Lithium or AGM Battery Mounted Inside a 320 Cabin?

CrabTab · February 2020

Has anyone installed a lithium or AGM battery inside of their 320? If so, how did you secure the battery? We are thinking under one of the benches may be possible. Thoughts? Advice?

DougH · February 2020

@CrabTab, I have a couple AGMs in the passenger back compartment under the bench. I screwed big hooks into the center wood structural members, and used ratchet straps around the batteries. They've never moved. Naturally it will lighten your tongue weight a bit, so compensate appropriately.

ScottG · February 2020

IIRC this topic has come up a few times in the past, though not so much recently. If you haven't already, you might try doing a search for some additional insights.

rfuss928 · February 2020

Many models of the DM T@Bs had the batteries mounted under the bench or bottom of the closet. They used vented boxes as do many RVs.
I have dual AGMs in the bottom of our CS closet.

Image: https://us.v-cdn.net/5021717/uploads/editor/iv/su794n6t7ud2.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/ow/r0e9yvzf4szl.jpg

Denny16 · February 2020

Nice, and using this or a Marine type battery box works well, and protects th battery terminals from shorts.
cheers

CrabTab · February 2020

Good info so far! I was thinking the best anchor point would be the interior woodwork. Your experiences show this to be a sound thought.

Tundra57 · March 2020

Lithium batteries have a much higher storage density than AGM batteries. So for the same size you get more electrons. However they are much more expensive and if overheated can burst into flames, Lithium is very poisonous too.

Cbusguy · March 2020

Not sure why you would want to put it inside the trailer. keep them warm maybe, but some 5 watt automatic tank heaters will do that for cheap.

A quality name brand lithium iron battery has about the same fire potential as a lead acid battery. The internal BMS will stop anything crazy from happening.

Keep in mind there are a lot of chinese no name batterys showing up on amazon, ebay and aliexpress for a couple of hundred bucks less than renogy, Lion or Battleborn. reviewer have shown that they rarely deliver advertised capacity, use recycled cells and the BMS's are not at the same standard as the big three.

My concern is a newbie in a hurry will come to this forum save a few bucks on the lithium battery, throw it in under the bed in quickie, get by with it manner and burn their trailer down. Please do your research before installing any lithium chemistrys

VictoriaP · March 2020

Cbusguy said:

Not sure why you would want to put it inside the trailer. keep them warm maybe, but some 5 watt automatic tank heaters will do that for cheap.

Three other potential reasons off the top of my head: reduce tongue weight, to free up space to add something else to the tub like another propane tank, or to protect expensive batteries from easy theft. I’ve thought about doing it, but this project is down the road a ways for me.

I hadn’t seen the cheaper lithiums yet, a bit scary! Some things are worth buying only from reputable known brands.

Cherokee · March 2020

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.

Bayliss · November 2021

Reviving this thread and seeking some input/ideas from others, piggy-backing of @CrabTab's original question:

Three reasons why I am considering this are (1) upgrade my battery and create a shorter wire run from the battery to converter (which I will also likely upgrade for lithium charging, plus add a portable solar suitcase); (2) free up space in my aluminum tub to add a second propane tank; and (3) possibly swapping out my 3-way Norcold refrigerator for a 2-way refrigerator.

Specifically, I am interested in possibly installing a Renogy 100 Ah Lithium battery (Group 31) inside the electrical wiring compartment area on the driver's side of my 2019 320 S. [I have also considered a different brand 125 Ah AGM, but am currently leaning more toward the Lithium.] I have not fully explored it yet, but I believe (hope?) I will be able to move aside the wires in that compartment enough to make space to set the battery on the floor (although nuCamp made some of the wire runs tight with little slack. I am also hopeful that I can leave the hot and cold water lines as is. The battery would be oriented front to back (i.e., ends of the battery facing toward the front and rear of the trailer.) May be a very tight fit, or an impossible fit, but I probably won't know for sure until I start moving the wires around. If all else fails, I'll put the lithium battery in the aluminum tub OR consider installing it in the passenger side interior storage compartment (under the bench.)

I am also interested in the best way to move the battery cut-off switch to that area, mounting the switch knob on the outside of that storage cabinet, facing inward toward the open floor area under the bed. What would be the best way to go about that (i.e., cutting in to the wires that run from that compartment to the current battery location in the aluminum tub)?

Any input or suggestions is greatly appreciated. (Greg)

Denny16 · November 2021

Greg, you need to trace the wires from the current battery a d find where they come out under the bench, probably next to or near the Waco power converter. The battery switch goes between then positive battery cable to the 12VDC load source (power converter? Some of nüCamp’s early wiring was a bit of unorganized looking. You might start by looking up,wore management practices.

