Wiring questions for 2019 T@B 400

Jilong

I took a look at the wiring inside my T@B 400 by the battery box. I couldn't figure out how to open up the large black battery cover so I'll save that for another day, but there were two terminals protruding from the side of the battery box where there different devices were directly connected.

1. AIMS 1200W inverter
2. SR HP-2440B solar charge controller
3. Battery disconnect switch

I was surprised to see that the inverter was wired to continue to function even if the battery disconnect switch was set to OFF. Is that normal?

I'm planning to install a Victron BMV-712 battery monitor that I recently purchased, and I thought it would be relatively straightforward to wire in the shunt, but after looking at the existing wiring, I'm not so sure where everything should go.

1. I'm planning on putting the shunt in front of the inverter and the solar charge controller, but I'm not sure about the switch. Which should be "closer" to the battery, the shunt or the switch? If the switch should be closer, do I need to worry about voltage drop across the switch? I think it would be about 4 feet of wires plus the switch.

2. I'm planning to put the inverter behind the switch so when I set the switch to OFF the inverter also loses power. Is that sensible?

3. Should the solar charge controller also be behind the switch, or is that a bad idea because then the energy produced by the panels has nowhere to go when the switch is OFF?

jkjenn

1.  I put the battery switch from the positive and shunt to the negative. They are equidistant.

2. That is what I would do.

3. Since you want to wire the SCC to the load/charge side of the shunt, I would wire the SCC to the load side of the battery switch, or better yet, use a bus bar.

Ignore the error stuff...that was the SCC, not the wiring, but here is how I fired mine. 

https://youtu.be/9aomoio9YJ8

Jilong

@jkjenn Thank you, that video was very informative. It makes sense to take the switch out of the equation by moving it to the other side of the circuit.

Is it worth using bus bars, or for these few devices I can just attach the rings to the battery terminals? I guess from a long-term maintenance standpoint, bus bars are better because it's simpler to disconnect and replace the battery, as well as easier to add any additional devices in the future and have them automatically be in the correct place in the circuit relative to the shunt.

Okay, okay, you've convinced me! Now to figure out where to put everything. I may reuse your Tupperware idea in order to protect the shunt, bus bars, and wires. In the T@B 400, the battery box is basically in the under-bed storage area and it's a pretty high-traffic area since it can be accessed from the outside as well, so something to protect the wiring is a must.

k4man

@Jilong, just read thru your post, as I'm considering the BMV-712. I was wondering if you ever got your BMV-712 all hooked up? We have a similar 2020 T@b 400 set-up with solar, inverter, 2 batteries, etc. I'm wondering if you would mind sharing a photo or photos of how you eventually set yours up with the BMV-712?

TNOutback

If your battery switch is in front of the SCC, (and turned off) then you won’t be able to charge your battery while having all the drains isolated from it.  I would think you would want your solar to be charging the battery whether isolated from loads in the camper or connected.

gspdx

The cables going to my inverter are much bigger than the cable that goes to the battery shut off switch.  It I wanted a switch to disconnect it from the batteries I would add a new switch and appropriate size cable.  

I also just added the bmv-712.  Took the negative cable coming out of the battery box off the 2pole bus bar.  Hooked that cable to the shunt on the side marked battery.  With a 16"  #4 cable I hooked the load side back to the bus bar where the negative side battery cable was.
 

gspdx

Not the best photo but it might help.