Lithium or AGM Battery Mounted Inside a 320 Cabin?

Bayliss · November 2021

Thanks @jkjenn. I will check out your video.

tomtek · November 2021

I upgraded to 280aH DIY Grade B Lithium Cells I assembled along with relocated battery in the cabin passenger side wheel well storage of 2021 CS-S. I upgraded the converter to a PD4060(LI) and have upgraded wiring to handle the higher charge currents. Other notes is the addition of a 1200 watt inverter and automatic cut over switch for inverter. Its been a major electrical overhaul but am extremely pleased with the result and it's possible I may add another 280aH of Lithium. I watched @jkjenn video before my work and got a lot of great info from it and was able to make a more informed choice of my conversion. Thanks @jkjenn great video with precise reasoning behind your decisions. I have a few other electrical changes I am happy to share if there is a request.

CrabTab · November 2021

tomtek said:

I have a few other electrical changes I am happy to share if there is a request.

Sharing is caring @tomtek

Start a new discussion, so we don't have to wade through all of this one to see your ideas. I find it hard to later look back at concepts when they're hidden within a discussion of a different title.

Bayliss · February 2022

Thanks to the input and assistance from several forum members, in conjunction with upgrading to the Isotherm two-way refrigerator (documented in a separate discussion thread) I successfully completed the installation of a Battle Born 100Ah LiFePo4 lithium battery inside the driver's side electrical compartment of my 2019 T@B 320 S Boondock. The installation was fairly straightforward and included adding the Victron BMV-712 battery monitor and a Furrion Solar Port for use with my Renogy 100W Solar Suitcase.

Battery Installation: I added some "Fastronix" flexible battery post covers (for the battery) and 3/8" stud flexible boot covers (for the Victron shunt), both purchased from Amazon. As noted in the photo below, I installed the Furrion Solar Port through the side wall of the driver's side of the trailer, just to the rear of the wheel well area and adjacent to the 30A power cord outlet. The Victron BMV-712 shunt is installed close to the battery, as depicted in the lower right corner of the photo.

Image: https://us.v-cdn.net/5021717/uploads/editor/1c/c9tbjqlg7dxt.jpg

I installed a couple metal "L" brackets in the floor (using 1/2" screws) to keep the battery aligned and in place. There really isn't a need to enclose the battery and it fits very well/snugly within the electrical compartment. I will likely replace my WFCO 8735P Power Center with one designed for charging a lithium battery.

Image: https://us.v-cdn.net/5021717/uploads/editor/58/kn490cszww2b.jpeg

Battery Disconnect Switch: I added a "Blue Sea Systems Battery m-Series" (Part #6006200) disconnect switch, also purchased through Amazon. After thinking it all through, diagramming all the wiring, and obtaining some additional input from @ScottG, the wiring process was fairly straightforward. I removed the wiring from the factory-installed disconnect switch in the aluminum tub, but left the switch in place. The new disconnect switch is installed inline between the WFCO Converter's +12V wire (red) and the battery's positive post using 10 gauge wire.

I also left in place the factory installed 10 gauge positive (red) and negative (white) wires between the electrical compartment and the front exterior junction box. The positive wire is connected directly to the battery. Therefore, assuming the battery wires are connected to the battery, power will be available for the emergency breakaway switch and brakes, regardless of whether the disconnect switch is "on" or "off."

Image: https://us.v-cdn.net/5021717/uploads/editor/3l/wuqhbyb18xsu.jpeg

External Solar Connection Port: I added a Furrion Solar Port (Part #FSPINS-BS), similar to the installation previously posted by by @DenisP. It took a little thought and planning to decide where to locate the external port. I wanted to locate it close to the battery and initially considered placing it directly above the 30A outlet, but the trailer's framework prevented that. I then considered the area adjacent to the front end of the driver's side wheel well, but that too was partially blocked by the trailer framework. I finally determined that I could locate it between the rearward driver's side wheel well/trim and the 30A electrical outlet, as depicted in the photo below.

Image: https://us.v-cdn.net/5021717/uploads/editor/pn/rd0zbgcznvgc.jpeg

I got a bit of a surprise when I pulled out the portion of the wall that I had drilled through - - a section of a hidden piece of galvanized steel was included with the Azdel, foam, etc., that I had drilled out. Since only a 1/2 circle portion of metal was cut out, I can only assume that my entry point was at the outer edge of a sheet of metal. I have never read/seen any mention of a sheet of metal in that area (i.e., adjacent to the 30A electrical outlet), so it definitely was a surprise. No harm, no foul, but if anybody has any idea as to why that metal is there, I would be interested in your thoughts. My best guess is that it is some sort of additional wall support.

Image: https://us.v-cdn.net/5021717/uploads/editor/1a/pm2glh3vjali.jpeg

Victron BMV-712 Installation: I installed the digital display screen for the Victron monitor above the Alde display. The location worked really well, because it allowed me to easily route the data cable up through the wall behind the television and Alde display.

Image: https://us.v-cdn.net/5021717/uploads/editor/vt/otipquj15y39.jpeg

Wiring Diagram:

Image: https://us.v-cdn.net/5021717/uploads/editor/k0/fv1hvrudy4rp.jpg

I recently returned from a trip to New Mexico and Texas, which gave me the opportunity to test everything and it all works as expected. I am very pleased with the installation and greatly appreciate the input offered by other forum members.

Denny16 · February 2022

Nice job Bayliss.
Cheers

Sharon_is_SAM · February 2022

@Bayliss Here is a VERY limited view of the driver side construction that I believe shows a thin, metal plate in the area behind the wheel. Probably just to allow them to add in electrical and plumbing before the side wall is added.

Bayliss · February 2022

Thanks for the photo, @Sharon_is_SAM I don't believe I have seen that particular photo previously, but it does indeed show a metal plate at that location, albeit in a later year model 320 S.

