Mounting Lithium Batteries Under RV Floor: Feasibility and Best Practices

[FiveOclcok]

Got a crazy question! Anyone ever thought of putting batteries underneath the travel trailer?
I was running new electrical wire in my 2026 Grand Design imagine 2920 BS, when I noticed how much space was beneath the foor of the RV but above the under skirting. I have about 10 in of vertical space and about two or three feet in between each beam of the chassis of the RV. It is mostly full of ductwork and wiring, but plenty of room to probably put 15 or 20 batteries if I wanted to. Then there is a protective sheet of cardboard like material that gets screwed to the main chassis encapsulating everything. I was wondering if I could bolt or weld on a Shelf that would hold the rack type batteries. My problem is not necessarily room, but weight distribution, I need to get the batteries in the back near the tires because I have way too much hitch weight. I think even maybe 3 ft would help. I'm running a 48 volt system so I can oversize the cable coming from the batteries to all the other equipment that is in the compartment on the front of the RV. Has anyone ever thought or know anyone that's done this?

 

[Mark_K5LXP]

I've done it on a truck camper. It wasn't ideal because I didn't consider ease of access for service and I didn't adequately protect it from the environment.

Even 'maintenance free' batteries need tending and protection so provided you can accommodate that, and you're mindful of weight, then this can work. How you effect this short of putting a hatch in the floor I'm not sure but maybe you have a plan.

Mark B.
Albuquerque, NM

 

[John From Detroit]

Was watching a video.. Jeep (Grand Cherokee) and Dodge Durango if you are someone riding shotgun they are sitting on the battery. It's under the passenger seat... Lots of fun if you need a new one (Access is not easy) (If I need a new battery I'll get it replaced not DIY But I needed to add some connections to the battery.. Kind of fun doing that too but at least it is well placed as the device I power "Battery direct" is under the Driver's seat (ICOM ID-880H).

Just tossed it in for the humor part.

 

[Ex-Calif]

As long as you engineer the shelf, consider venting and servicing it should be no problem.

4 to 6 batteries weigh a lot. Add g-shock loads from potholes and road hazards and make sure the shelf won't fail.

Car makers have put batteries in all kinds of (inconvenient) places

 

[PancakeBill]

With 48v system, i assume you are using LiFePo batteries, so venting is a non issue. Also orientation is a non issue. Some means of shock absorption on the shelf and closed back up.

Mark mentions it in a TC setup, friend of mine back home (RI) did that in the underside of the truck bed, and that was with LA batteries.

 

[John From Detroit]

As long as you engineer the shelf, consider venting and servicing it should be no problem.

4 to 6 batteries weigh a lot. Add g-shock loads from potholes and road hazards and make sure the shelf won't fail.

Car makers have put batteries in all kinds of (inconvenient) places

Oh yes.. Dodge/Jeep is not the first to put 'em, under the seat. Not by a long shot

 

[FiveOclcok]

I wonder if anyone has ever installed the entire system outside. If there were a waterproof enclosure that could be mounted on a rack using the RV’s existing hitch, it might be an option. That would likely require a significant amount of engineering, but I need to find a way to reduce the weight on the trailer tongue.

 

[PancakeBill]

What type batteries are you using?

 

[Primerump]

I wonder if anyone has ever installed the entire system outside. If there were a waterproof enclosure that could be mounted on a rack using the RV’s existing hitch, it might be an option. That would likely require a significant amount of engineering, but I need to find a way to reduce the weight on the trailer tongue.

I implemented a small system years ago with an aluminum toolbox holding two T105's, one MPPT controller and a small 1500W inverter. I had to include a fan to vent the box. this was mounted on the tongue of a TT.
the main issue for such a system is water ingress. even with an active fan vent, the owner reported corrosion on the inverter terminals after a few years due to the batteries venting. lithium would not have the same effect of course. if you have room for a larger enclosure on the rear of the rv then it may be possible. loading the rear hitch mount or other support on the chassis may require some additional bracing.

other methods to reduce frontal weight might include a "big ass" helium balloon.. ! LOL

 

[John From Detroit]

My Portable system today is LI in a box but if I was using Lead Acids the "Electronics" and the battery would be environmentally isolated. You explained why.

My Battery box has two LiFePO4s in it a main and a secondary. Got the change over switch last weekend. Now to get the round tuit.

 

[SargeW]

As already stated, most TT have batteries mounted outside on the tongue usually in a plastic box. Lithium doesn't require venting for off gassing like lead acid, but some ventilation for heat generated from heavy loads is a good idea. Also they don't require much maintenance, but being able to check the cable snugness from time to time is recommended. RV's do tend to bounce quite a bit on our not so smooth roads.

Sometimes the "out of sight, out of mind" situation is not always a good thing.

 

[FiveOclcok]

I'm using 48 volts lithium redodo batteries, does lithium ion batteries have to sit straight up could I lay the ones that I have on the side instead of buying new ones?

 

[SargeW]

Usually laying them down is not a problem. Unless the manufacturer has a restriction on that, but usually not. As long as the BMS in the battery doesn't get crushed, the cells are pretty solid.