Forum Discussion

bgrasspkr's avatar
bgrasspkr
Explorer
Jun 04, 2014

Question on battery gassing

Okay Folks, here is what I am up to. To start, I have a 2006 Outback 5th wheel, battery tray in the usual spot up front in the storage compartment. The plastic tray is recessed into a hole cut out in the sheet metal, battery sits in there, capped by a vent hose to the outside of rig. The tray is cheap ( of course) and has cracked a few inches on the upper lip where it sits in the cut-out. I took the tray out, as I could picture the battery eventually falling through and bouncing down the road behind me.

I have enough room in that area to put another battery ( group 27 ) right next to it, and wire them both up permanently, if I don't use the tray. So I put a piece of wood over the hole, set both batteries next to each other, and they hook up real nice. I then attached some small pieces of wood around the base so they don't move.

So a couple things. Not sure the wood base is such a good idea. I know battery trays are plastic for a reason. Probably resistant to battery acid. These are wet cells. So this will be temporary. More importantly. I now have no vent cover. So here are my questions.

1. Is it hydrogen gas that is produced by the battery.
2. Is the discharge highest during charging?
3. How concentrated can this get in the front basement of a 5th wheel trailer, ie enough to be dangerous?

So should I try to either design an enclosed area with a vent cover, or do they sell them in different sizes?

Thanks
LZ

10 Replies

  • wa8yxm's avatar
    wa8yxm
    Explorer III
    Jun 05, 2014
    bgrasspkr wrote:

    1. Is it hydrogen gas that is produced by the battery.
    2. Is the discharge highest during charging?
    3. How concentrated can this get in the front basement of a 5th wheel trailer, ie enough to be dangerous?

    So should I try to either design an enclosed area with a vent cover, or do they sell them in different sizes?


    1: Hydrogen, oxygen in the ideal ratio of 2h to 1o, plus a bit of sulfur just to make it nasty.

    2: During over charging, (Equalization) I believe its during charging in all cases though.

    3: Varies with the degree of overcharge, and how fast the charge is, If you charge too fast it can get quite heavy.

    When I stored batteries in the house I always set them on scrap wood, Now,, there are myths about "You should never set a lead acid battery on this or that kind of floor due to this or that mythical reason. But I ignore those,, I set it on wood, scrap wood at that, because if any acid got on the outside of the battery scrap wood was real easy to replace,, Unlike the floor below it, and by the time it ate through all that wood, not much acid (or for that matter any acid) left. And the floor was thus undamaged.

    Should you try to design an enclosed box? I would build your wooden box as tightly as possible and then use a good sealing paint inside and out, You can use a good grade of sealant (GOOP?) on the joints to seal them, weather stripping is also good, Weatherstrip the lid and vent it like the original box, also provide a drain (PVC works well here) so you can easily rinse the box out.

    And if you have room for two grop 27s You might see if you have room for a pair of GC-2,, Two 27s is just under 200 amp hours at the c/20 rate, two GC=s 220-230. More power as Tim Allen might say.
  • RoyB's avatar
    RoyB
    Explorer II
    Jun 05, 2014
    We cringe every time we go to bed in our 5th wheel with the propane tanks bombs and two batteries all situated in their separate storage compartments just under our bed. They are vented to the outside of course but still remain under us while we sleep.

    I always thought this wooden box design was neat this guy did with his 5th wheel for installing 4EA 6VDC GC2 type golf cart batteries. This is across the front access door.



    Photos from GOOGLE images

    Roy Ken
  • 2oldman's avatar
    2oldman
    Explorer II
    Jun 05, 2014
    bgrasspkr wrote:
    anybody blow up there trailer with Hydrogen??
    In all the years I've been here, I've never seen it. But then we're all pretty safe.. wink wink.
  • mena661's avatar
    mena661
    Explorer
    Jun 05, 2014
    I did the same as BFL when I had my 5er. My front compartment wasn't sealed though. There was ventilation from where the front jack assemblies came into the compartment. Had no issues either.

  • bgrasspkr's avatar
    bgrasspkr
    Explorer
    Jun 05, 2014
    BFL, what a set up!! You know I don't think I am going to worry about it either. I am only charging on site with the darn cargo door open the whole week anyway, gas can't build up at all. Unless of course someone posts something to make me think twice. I've gotten in trouble more than once in my life thinking I knew better! Anybody blow up there trailer with Hydrogen??
  • BFL13's avatar
    BFL13
    Explorer II
    Jun 05, 2014
    I have been getting away with this for years now with the 5er, no problems noticed. (yet?) Six batts up front (two not showing off to the right), no vented trays.

    I do have the door up when charging from solar or from the generator and using the chargers (don't use converter for that) Gassing is strongest when near the end of the recharge after batts reach 14+ volts.

    On shore power, 12v on converter, batts charged and floating, no gassing really, but any there is gets a way out using that cable hatch I put in the door, plus the side doors to the cargo bay aren't that tight.

    I have the inverter etc in the same area and they have not been eaten by fumes either. Have not blown up the trailer from sparks.

    Can't say it is safe and everyone should do this of course, but so far so good here!

  • bgrasspkr's avatar
    bgrasspkr
    Explorer
    Jun 04, 2014
    2oldman, thanks for the link. Yeah, spending more money does solve a lot of problems,but I'd rather put the money towards a solar panel or genny this year.
  • 2oldman's avatar
    2oldman
    Explorer II
    Jun 04, 2014
    bgrasspkr wrote:
    1. Is it hydrogen gas that is produced by the battery.
    2. Is the discharge highest during charging?
    3. How concentrated can this get in the front basement of a 5th wheel trailer, ie enough to be dangerous?
    o should I try to either design an enclosed area with a vent cover, or do they sell them in different sizes?
    Yes. yes. I don't know. Check this out:
    battery faq page

    You can solve a lot of problems by switching to AGM batteries.
  • bgrasspkr's avatar
    bgrasspkr
    Explorer
    Jun 04, 2014
    Ranger, two batteries each in a new box with vent won't fit in the area I have.
  • Ranger_Smith's avatar
    Ranger_Smith
    Explorer
    Jun 04, 2014
    They sell the battery boxes with a vent and hose to go to a grille that goes to the outside. I put one of them in when I added a battery to my Montana 5th wheel I had

About Technical Issues

Having RV issues? Connect with others who have been in your shoes.24,322 PostsLatest Activity: Oct 02, 2025