I added a marine power distribution buss on some of the 12 VDC runs to the battery, with a single connection to the battery, on both the positive and negative side, to clean up my Victron 712 install. See: https://www.ebay.com/itm/274922240552?chn=ps&_trkparms=ispr%3D1&amdata=enc%3A1aZtaO1OrRj6Ra4cc3d0S6w80&norover=1&mkevt=1&mkrid=711-213727-13078-0&mkcid=2&itemid=274922240552&targetid=4580702890871448&device=c&mktype=&googleloc=&poi=&campaignid=418640321&mkgroupid=1233652283797640&rlsatarget=pla-4580702890871448&abcId=9300602&merchantid=51291&msclkid=9418d184f4ee13b71a2db00847ea13a3

Other members here have moved the battery inside the TaB320 under one of the benches, so it can be done. Getting the wire runs worked out is the hardest bit, and a good place to start, labeling the wires as you work,out what they are for and where to go to/from. A diagram can help organize this also.

Here is the wiring diagram for a 2019 TaB320 showing Battery switch connection between the battery (circled in red at bottom) and the connection block under the front of the trailer. From there it goes inside the trailer to the Waco power converter. Good luck. cheers

CrabTab · November 2021

I probably have too many thoughts on this @Bayliss.

Somewhere on the forum I saw a post where lithium batteries were placed in the area behind the Alde. I believe it was 200AH and over 300W of solar on the roof.

I thought about making a raised platform in the cabinet you're looking at to avoid the plumbing and electrical running along the floor (using blocks to lift it off the floor and secure the platform to the cabinetry). Getting a different cutoff switch that could mount a bit more flush to the cabinet might be nice.

Anecdotal evidence from posts by those with 2 way fridges suggests that more than 100A may be preferable if you do lots of dry camping.

Two propane tanks is a lot of gas, especially without a 3 way fridge. Our longest voyage so far was 5 weeks. Two weeks in we topped off the gas in Minnesota and returned home with more than half a tank of gas. We perked coffee every morning, cooked dinner most days, dry camped about 60% of the time (using gas for the fridge) and ran the Alde on gas about 10 nights. Also, there are places to fill or swap out tanks everywhere we've been in the US.

Ultimately I kept the battery in the tub to keep the tongue weight from getting too light. Although, a second gas tank would offset that issue.

Looking forward to reading how you solve the 'problem'. It may inspire me to rethink my choices.

Bayliss · November 2021

@Denny16, thank you for the suggestions and diagram. I have a copy of @klenger's diagram and have made my own of the junction box wiring, so those, along with your suggestions, and those of other forum members, should help me get the wiring right. I just have a bit of wire tracing to do. I recall someone on the forum moving their cutoff switch to that compartment, but there was some question as to whether it was optimally wired. I am going to try and re-locate that discussion.

@CrabTab, thank you as well for your input. Last night, I read your posts about ultimately deciding to go with an AGM and keeping it inside your front tub. That is another option I am considering and have been looking at a VMAX 125 Ah AGM for that option. I really like your idea of purchasing battery terminal covers and plan to do that, regardless of where I ultimately install the battery. Your "raised platform" idea is interesting and worthy of consideration. I had not even thought about doing something like that. I also reviewed your post about your tongue weight findings, which is extremely helpful, so thanks for that.

Your point about the extra propane tank is well taken. We dry camp for extended periods at times, plus we spend most of our time outside. Therefore, we usually carry a second tank, because my wife uses a larger three burner stove for cooking, so we use the tank for that and our outdoor BBQ. It usually lasts a couple weeks or more, depending on the amount of use. As far as the impact on tonque weight, in addition to the propane tank off-setting the weight of our current lead acid battery, we have the Boondock spare and a Jack-IT bike rack mounted on the tongue, so I am right about where I want to be as far as tongue weight.

I don't specifically recall the discussion you referenced regarding placing lithium batteries behind the Alde compartment, but @rfuss928 posted photos (see above in this discussion) depicting how he mounted dual AGMs in the bottom of his Dutchman CS closet. He also moved his cutoff switch to that area, so maybe he will chime in with his thoughts if he sees my comments. That closet appears to show the curved wall at the front end of his trailer. That location looks much like the curved area at the rear of my (and your) 2019 320 S Boondock. I don't store much in that area (due to the accessibility issues), so I am now thinking that may be an ideal location to install a lithium battery. It would also likely allow me the option of installing up to a 200 Ah lithium battery. I just need to go to my trailer (it's in storage) and measure that compartment.

