunt

[Almostblind]

Thank you for the info. I was thinking about doing something like that, but I was wondering if anyone else had done that and what success they had with it.

[reidfo]

I recently added a shunt along with solar controllers, and my batteries are on the tongue like yours.

We put the shunt and charge controllers in the passthrough compartment and pulled the original battery wires up through the floor into the compartment. Then we ran new cables from the shunt and bus bar in the compartment out to the batteries. Works great.

[Almostblind]

Thank you for the information. I'll see if this is an option that I feel comfortable handling myself or take it to a professional.

[tomkatb]

Kind of why?

Any device that reads the voltage of the battery will work with a little knowledge. Assuming a battery fridge odds of two nights is kind of slim. I would not need a monitor to know that.

Your next battery will likely be lithium. Many have built in battery monitors! They add just a few dollars to the price of the bms. All batteries should have them!

We had, the $30 Amazon battery monitor. More than adequate. We had 4-6 volt batteries. Installed in under 5 minutes.

[Almostblind]

Thank you for the info. I'll look it up on Amazon.

[reidfo]

Bear in mind, a battery monitor that only monitors voltage will work okay for lead acid or AGM batteries, but will not be accurate if you upgrade to Lithium. Lithium (LiFePO4) batteries have a pretty steady voltage until they're flat. A shunt will actually measure current going in and current leaving the batteries to tell you the state of charge.

[nvs4602]

Adding a shunt is pretty straight forward. The shunt connects to the negative battery post, then all other negative wires connect to the shunt.

The cheaper shunt meter on Amazon is the AiLi shunt Battery meter.

https://a.co/d/6LpyuFa

It's the one I use. Simple to use, you will need to calibrate it. This is done by fully charging batteries then running them until the bms shuts of,. Then fully charge again.

[mikehoyt]

I purchased the victron shunt for our new camper. Also added a simple 12v volt meter lkke we used to have in wolf pup. I will be mounting shunt in yhe pass through. Also should mention we also have 2 6v batteries.

I am about to do hhis on yhe coming weekend

Mike

[Capacitor]

Put the shunt on the opposite side from the two rectangular vents. During winter lay a sandwich bag over the shunt and be sure to drill drain holes in the bottom of the battery box. When you get lithium you can epoxy the vents closed.

[Almostblind]

That is helpful. Can you add a photo of your setup?

[SmittyCorp]

I made an enclosure out of an outdoor lawn sprinkler control box that I mounted next to the batteries. The shunt is in there, as well as a breaker for a small 250 watt inverter, and a fused power tap that I use for a water pump to fill my fresh tank from jugs. It'd be a lot less wiring if was the shunt only!

[Almostblind]

That is brilliant! I am going to try and copy what you did. It's hard to believe that with all the t.t.'s with front mount batteries, that there isn't a dedicated shunt box.
Thanks for the help

[SmittyCorp]

Glad I could help! I was lucky that the lid just barely clears the battery box, so I can still open if fully.

I made a backplane out of a cat litter bucket lid, this allows you to bolt the components in without drilling holes in the box. The box has standoffs to attach the backplane to.

It was a pretty fun project, and easy to customize!

[Aussieguy]

looks real good

you can lessen the number of wires to the shunt by using the frame as a busbar

then connect one wire to the shunt from frame

[Almostblind]

This is pretty much exactly what I want to do. If I can ask a favor of you. Would you be able to email me the photos? I can't enlarge them in the forum. My personal email is:
almostblind@netscape.net
Thanks again

[SmittyCorp]

On their way!