Ultimate Toys CS-S LiFePo4 Upgrade

rfuss928

When we took delivery of our UT, I installed dual 100ah AGM batteries in the front tub leftover from SUNT@B.  Kind of a quick install using salvaged wiring and the existing connections in the front tub of the new UT.  This coming season would be the fifth for these batteries and although they still test close to new capacities, the previous pair let me down when they were this old.  I rationalized it was time for the lithium battery upgrade.
Initially I hoped I could just drop a pair of Li batteries in the same place and work with that set up.  Reality soon struck.  First thing was the WFCO 8735AD did not recognize the Li batteries.  During discussions with the WFCO tech it became evident that the long 10awg wiring to and from the front tub was part of the issue.  I had to pull the converter out to return to WFCO for a warranty firmware update. (see:  https://tab-rv.vanillacommunity.com/discussion/16210/wfco-wf-8735-ad-lifepo4-fyi-on-annoying-auto-detect-quirk#latest )  It became obvious that there was an ideal interior location for the batteries in the rear bench right next to the converter and much closer to the solar controllers.  Wiring could be substantially shorter for the converter and all the chargers plus the space could be reclaimed in the front tub.  The Li batteries were ~25 pounds each instead of the ~75 pound AGMs which made moving them into position anywhere much easier.  It also became evident that the TV would no longer be able to charge the batteries without a DC-DC converter/charger so that was also added.
Other than crawling underneath for rewiring the +12v from the 7 pin cable to an abandoned solar charge wire from the front tub, all the work was done inside the trailer.  The battery selector switch, Smart Shunt, and circuit breaker are mounted to a plywood panel held in position by the battery hold down strap.
Everything is up and running as expected.
Here's a few photos of where it all fit...

 

Sharon_is_SAM

Will it be inconvenient to have the battery cut off well under the bed?

rfuss928

Sharon_is_SAM said:

Will it be inconvenient to have the battery cut off well under the bed?

The switch was under the closet floor in SUNT@B and I never found it to be a problem.  I really only use it during service or winterizing and can crawl under the mattress to access it other times if needed.