FINALLY (sorry for the lengthy response), going with a larger battery (above 100 Ah) is definitely on my radar IF I install a 2-way refrigerator. I am actually somewhat conflicted about replacing my refrigerator. Unlike several T@B owners who have the 3-way, mine has always worked well. However, it does have a hard time staying cool when the ambient temperature is in the 90s+. Therefore, if I keep the 3-way model, I will likely add two external fans to help cool the refrigerator, so a 100 Ah lithium, or 125 Ah AGM battery should be sufficient. My biggest issue with the 3-way is that I don't run the propane while driving, and the battery does not keep it cold while towing, so I am hoping that adding fans would solve that problem, but that is a discussion I need to raise on a separate post. [NOTE: This is a project I will be working on over the next several months in anticipation of taking a long cross-Canada trip later in 2022.]

ScottG · November 2021

@Bayliss, I can't offer much wisdom regarding internal battery installation, but below are some photos of my cut-off mounted in the location you describe. Installation is pretty simple--you just place the switch within the main line between the battery and the power center.

A good crimping tool is handy for adding ring terminals and extending wires as needed. By planning my cuts carefully I only needed to add ~12" to the wire on the converter side.

If you are moving the batteries inside, the bigger challenge may be retaining the ability of the tow vehicle to charge the batteries while in transit. Since you will probably be adding a new positive lead from the battery to the switch, perhaps you can repurpose the old battery lead from the forward junction box as your new charge line. There is also the issue of maintaining power to the breakaway brakes, but at first pass I think that same line could serve both purposes.

Image: https://us.v-cdn.net/5021717/uploads/editor/u4/ghatex17l9q8.jpeg

Image: https://us.v-cdn.net/5021717/uploads/editor/o5/2o3ybfk8devk.jpeg

CrabTab · November 2021

@Bayliss

I guess my memory was a mashup of this post 350 watt solar 200 ah lithium battery install on 2017 CS (vanillacommunity.com) and what @rfuss928 said earlier in this discussion.

@ScottG is showing exactly what I meant about the cutoff switch. He must have posted that photo previously and it imprinted on my brain. Considering his comment about the trailer emergency brakes. My box type trailer (car hauler) uses something similar to this Amazon.com : trailer brake battery box

We don't use the fridge on propane while moving either. Our experience sounds similar to yours too. We (usually) like the 3 way when dry camping. There was one July near Daytona Beach, FL when I said a few 'Navy words' at it though. I've thrown a lot of time and money (mostly because its fun) at the fridge. 200W of flexible panels on the roof, along with the trickle charge from the 7 pin seems to keep the fridge running on DC while on the road without killing the battery.

We also bought a portable electric fridge along with a power supply that rides in the back of the truck. It replaced our trusty Yeti cooler. After using this past season, it is complete overkill, but I guess does double as 'SHTF supplies' (oh well its only money, right?!).

Again, looking forward to seeing the progress when you start working on this in earnest...

Bayliss · November 2021

@ScottG, thank you very much for the photos (with arrows, no less.) They are very helpful. I also like your low-profile cut-off switch, as also suggested by @CrabTab.

I have previously considered the need to not interfere with the external break-away switch operation and unimpeded battery connection, so I think my best approach is to do as you have suggested and connect the new (relocated) battery using the same wires that currently lead from the external battery disconnect switch. I would cut those wires at the best location inside the electrical compartment inside the trailer and simply cap off the (original, but then unused) wiring leading to the outside cut-off switch. I would leave the original wires and cut-off switch in place in the event I or a future owner opt to revert to putting the battery back in the aluminum tub. @CrabTab, I'll post the result of what I ultimately decide to do. It's the least I can do in exchange for the helpgul input from others.

ScottG · November 2021

If I understand you correctly, I think that would work, @Bayliss. The current connection between the battery and the power center is made through the forward junction box on the second pin from the right.

If you connect the wire labelled CONVERTER directly back to the relocated battery, your battery will always remain connected to both the trailer pigtail and the breakaway brakes. A new second line from the relocated battery could run to the converter via the new internal cut-off. This is essentially how my set-up works--the cut-off switch disconnects the battery from only the converter, so its position has no bearing on charging from the tow vehicle or powering the breakaway brakes in the event of a complete trailer separation.

Using this configuration, I would probably disconnect the BATTERY line from both the positive and negative (rightmost) pins. This would ensure that the unused wires running back the tub (and the old cutoff switch) never get inadvertently energized.

Image: https://us.v-cdn.net/5021717/uploads/editor/7d/dl4nu8gz8rbs.jpg

Denny16 · November 2021

You can move where the 12VDC battery is located, as long as the battery is still connected to the original Red/White #10 Battery connection going to the junction box under the front of the trailer.

