Relocating Batteries

[climb_on]

I am moving my pair of Costco Golf Cart Batteries from the tongue, to the rear of the camper under the bunk area. Primary reason is to get my tongue weight down a little bit. I've done all the calculations and scales visits and this is a good solution to keep me in the 900-1100 or 12%-14% tongue weight range.

So I would obviously need to put the batteries in a sealed, secured and vented battery box top and bottom - no problem. The new battery location would be located right next to the charger/converter, so wiring would be very convenient. This pic shows the new location.



Question: Is rewiring the batteries in a new location, as simple as I think it is? Battery negative bonded to the frame and Battery Positive to the 2nd lug of on the charger/converter circuit board (see picture)? I would also add a battery disconnect near the new battery location, like we have up front.



Also, there are electrical component wiring (emergency brake, tongue jack,etc) at the old location on the tongue that I think will still operate as long as I leave the existing positive battery cable in tact. I will leave all the existing wiring to the front, in tact anyway, as to easily return to the original setup if desired and to keep power to the front junction box. Is there something I am forgetting to consider here?

[myredracer]

FW trailers have vented battery boxes in the storage compartment from the factory so it obviously works just fine. The upper vent must be a minimum of 6" above the top of the battery box. If you have an enclosed underbelly, I would avoid having the intake on the bottom simply going into cavity. It is possible in some conditions (temp. & pressure differential between inlet and outlet vents)to have reversal of the air flow and you don't want hydrogen to get into the enclosed space and back inside the TT. Getting the vent 6" above the box may be difficult under the bed. The MTS box is 10" tall you would need a minimum of 16" of vertical space.

A problem with the sealed battery box that is used in RVs (as in the photo) is that it is a bit of a PITA to check fluid level in the batteries. They used to have the upper piece held in place by nuts/bolts all around but they have at least changed that to clip-on fasteners. Still, not the simplest to get off, put back on and to ensure the foam seal is okay. And if you are mounting the boxes in a not-so-easy location to access, it will make it even harder to check the batteries.

I would definitely use sealed AGM batteries for this. You would need to confirm that your converter is compatible with AGM batteries. AGM batteries can off-gas if overcharged so I would still use a vented box for them.

You could consider installing a new exterior door to access the batteries so that they are easier to get to. Doors are available here for example: Challenger Door

Before you do anything, if it were me, I'd go to a scale and temporarily sit the batteries in the rear of your TT and see how much the tongue wt. actually does change.

[climb_on]

Extra thanks to those who those members who have provided the requested feedback about wiring details, those who have actually done this mod or had them inside from the start - I appreciate it! I will try to post pics of the completed mod soon...I will be completing it this weekend.

[hddecker]

Lantley wrote:
Seems like a lot to go through just to reduce TW.
I would either move other cargo not batteries to rear store and go . Or build a rear platform for back of trailer.
The batteries are kept outside of the living space for a reason. Why put them into a living /sleeping area. There is a risk associated with the batteries. I would seek a different solution.

Moving the batteries to the bumper makes a whole lot more sense to me.

There have been several campers over the years that have had batteries in sealed boxes inside the unit. But in my mind that just becomes one more maintenace item and a very critical one, maintaining the battery box seal.

One battery blowing up in you face is one too many.

[kevden]

I moved the batteries on out TT last year from the tongue to underneath the TT under the kitchen where the power center is located. I was planning to mount the batteries inside the cabinet under the sink, but I was concerned about the safety and lost storage space. I ended up making a frame for 2 agm batteries out of steel angle from an old bed frame and mounted it underneath the floor between the frame of the TT and the skirting. I did this to power an inverter which I mounted under the sink. I did the wiring just as you described and simply removed the battery leads at the tongue. I left the disconnect switch in place on the tongue to turn off power to the jack when needed, and placed a new breaker/disconnect at the new location. My plan is to install a mesh floor to the underside of tongue to store wheel chocks and leveling blocks.

[kevden]

I moved the batteries on out TT last year from the tongue to underneath the TT under the kitchen where the power center is located. I was planning to mount the batteries inside the cabinet under the sink, but I was concerned about the safety and lost storage space. I ended up making a frame for 2 agm batteries out of steel angle from an old bed frame and mounted it underneath the floor between the frame of the TT and the skirting. I did this to power an inverter which I mounted under the sink. I did the wiring just as you described and simply removed the battery leads at the tongue. I left the disconnect switch in place on the tongue to turn off power to the jack when needed, and placed a new breaker/disconnect at the new location. My plan is to install a mesh floor to the underside of tongue to store wheel chocks and leveling blocks.

[qtla9111]

I wonder why rv manufacturers put batteries inside in a vented box. I've had three TTs with batteries inside. One was in a closet in the bedroom, the other two were located under the kitchen sink in the cabinet. All three had a plastic box with a hose attached to the side with a small round vent cover. I know the rv industry is highly unregulated but if it were so dangerous would they be allowed to get away with it this long?

That said, I too want to do the same thing. My TT is tongue heavy. I want two additional batteries and move all of them to the rear using a reinforced bumper and a long battery box. Also, to change the LP tanks to the underside like on a Class B or C and then use the hitch for an encased generator.

They don't make them the way I want, so we'll just make it the way I want. Anything is possible and in some cases it has a cost associated with it. We are on the road a lot and we are boondockers.

