Hi folks,
Making a separate thread for the final install, but the journey started here:
https://tab-rv.vanillacommunity.com/discussion/17897/replacing-agm-with-lithium-in-2021-tab320-bd/p1Lot's of parts buying and returning in those threads! But here is what the end product looks like. I still need to clean up my front tub and connect a solar port up there for my suitcase. Thanks to everyone in the previous thread for helping, and particularly
@Yoshi_TAB and
@pthomas745 for answering questions as they came along.
The Battery:
I put in a LiTime 230ah battery and installed it in the rear passenger side by the AIR8 AC unit. This was an unused space for me, and the battery fits perfectly. As you can see, there is a little wiring harness down there - the angle makes this look closer than it actually is though. I had room to screw some brackets in on both sides for battery straps. I crisscrossed them, so the battery doesn't move in any direction.
I also installed the Victron Smart Shunt here to monitor battery levels. All the wiring used pre-existing holes, which you can see going out to the right here. There is still a little storage space to the left of the battery, but I'm not sure what I'd put here. Tools or spare parts that you don't need often would probably be a good choice.

Here we have the positive/negative passing through. Not much going on. I'll just include it if anyone is curious about where to run wires.

Here the positive/negative come into the WFCO compartment, which is next to the bathroom on the 320. I put a 30amp in-line fuse here, which you can see at the top. The negative goes straight into the grounding bar, which is hidden beneath that AC duct, but you can see a bunch of white wires going into it.
The Busbar and Switch:
This is where the biggest changes were made. I put the switch to the right of the CO2 detector, and a small LED right below it.
The busbar has lines to:
- The battery
- The new switch
- The MPPT solar controller (from VBATT+) - with 30 amp fuse
- A line to the front tub (connected to the old switch) - with 30 amp fuse
- To the junction box in the front of the trailer (black wire... I... ran out of my red wire)
The LED is connected to the line that goes out to the junction terminal and the grounding bar. This is a tip from
@yosh@Yoshi_TAB - the idea is if that light is out you should be concerned about power to your trailer brakes.

Here is what that looks like from the front:

And here is a shot with the seat down, because I think the switch looks very clean right there when the leg of the seat comes down.

I think that's it for now. I still need to clean up the wiring in the front tub, and I need to buy a new solar input port, because the one I have is installed in the side of the front tub, but I added additional tubs in the front. Once I clean that out, I'll have a ton more space, and I'm hoping my Honda EU2200i will fit in there... but it looks like that would be a tight fit... Excited to check out the new tongue weight too. Hope it isn't too light now!