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evy's avatar
evy
Explorer
Jun 17, 2016

Building a battery box, info needed please.

Hi everyone,

I'm working on my very first DIY camper conversion, using a 2010 extended Ford E250.

Right now I'm planning my battery box for my two GC2 6V 215AH wet cells batteries.

I was planning :
-using plywood and caulking to seal it
-leaving 1/2" around the batteries and the box
-sealing the cover with a gasket and continuous piano hinges
-venting the box with a standard flexible pipe, 1-1/2" or 2" in diam. exhaust
-drilling many 1/2" holes on the floor between the batteries for air inlet (adding a screen mesh under the floor)
-adding a rubber mat underneath the batteries, do I need a pan?
-1/2" x 1/2" spacer all round the batteries on the floor to prevent them from moving around

If you have any issues or recommendations please don't hesitate, thanks!

10 Replies

  • myredracer's avatar
    myredracer
    Explorer II
    Feb 27, 2017
    There is at least one brand of exterior vent intended for battery venting. I installed one on a previous TT. It has a mating piece on the inside for connecting a standard 1-3/4" battery vent hose. Not sure what brand(s) these are - Valterra, MTS products, JR Products, etc. I bought our vent & hose at a local RV dealer. The one in this photo is on ebay:

  • evy's avatar
    evy
    Explorer
    Feb 27, 2017
    DrewE wrote:
    #1 looks more rain resistant to me, though it may be a matter of the angle of the picture. I would likely choose it for that reason and drill a little weep hole at the very bottom of the vent so any water that gets in has a place to drip out.


    That's a great idea, I will put a couple of holes on that bottom row.
  • DrewE's avatar
    DrewE
    Explorer II
    Feb 27, 2017
    #1 looks more rain resistant to me, though it may be a matter of the angle of the picture. I would likely choose it for that reason and drill a little weep hole at the very bottom of the vent so any water that gets in has a place to drip out.
  • evy's avatar
    evy
    Explorer
    Feb 27, 2017
    I will run a 2" dia flexible duct from the top side of the box to the outside (16" horizontal run)
    I will also make a 2" dia inlet vent on the bottom of the box.

    What type of vent should I install on the sidewall of the camper?

    I looked at what is being sold as a "battery box vent" and I have found 2 models that look a lot like them, which one would you suggest?
    I was thinking of putting a small slope towards the outside vent so if water comes in while driving it will drip out when stopped.



  • myredracer's avatar
    myredracer
    Explorer II
    Jun 18, 2016
    corvettekent wrote:
    I read some place that you should have 6" above the batteries inside the box. I don't know that you need that much space but leave enough space incase your next batteries are taller.


    Don't know about that, but I have read that the exterior vent should be min. 6" above the top of the batteries.

    The MTS Products sealed and vented battery boxes below have a 1 1/2" dia. hose (approx.) and same size inlet on the bottom. These particular boxes are commonly used in FW trailers. Funny thing is, with the battery sitting on the floor of the box, it blocks the inlet. When I installed one of these boxes in a previous TT, I raised the battery on spacers. I came across a bunch of used like new MTS boxes at the back of an RV dealer's parts store for $5 each so I bought a couple for a future battery project.

  • corvettekent's avatar
    corvettekent
    Explorer
    Jun 18, 2016
    I read some place that you should have 6" above the batteries inside the box. I don't know that you need that much space but leave enough space incase your next batteries are taller.
  • BoonHauler's avatar
    BoonHauler
    Explorer
    Jun 18, 2016
    The batteries can't be allowed to rub up against each other. You'll need a spacer between the two of them and the spacer will need to provide means of ventilation if in fact you're still planning on ventilating between the two.

    Personally, I'd want them held down as well.
  • westend's avatar
    westend
    Explorer
    Jun 18, 2016
    I made one for 2 X 6 V's that sits inside my TT. Basically, a plywood box lined with FRP, a weatherstrip gasket on the top, and a 3/4" reinforced tube for vent. All is well sealed with caulk and painted.



    Even managed to keep the cowboy theme:


    Edit: BTW, I did some researching on the volumes of gas that are created during charging. There is basically very little hydrogen produced and since it is much lighter than the atmosphere, moves quickly to the top of any containment. Your 2" vent will be more than adequate. You won't need too many or large holes to introduce the makeup air to the box. The hydrogen will vent and drag in available air through a very small hole. I used a 1/4" hole toward the bottom, opposite of the exhaust.
  • MEXICOWANDERER's avatar
    MEXICOWANDERER
    Explorer
    Jun 17, 2016
    Battery acid decomposes wood like a wolf eats mice.

    Go to Home Depot

    Go to the paint department

    Look for aerosol (spray) bed liner. RustOleum makes a good line.

    Follow directions. Three coats. This means under the battery mat too.
  • mobilefleet's avatar
    mobilefleet
    Explorer
    Jun 17, 2016
    I'd make the batteries more accessible with a slide out tray instead of fixed. Ball bearing slides with enough length of battery cable to adjust for when they are in the out position.

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