I think the OP has a great idea and I hope he continues with his project. It may require some consultation from experts including a call or emails to the manufacturer.

[Lantley]

Seems like a lot to go through just to reduce TW.
I would either move other cargo not batteries to rear store and go . Or build a rear platform for back of trailer.
The batteries are kept outside of the living space for a reason. Why put them into a living /sleeping area. There is a risk associated with the batteries. I would seek a different solution.

[westend]

You will need to either make a sealed and vented box in that location or buy one. You can't use the typical black plastic battery boxes and vent the area that they sit in. If you proceed with that, you'll have the explosive hydrogen and corrosive hydrogen sulfide free to work it's destructive magic. One spark in the area when those gases are present can ignite the gas mixture.

You should also do some side-to-side weight measurements to make sure this is a viable weight transfer.

FWIW, I have two GC2 6v's inside a box located just in front of my axles, inside the cabin. The box I made for the batteries is gasketed/sealed and vented to the exterior.

You may need to upgrade the wire to the tongue to operate the jack but I don't know the specifics of the load and your wiring. Fuse the positive lead from your new battery location at the batteries.

[hddecker]

I saw first hand what happens when a battery blows up, just about lost an eye when it blew.

Yes you can probably do it and not have a problem, but what happens if your trailer blows up or burns, just the sort of thing an insurance adjust could use to deny the claim.

[brulaz]

My old trailer had two golf cart batts in a vented box inside. No problems.

I mounted the battery box with bolts through the side walls, not the bottom, so any battery leakage (and there definitely was some) collected on the bottom of the box and didn't drain into the trailer.

Later noticed that the side bolts were rubbing against the batteries, wearing into their walls, so added plastic spacers between the box walls and the batteries to prevent that.

With the new trailer, I thought about moving the batteries to a tray built on a reinforced rear bumper to reduce tongue weight like you. Electrically there wouldn't have been any problems, I think. The existing 6ga cable from the mid-trailer converter to the front junction box would feed the jack, stabilizers, and other (?) stuff.

But laziness got in the way, and now my Solar panel wiring is routed to a controller at the front near the batteries on the tongue. On the positive side, they say a high tongue weight makes for a more stable tow.;) But my truck doesn't particularly like it.:(

[mbopp]

The wiring should be OK as you described it. Be sure to isolate the old battery feed to prevent a short, and add a circuit breaker between the batteries and the converter.

[climb_on]

I'm particularly interested in thoughts about the wiring.

[climb_on]

RoyB wrote:
If you vent the batteries be sure it is a box that is vented not just a vent for the larger area where the batteries are sitting. All those fumes are very corrosive and will attack anything metal.

Also if you boil out the fluids you need to address where the run-off is collected or bypassed to.

The battery fumes are also very explosive and should not be around anything that can spark on you.

I personally would not like having wet cell batteries anywhere close to where I would be sleeping. To me batteries belong outside on the trailer tongue but you gotta do what you gotta do sometimes...

If money was no object here I might think about getting some sealed AGM type batteries if they were to be used inside the trailer.

Roy Ken

It's not ideal of course, but I feel it's reasonable and can be done safely. Good point about the metal corrosion in there. I only use SS fasteners in my RV, so I should be fine there. I will vent the new battery compartment space and mount the current battery boxes in that space. They will catch any boil over.

MM49 wrote:
I like your idea of moving batteries, but your plan will not work.You are loading a 150lbs on the heavy side of your trailer.
MM49

I'm not worried about 150 throwing off the side to side balance of an 8000lb trailer. I tend to think the slide out is the heavier side, not the side the batteries will be on.

[MM49]

climb.on wrote:
I am moving my pair of Costco Golf Cart Batteries from the tongue, to the rear of the camper under the bunk area. Primary reason is to get my tongue weight down a little bit. I've done all the calculations and scales visits and this is a good solution to keep me in the 900-1100 or 12%-14% tongue weight range.

So I would obviously need to put the batteries in a sealed, secured and vented battery box top and bottom - no problem. The new battery location would be located right next to the charger/converter, so wiring would be very convenient. This pic shows the new location.



Question: Is rewiring the batteries in a new location, as simple as I think it is? Battery negative bonded to the frame and Battery Positive to the 2nd lug of on the charger/converter circuit board (see picture)? I would also add a battery disconnect near the new battery location, like we have up front.



Also, there are electrical component wiring (emergency brake, tongue jack,etc) at the old location on the tongue that I think will still operate as long as I leave the existing positive battery cable in tact. I will leave all the existing wiring to the front, in tact anyway, as to easily return to the original setup if desired and to keep power to the front junction box. Is there something I am forgetting to consider here?

I like your idea of moving batteries, but your plan will not work.You are loading a 150lbs on the heavy side of your trailer.
MM49

[RoyB]

If you vent the batteries be sure it is a box that is vented not just a vent for the larger area where the batteries are sitting. All those fumes are very corrosive and will attack anything metal.

Also if you boil out the fluids you need to address where the run-off is collected or bypassed to.

The battery fumes are also very explosive and should not be around anything that can spark on you.

I personally would not like having wet cell batteries anywhere close to where I would be sleeping. To me batteries belong outside on the trailer tongue but you gotta do what you gotta do sometimes...

If money was no object here I might think about getting some sealed AGM type batteries if they were to be used inside the trailer.

Roy Ken