I am looking to upgrade my battery to two golf cart's. However, I can't handle the additional tongue weight, so I was considering relocating the batteries to either under my rear bunks or on the floor of the pantry. I understand that the batteries need to be vented so I was going to have the batteries located inside a sealed battery box vented to the outside. I know the vent needs to vent up due to the gases rising. My questions are do I need a lower intake vent to bring fresh air into the box and is it difficult to relocate the batteries. I have little experience with trailer modifications. Does any see any issues with relocating the batteries that I may be missing?

Greywolf26dbh wrote:I am looking to upgrade my battery to two golf cart's. However, I can't handle the additional tongue weight ... Really? You haven't said just which 12 volt battery you have but it likely weighs 50 to 60 lbs depending on which group size it is. A GC-2 6 volt typically weighs about 60 lbs so if you replace the single 12 volt with a pair of 6 volts you'd be adding about 60 lbs more to the trailer tongue, with perhaps 80% of that showing up as tongue weight because the batteries will actually be sitting aft of the coupler which is where tongue weight is measured. If increasing your trailer's gross tongue weight by a mere 50 lbs puts you well over whatever rating it is you're concerned about that suggests you have bigger issues that just gross tongue weight. Have you weighed your trailer fully loaded and ready to camp so you know where it's average GVW typically sits and in that state have you weighed the tongue so you likewise know for a fact what it's average gross tongue weight is? And yes, in case you're wondering I do know what I'm running with my own trailer as I long ago invested in a purpose designed Sherline tongue weight scale so I know for a fact just what percentage of gross tongue weight I'm typically running.

If it's in a sealed box with out going vent then you need a in coming vent. That said, rewiring to converter is required but not that difficult, also, power coming from TV for recharge can be affected due to longer distance. And make sure you have 12v supply to break away switch for TT brakes.

The MTS style of vented, hose, battery box have a bottom drain hole that provides for inlet air. Ours came that way from the factory in an enclosed compartment.

AGMs don't need to be vented. One of the benefits of paying a little more...

I'm probably one of a handful of guys that have done this, relocating LA batteries inside an RV. It's usually more than the average RV owner wants or needs to do. I did it for weight considerations. I built my own box but most guys would find it easier to buy an off-the-shelf dual battery box and install a vent. The vents to and from the box do not have to be that large. The amount of hydrogen gas displaced during charging is not a large amount. Yes, it's a good idea to have a lower mounted fresh air supply hole in the battery enclosure to provide gas flow to the outside. Hydrogen is much lighter than atmospheric air. If you're concerned about hydrogen flow back out of the air inlet (really shouldn't be a concern), install a flap on the inside of the battery box or put a small fan onto the air inlet.

Relocating battery | Good Sam Community

15 Replies

JWRoberts
Explorer
Feb 28, 2016
Ditto
icanon wrote:
If it's in a sealed box with out going vent then you need a in coming vent. That said, rewiring to converter is required but not that difficult, also, power coming from TV for recharge can be affected due to longer distance. And make sure you have 12v supply to break away switch for TT brakes.
4X4Dodger
Explorer II
Feb 28, 2016
I added two 20 liter gas cans (with gas) to my tongue and had no issues whatsoever. But I knew my tongue weight and how much I can add to it.

The addition of these batteries will in all likelihood not affect a thing unless you are pretty grossly over your tongue weight already.

The closer the batteries are to the vehicle will mean better charging from that source. But that is the only significant problem I can see with moving them.

Access is important. You dont want them where you cant get at them easily.
SoundGuy
Explorer
Feb 28, 2016
Greywolf26dbh wrote:
I am looking to upgrade my battery to two golf cart's. However, I can't handle the additional tongue weight ...

SoundGuy wrote:
Really?

If increasing your trailer's gross tongue weight by a mere 50 lbs puts you well over whatever rating it is you're concerned about that suggests you have bigger issues that just gross tongue weight.

JaxDad wrote:
Sounds like a project to make a very simple thing into a huge hassle to me too.

Exactly. It does sound though like the OP is nevertheless intent on going ahead with this even though it's questionable why adding a second battery to the trailer tongue would make enough of a difference to justify going to all this trouble moving both batteries to another entirely different location inside the trailer, with all the attendent issues that would have to be addressed. :h
JaxDad
Explorer III
Feb 28, 2016
SoundGuy wrote:
Greywolf26dbh wrote:
I am looking to upgrade my battery to two golf cart's. However, I can't handle the additional tongue weight ...

Really?

If increasing your trailer's gross tongue weight by a mere 50 lbs puts you well over whatever rating it is you're concerned about that suggests you have bigger issues that just gross tongue weight.

Sounds like a project to make a very simple thing into a huge hassle to me too.
icanon
Explorer
Feb 28, 2016
wanderingbob wrote:
KEEP IT SIMPLE . Fifty pounds will make very little difference . Put a couple cases of beer behind the axles and it will be OK!

As long he doesn't drink them.
wanderingbob
Explorer II
Feb 27, 2016
KEEP IT SIMPLE . Fifty pounds will make very little difference . Put a couple cases of beer behind the axles and it will be OK!
westend
Explorer
Feb 27, 2016
Greywolf26dbh wrote:
So are you saying the lower air intake vent is to the inside of the trailer or to the outside as the exhaust vent?
I have my intake on the inside of the trailer. You can draw air from anywhere as long as you aren't introducing any bad gases back in like exhaust gas from appliances. I located the intake on the opposite side of the battery box from the outflow.
AllegroD
Nomad
Feb 27, 2016
Place batts on tongue and move something else to the rear.
Happy_Prospecto
Explorer
Feb 27, 2016
Brian, if you stay with the lead/acid batteries, do a google search for battery box fans-- lots of good info out there to ventilate battery boxes.

The information is out there all you have to do is let in.
Greywolf26dbh
Explorer
Feb 27, 2016
So are you saying the lower air intake vent is to the inside of the trailer or to the outside as the exhaust vent?