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.

californication

@rfuss928 couple questions about your setup.

1. Do you have any schematics of wiring to the internal piece of your system? How did you know which wires are going where? Like 110V system or solar systems? Trials and errors?

2. You mentioned you rewired +12V from the 7pin cable to abandoned solar wire. Does it mean you repurposed wires from the front tub?
3. Follow-up to the 2. Is there a direct access to +12V from the TV cable? Or did you have to splice it and extract it?

Thanks.

rfuss928

californication said:

@rfuss928 couple questions about your setup.

1. Do you have any schematics of wiring to the internal piece of your system? How did you know which wires are going where? Like 110V system or solar systems? Trials and errors?

2. You mentioned you rewired +12V from the 7pin cable to abandoned solar wire. Does it mean you repurposed wires from the front tub?
3. Follow-up to the 2. Is there a direct access to +12V from the TV cable? Or did you have to splice it and extract it?

Thanks.

1. No schematic.  I've been working with electrical systems my entire life.  I don't have much trouble tracing wiring or building simple systems,. No trial and error...
2&3. Yes, I repurposed one of the solar charge wires that originally ran to the front tub because it is no longer used and it already ran to the location I needed.  The solar controller is in the interior near the batteries and converter so the wiring could be much more direct now.  The 7-pin cable goes to a junction box underneath the front and I removed the +12v wire from the terminal block and connected it to the spare solar wire running to the same area I located the DC to DC converter.  

californication

@rfuss928 thanks!

I'm interested in moving LiFePo4 to the inside. Additionally, I'm checking Victron DC/DC Isolated and I'm hoping to either add another solar panel on top of the tab or an external plug for external/movable panels.

I'll give it a try in next few days, so I might have more questions!

Thank you for your description, I'm gonna have an easier start

SLJ

californication said:

@rfuss928 thanks!

I'm interested in moving LiFePo4 to the inside. Additionally, I'm checking Victron DC/DC Isolated and I'm hoping to either add another solar panel on top of the tab or an external plug for external/movable panels.

I moved and installed Lithiums under the passenger bench in my '21 320S when I got it. Wasn't enough room for two on the other side. I went for an external suitcase as we park in the shade whenever possible.

Sharon_is_SAM

@SLJ - we are considering installing lithium and we use portable solar.  How do you hook up your controller and panels?

rfuss928

Sharon_is_SAM said:

@SLJ - we are considering installing lithium and we use portable solar.  How do you hook up your controller and panels?

I have an SAE outlet in the front tub.  I use a 120 watt portable panel to supplement the roof panels if needed.  I use a Victron Smart Solar controller for the portable just before the "outlet".  I also use that connection to power a portable compressor cooler when overnighting or off grid. 
I placed a terminal block in the tub for the original battery wires,  A handy 8 awg connection to the batteries now inside by simply repurposing the original factory battery wiring. This outlet is connected to that terminal block.

SLJ

Sharon_is_SAM said:

@SLJ - we are considering installing lithium and we use portable solar.  How do you hook up your controller and panels?

I moved the Renogy controller that was mounted in the 200 watt suitcase to inside the tub behind the SAE connector on the tub. Don't get as much power loss when using a 20' cable on the 

suitcase sitting out in the sun when the controller is closer to the batteries.

Sharon_is_SAM

@SLJ  - thanks!

@rfuss928 - So, portable panels connect to a third Victron controller (I guess mounted in the tub), that connects to the Anderson, that connects to the terminal block, that connects to the original 12v wiring.  What is the gauge of the original wiring?  Not sure where the 8 AWG comes in to play.  

rfuss928

Sharon_is_SAM said:

@rfuss928 - So, portable panels connect to a third Victron controller (I guess mounted in the tub), that connects to the Anderson, that connects to the terminal block, that connects to the original 12v wiring.  What is the gauge of the original wiring?  Not sure where the 8 AWG comes in to play.  

The third Victron controller has short SAE pigtails on the input and output.  I just set it in the tub, plug the output in the connector shown and connect the panel wiring to the input,
The original battery wiring from the tub to the converter is 8 awg.  I terminated the battery connections at a terminal block located on the back wall of the tub. The other end remains connected to the battery wiring at the converter.  The SAE connector is wired to the terminal block.  

Sharon_is_SAM

Thanks @rfuss928!

Sharon_is_SAM

@rfuss928 - does the Ultimate Toys CSS have the WFCO 8955 AD?

rfuss928

Sharon_is_SAM said:

@rfuss928 - does the Ultimate Toys CSS have the WFCO 8955 AD?

WFCO 8735 AD.  (see link in OP about firmware update)