As long as the battery terminal still has power from the battery, the break-a-way switch will still work, as will the TV charge connection. Just find inside where the battery wires run to, and wire the battery and battery switch to the wire run inside the trailer, connecting the wire that comes from the front to the new battery connection inside the trailer.

Cheers

Bayliss · November 2021

@ScottG, you are correct in your understanding of what I had concluded. However, while you were likely writing your most recent comment, I was thinking about the GROUND wire connection between the battery and the multiple 12V ground wire connections in the junction box (i.e., the #7 terminal at the far right in the photo you included above.) Specifically, as I have drawn in my junction box wiring diagram below, and as you have perceptively noted, one of those ground wires connects directly between terminal #7 and the negative side of the battery.

What I was thinking is that I can leave the battery positive and negative connections in the junction box as is, but tie in to both of those wires by splicing to them at or near the current external cut-off switch. As currently configured, the red (hot wire) is routed through that switch and continues on from there to the external battery. From what I can see without removing any wire split-loom in the area of the external cut-off switch, the white (ground wire) is routed adjacent to the red wire, but continues on directly to the negative side connection of the battery.

My biggest task would be to route the external battery ground wire back inside the trailer to get it to the new battery. This would accomplish what you have pointed out, which is the need to remove the external switch from the equation. It is also consistent with @Denny16's most recent response.

Does that make sense?

Image: https://us.v-cdn.net/5021717/uploads/editor/eb/y776vcuvpcyo.jpg

rfuss928 · November 2021

My CS originally had a single battery in a sealed box in the bottom of the closet. I installed a couple wood risers to allow two of those boxes to be mounted longitudinally and bottom vents plumbed together and vented out the bottom. There was not a disconnect switch originally. The switch shown is a battery selector switch allowing either, both or no battery connected. There is also a shunt for a remote analog amp meter which shows entire 12V system usage and gains. The small rectangular meter is solar gains.

Image: https://us.v-cdn.net/5021717/uploads/editor/tz/22zinr0oh5tz.jpg

Denny16 · November 2021

@Bayliss Greg, you do not need to route new wires from the battery back to,the front terminal block where he 7-pin is wired. You already have a Red and White No10 wire that goes from the front connector to inside the TaB. My thought is find the red wire, cut it and add a 3 or 4-point terminal buss, with the red wire connected at the ends.

Then add your Battery connection from the cut off switch to one of the center connections. The battery ground can be routed directly to the ground buss behind or next to the Waco, the white ground wire is already connected to this ground buss and now you have the battery connections inside, and the factory connections are still in place going to the 7-pin terminal strip.

The new positive buss you are adding will distribute the loads between inside and the front, and the original ground buss does the same. Everything is connected at a central point, then going to its various components. This eliminates any ground loop issues, or any single wire being overloaded.
cheers

Bayliss · November 2021

@rfuss928, thank you for the clarification about your install. Your "command center" looks pretty high tech!

Bayliss · November 2021

Thanks @Denny16. I think my brain is fried tonight after pondering this and related subjects all day, so I am going to have to digest what you have suggested, which I appreciate.

I understand what you are saying in regards to the connections at the WFCO power center, but my initial impression was that I still need the battery ground running directly between the battery and the junction box to complete the loop, particularly for maintaining the connection for the electric brakes. Otherwise, why did nuCamp wire it that way? If I understand your suggestion, I would be "incorporating" (utilizing?) another (already wired) ground wire connection between the interior ground buss bar and the exterior junction box. Maybe I am simply overthinking it and the ground connection will work fine as you have suggested. I just need to think it through while mapping out the circuits. Again, thanks for the helpful input.

ScottG · November 2021

@Bayliss, I confess I'm getting a little lost... As far as the 12VDC negative (a.k.a., "ground") is concerned, I would just connect the negative side of the relocated battery to the 12VDC negative bus adjacent to the power center. The bus is already tied directly to the power center and to pin 7 of the forward junction box, so no other modifications are required.

In summary, here's what I'm suggesting. Except for the last item, all of this would be done in the power center compartment under the driver's side bench. FWIW, I've attached a quick sketch of this below:

Cut the existing 12VDC+ line from pin 6 on the forward junction box. On the junction box side, splice in a 30A fuse and add a ring terminal. Connect this to the positive side of your relocated battery. (This will ensure that the tow vehicle charge circuit and the breakaway brakes are always connected to the battery.)
On the power center side of the cut 12VDC+ line, add a ring terminal. Connect this to the load side of your new disconnect switch.
Assemble a third wire with a ring terminal on both ends and a 30A fuse in between. Use this to connect the positive side of your new battery to the battery side of your new disconnect switch.
Connect the negative side of your new battery to the existing 12VDC- bus as described above.
Disconnect or cap the old battery leads from pins 6 and 7 in the forward junction box, but leave them in place should you even want to return the battery to it's original location in the tub.