ReenieG · February 2022

Cherokee said:

Cool solution - storage space is always a rob Peter to pay Paul proposition.
We are lucky that we can get by with two golf cart 6v batteries in series - thanks mostly to portable solar and California sunshine.

@Cherokee do you find these work better than one regular 12v deep cycle? And do they both fit in the standard group 27 size battery box in your tub?

Bayliss · June 14

Over time, I have made some updates to the components and wiring within the electrical compartment of my 2019 320 S Boondock Lite, so I am posting the below wiring diagram and photos in the event they are of value to someone else.

My previous upgrade of the electrical compartment (below the driver's side bench) involved removing the OEM 12V battery from the aluminum tub and upgrading to a Battle Born 100 Ah LiFePO4 battery, which I installed in the electrical compartment along with the battery disconnect switch. Regarding the below wiring diagram, I confirmed that my 2025 Toyota Tundra 4x4 Crew Cab has an isolation relay, so the 12V+ wire from the truck via the 7-way power cable is wired so that power to the trailer is provided when the truck ignition is "on", but disconnected (and not back-feeding to the truck battery) when the ignition is off, even if the 7-way cable remains connected.

Since February 2022 (see previous posts above), I have added a Victron MPPT 75/15 Solar Controller, Renogy 220W Solar Suitcase, Progressive Dynamics 4135K Power Center/Converter, DC Terminal Block (for better DC wire organization), positive "+" and "-" busbars, and a "Tire Tracker" TT-600 TPMS Signal Booster to monitor the trailer tires air pressure. Those changes were all done some time ago, but I never got around to preparing a wiring diagram. I have now completed the diagram, so it seems like a good time to post the information.

UPDATE (06-15-2025): After re-reading this entire discussion thread, I recall that I had been seeking assistance on how to get power to the battery from its original location in the exterior aluminum tub, to the interior driver's side bench electrical connections compartment. Additionally, I wanted to ensure that 12V power was available to the electric brakes. Both turned out to be very simple, because the "+" and "-" wires from the Junction Box had already been routed to the electrical compartment (and on to the converter) during construction of the trailer by nüCamp. Again, if it is of value to anyone thinking of relocating their battery in an earlier model year T@B, I prepared additional diagrams to separately depict/highlight the paths of the 12V+ charge line to the trailer battery, and the path of power provided by the trailer battery to the electric brakes and interconnected breakaway switch (see below.) An expanded view of the Junction Box ("J-Box") wiring is included in my November 2021 post earlier in this discussion thread.

Image: https://us.v-cdn.net/5021717/uploads/editor/tv/07cztxswz2fo.jpeg

Cherokee · June 14

I've been Boondocking for years with two 6v AGM's , a NorCold 180.3 (3-way) and a 95w Zamp solar suitcase. Though I have to occasionally read a thermometer and make an adjustment, this combination is a great set -up for camping off-grid for prolong periods. One propane tank and the batteries:

Image: https://us.v-cdn.net/5021717/uploads/editor/sb/x5zqwkbnfndf.jpg

deepsea5 · June 20

Bayliss said:

Over time, I have made some updates to the components and wiring within the electrical compartment of my 2019 320 S Boondock Lite, so I am posting the below wiring diagram and photos in the event they are of value to someone else.

My previous upgrade of the electrical compartment (below the driver's side bench) involved removing the OEM 12V battery from the aluminum tub and upgrading to a Battle Born 100 Ah LiFePO4 battery, which I installed in the electrical compartment along with the battery disconnect switch. Regarding the below wiring diagram, I confirmed that my 2025 Toyota Tundra 4x4 Crew Cab has an isolation relay, so the 12V+ wire from the truck via the 7-way power cable is wired so that power to the trailer is provided when the truck ignition is "on", but disconnected (and not back-feeding to the truck battery) when the ignition is off, even if the 7-way cable remains connected.

Since February 2022 (see previous posts above), I have added a Victron MPPT 75/15 Solar Controller, Renogy 220W Solar Suitcase, Progressive Dynamics 4135K Power Center/Converter, DC Terminal Block (for better DC wire organization), positive "+" and "-" busbars, and a "Tire Tracker" TT-600 TPMS Signal Booster to monitor the trailer tires air pressure. Those changes were all done some time ago, but I never got around to preparing a wiring diagram. I have now completed the diagram, so it seems like a good time to post the information.

UPDATE (06-15-2025): After re-reading this entire discussion thread, I recall that I had been seeking assistance on how to get power to the battery from its original location in the exterior aluminum tub, to the interior driver's side bench electrical connections compartment. Additionally, I wanted to ensure that 12V power was available to the electric brakes. Both turned out to be very simple, because the "+" and "-" wires from the Junction Box had already been routed to the electrical compartment (and on to the converter) during construction of the trailer by nüCamp. Again, if it is of value to anyone thinking of relocating their battery in an earlier model year T@B, I prepared additional diagrams to separately depict/highlight the paths of the 12V+ charge line to the trailer battery, and the path of power provided by the trailer battery to the electric brakes and interconnected breakaway switch (see below.) An expanded view of the Junction Box ("J-Box") wiring is included in my November 2021 post earlier in this discussion thread.

Good morning Bayliss,

Thank you very much for your detailed explanation of how you relocated the battery. My wife and I recently purchased a 2021Tab 320 Boondock and plan to relocate the battery in the same place you chose. The Newitpower 300 AH battery I ordered just arrived and it will be able to be "shoehorned" into the same location as your Battleborn. Hoping to start the conversion in a couple weeks or so, depending on weather and work. Looking forward to retirment and relocation to the Tucson AZ area in 2026!

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Lithium or AGM Battery Mounted Inside a 320 Cabin?

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