Wiring New Lithium Batteries into the Pass Through Storage Area.

[joe53559]

Hi All. I'm installing solar/lithium into my 2014 Reflection 293RES fifth wheel. As I replace the old batteries with the lithium I'm moving them from the front compartment (where they could be vented) to the environmentally controlled pass through storage area to keep them cool. This leaves behind two small BUS in the front compartment (one pos, one neg) that appear to be direct-wired to the old batteries, meaning they draw power from the battery bank without going through the fuse panel first. The BUS also have some items also wired to them, such as the front jack motor. My question is does anyone know the wiring diagram well enough to tell me if (once I've moved all the batteries to the pass through) I need to run a six gauge wire back up to those BUS's from the batteries to power those items, or will the 12 V fuse panel array take care of that for me?

[gbkims]

Hi All. I'm installing solar/lithium into my 2014 Reflection 293RES fifth wheel. As I replace the old batteries with the lithium I'm moving them from the front compartment (where they could be vented) to the environmentally controlled pass through storage area to keep them cool. This leaves behind two small BUS in the front compartment (one pos, one neg) that appear to be direct-wired to the old batteries, meaning they draw power from the battery bank without going through the fuse panel first. The BUS also have some items also wired to them, such as the front jack motor. My question is does anyone know the wiring diagram well enough to tell me if (once I've moved all the batteries to the pass through) I need to run a six gauge wire back up to those BUS's from the batteries to power those items, or will the 12 V fuse panel array take care of that for me?

The black wire that runs from the disconnect switch usually lands on a circuit breaker in the front compartment & another black wire runs off the same circuit breaker back to the fuse panel.
Probably could leave that wire on the fuse panel and feed the front circuit breakers that remain in the front compartment.

Mine just had 2 CBs and one had the 2 black wires on it from the disconnect switch.

FW 317RST OEM Wiring 2020-07-27pdf.pdf

[RickLight]

Since even identical model/year trailers have different wiring I suggest you trace out yours.

I did the same mod. I rerouted all the wires that go to the distro panel. The one that goes through the underbelly to the front I hooked directly into the batteries. Then reversed the 50A breaker up front and fed all the other front loads. Remember your breaks need un-switched power in case of breakaway.

[TucsonJim]

Just for clarification. I read that you're moving the batteries from the front storage to the pass through storage in order to keep them cool. The pass through storage area has ducts for heating when the furnace is running, but there are no ducts for air conditioning. On a very hot day, I'd be curious it there are significant temperature differences between the pass through and the front storage?

Jim

[RickLight]

My batteries usage temp range is -4 to 130F. Charging a bit tighter, especially lower end.
While there isn't an AC duct, there is significant venting to the living space.

[Guest]

This is an interesting topic where I just returned from an 8 day dry camping trip where I had been monitoring battery temperatures when charging.
When wiring in my Lithium battery, the thought was to move my battery from the trailer tongue of the Imagine to the passthrough to provide protection from direct sunlight and high moisture conditions. My passthrough may be similar to Ricks storage area since my passthrough does not have heating or cooling but would have some radiant benefit from the living space which would be heated or cooled in most cases. Except dry camping when no heating or cooling is used.
My passthrough temperatures lag behind the outside ambient temperatures and was cool on the late mornings when I was charging. Temperatures of the battery have been around 35F higher than the passthrough temperatures by the time the battery reached an 80% SOC. If I had charged during the day when the passthrough temps were around 80F my battery temp would have exceeded 115F which is at the higher end of the specification. The concern is that cells at the center of the battery pack may be running hotter that what I had been measuring from the positive battery post, even though no BMS shutdowns were encountered.

So I'm planning on ventilating my marine style battery box and will re-test. If the battery does not run cooler, the plan is to make up a battery box with a thermostatically controlled fan. This way, cooler battery temperatures under hot conditions should help to achieve maximum battery longevity.

Jim