You could incorporate variations on this--for example, running everything through the new disconnect--but this seems to me to be the simplest and most foolproof configuration.

I think this is basically the same as what @Denny16 is suggesting. I agree there is no need to run additional wires into or out of the trailer purely for the sake of relocating the battery.

Image: https://us.v-cdn.net/5021717/uploads/editor/wf/7a6aq2otwaai.jpeg

Denny16 · November 2021

Looks good, except you left the 7-pin connected hot so the battery disconnect does not disconnect battery from 7-pin junction/harness. This could be a potential short issue if the 7-pin gets wet during storage. Also could lead to a dead battery if the emergency brake-a-way cable gets inadvertently pulled out, setting the trailer brakes. The connection back to the 7-pin needs to be on the battery disconnect switch load side, so it gets switched off. This is how the OEM setup works.

Scott you got the idea, but take your fused, direct connection to the 7-pin off the battery, and move it to the load side of the battery disconnect switch:

Move 7-pin connection from battery and connect to battery switch, see blue line above.

This eliminates the second fuse, as the fuse on the battery to switch side will be sufficient, and will also protect the 7-pin connection. This is how the TaB400s with internal batteries are setup.
Cheers

ScottG · November 2021

@Denny16, if you read the description provided with the diagram, you will see that I intended to leave the pigtail hot. The OEM setup in my 2015 didn't even have battery cutoff, so everything was hot all the time. As I've said previously, I like the fact that I can disconnect my battery from the power center while leaving the tow vehicle charge circuit and breakaway brakes connected.

At the end of my previous post, I did suggest the alternative of running everything through the disconnect. You raise some good points about shorts in the pigtail and accidental dislodging of the brake pin, but in seven seasons of T@bbing those have not proven to be real concerns for me. YMMV!

Denny16 · November 2021

Thanks Scott, missed that bit in your description…. Your point is very valid, but newer TaBs have the Battery Switch isolate these connections, which is why hat I am going by. Not everyone is going to be as careful with their trailers as you have been.

cheers

SLJ · November 2021

Moved my AGM battery inside under the bench by the door directly over the axle. Lightened the tongue and less of a chance it will be stolen when the T@B is left unattended for a day or two while we're canoe tripping. Main shut off and the connections were left in the front box inside a weatherproof box and just ran heaver gauge wire through flex conduit to under the bench. Battery box is vented through the floor and bolted down. 30A fuse on positive terminal.

Image: https://us.v-cdn.net/5021717/uploads/editor/8i/rtmdd6cbb3ug.jpg

Bayliss · November 2021

@ScottG and @Denny16, thank you both VERY MUCH for the clarification and wiring diagrams, which are extremely helpful. I didn't even think about simply wiring the battery ground wire directly between the relocated battery and the inside ground buss bar. Such a simple solution. Stupid me!! I must have really been tired while over-thinking it.

@SLJ, your relocation of the AGM battery is a nice solution. I am also considering that as a potential place to locate my new battery, but I have made good use of that storage space thus far and hate to give it up. I am currently leaning toward locating the lithium (likely a 200 Ah) in the far driver's side far rear curved storage area. It is pretty much a useless location for easy-access storage, but great for a lithium battery since it does not matter how I position it. Essentially, it will end up on its side at about a 33-degree angle. I took some measurements of that area on Thursday, but am currently on the road for a week (without the trailer) and have not yet had a chance to compare those to the battery measurements to determine if that area will in fact work.

I am pretty confident that a 200 Ah lithium will be too big for relatively effortless placement in the electrical wiring compartment on the driver side of the trailer. I am also leaning toward switching out the 3-way refrigerator for a 2-way, especially if I go with the 200 Ah lithium. My current 3-way fridge does not stay cold while towing on battery only (I don't want to run the propane while driving) and that is where I am finding the biggest downfall with the 3-way. Otherwise, I have not had any issues with that refrigerator.

Again, a BIG thank you to everyone who responded to my question. Love this forum. Greg

jkjenn · November 2021

I am a little late to this, but @Bayliss, I installed 2, 100ah lithium batteries in my 2021 T@b cabin. I have a post with details and a video, here: https://jenngrover.com/whats-new-with-mattie-ross/

Howdy, Stranger!

Quick Links

Categories

Lithium or AGM Battery Mounted Inside a 320 Cabin?

Comments