Victron smart shunt install help

Yoshi_TAB · July 2021

Hi,

Looking for some advice to help me get a Victron smart shunt installed in a 2021 TAB 320. I have two 12V batteries in parallel. See attached for wire diagram. There are 3 wires to the negative terminal on battery #1, one from the battery switch, one from the jumper to battery #2 and one from that goes into the TAB somewhere (I'm guessing the solar panel). Battery #2 has two wires on the negative terminal, one from the jumper to battery #1 and one from the external solar panel plug.

I believe the shunt gets connected directly to the negative of battery #1, but I'm not sure if all 3 (or just the one from the switch) negative wires get connected to the other side of the shunt? Does anything happen to the negative wires on battery #2?

Also, do both positives wires for the shunt get attached or just the one to battery #1

Thank you

Image: https://us.v-cdn.net/5021717/uploads/editor/gz/26zgk6k3h6yb.jpg

Denny16 · July 2021

Your batteries are not wired correctly. You should have all the negative loads on one battery and all the positive loads on the other battery, so current load is flowing through both batteries. The way you have it wired with only solar charging to one battery and the loads connected are only connected to the other battery (#1). While this works, you are using battery #2 to charge battery #1, not an ideal setup, but it is OK.

The battery monitor shunt needs to go between the negative terminal of the battery and all negative load connections. The battery switch only switches the positive side of the battery loads, not sure why you have a negative wire going to the switch. In any case, you remove all the negative wires from battery #1 in your drawing and connect them to the load side of the shunt. The other (battery) side of the shunt goes to the battery. The solar panel negative connections also should be connected to the shunt.

You will need to connect all the negative load and solar connections to a bus bar which has multiple connections tied together, with one wire going from the shunt load connection to battery #2 negative post. All the positive connections can stay on battery #1. This way the total battery load and solar charging will flow through both batteries equally. Leave your two battery jumper connections as you have them. So battery #2 will have the shunt and negative jumper cable on it.

Note: Be Safe There is a huge amount of energy stored in these batteries, if you short one out it will go BANG… if you connect two together the wrong way… it still goes BANG but a lot LOUDER! Seriously, if you have any doubts, get an Auto Electrician to do it. Getting it wrong will seriously hurt you.
cheers

Yoshi_TAB · July 2021

I understand, that makes sense. Let me double check my connections to make sure I provided the correct info. This is how they were wired when I received the camper. , Thank you

Yoshi_TAB · July 2021

Hi, I confirmed my sketch is correct.

Re: Negative wire to switch; I don't know how the switch is wired. Is it possible the switch is just acting as a pass through to the ground for the camper?

Can the positive wire going to battery 2 from the switch be acting as a positive jumper between the two batteries (isn't that how batteries in parallel are wired)?

You said leave the two jumpers on, but I only see one for the negative. what is the other you speak of?

If the above is true, it would be wired correctly (I think).

Not sure why the plug for the add on solar panel is wired to battery 2

Thank you,

ColoradoJon · July 2021

Here is a diagram that may help. All negative loads and chargers get connected to the shunt load side. The red positive lead to the shunt is to provide power to the monitoring device.

Image: https://us.v-cdn.net/5021717/uploads/editor/kr/56fhgmhwroqd.jpg

Yoshi_TAB · July 2021

Hi, Thank you, very helpful to compare....mine is close but slightly different

Differences:

1. My positive and negative wires from the external solar port goes to what you show as your lower battery.

2. I have a second positive from the shut off switch to what you show as your lower battery. Can this be acting as the positive jumper you show to the lower battery? I'm thinking so as this wire is not "paired" with any negative wire. I can't see behind the switch, but if the positive goes to the same lug on the switch, it would be acting the same as your diagram.

So for me to use the shunt. I remove the 3 negatives from the external solar port, switch, & solar controller and attach load side of the shunt. The other side of the shunt gets attached to the my second battery or what you show as your lower battery.

The only difference will then be (1) External solar port positive is going to what you show as the lower battery. (2) The positive "jumper" is different.

ColoradoJon · July 2021

1 - Your positive and negatives for the external solar port should go to the same terminal as all of your other loads and chargers. If the jumpers between batteries are short (12-18") and heavy gauge, it really is not imperative.

2 - If I understand this correctly you have a dual battery shut off switch. The positive terminals from both batteries connect to the switch and is intended to switch between the two batteries, not parallel them together. The intention is to allow you to use one battery, then switch to the other when the first one is drained. I would jumper the batteries and then connect only to one side of the switch, or replace the switch altogether.

3 - Correct!

Yoshi_TAB · July 2021

Hi

Re: #2; It is not a dual battery switch. I've attached a photo from the trailer and a catalog cut from the rear of the switch.

There are two positive wires coming from the switch. One to each battery. I'm not sure if the second wire from the switch serves as the "positive jumper" between the two batteries. The second positive wire does not have a "paired" negative wire with it, just a stand alone single positive wire. So, I'm thinking it serves the same function as a jumper...but not my expertise.

Thank you,

Image: https://us.v-cdn.net/5021717/uploads/editor/79/dbeuny0kke1s.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/mu/us07yyrsm42g.jpg

ColoradoJon · July 2021

Ahh, I see, I misunderstood. With that switch the battery positive is connected to one side and then your RV positive connects to the other. You should not be connecting both batteries to the switch. If you have two positive wires coming from the switch, one to each battery, they are connected to the same terminal on the switch. This is effectively creating the positive jumper between the batteries like you said. It's not recommended but it does work and won't cause any problems.

Battery negative connects to the shunt and then your RV negative connects to the load side of the shunt.

Yoshi_TAB · July 2021

Then I'm good. Thank you for the help.

Update: All hooked up and working.

Victron smart shunt install help

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