Ammo Can for Gas Tank and Battery- Bad Idea?

Discussion in 'Motorized Bicycle Welding, Fabrication and Paintin' started by BrandonG, Apr 27, 2014.

  1. BrandonG

    BrandonG New Member

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    If I put a plastic mower gas tank and a SLA for lights in one ammo can, is it likely to catch on fire? I know the tanks vent gas, especially in the Florida sun. Fumes contained in a small space with a spark from the battery scares me. Do yall think this is a bad idea or will I be ok?

    Background:
    Im currently moving over to a full suspension 95 Specialized Stumpjumper FSR. On my old bike, I used an old mower gas tank after the stock one started leaking from the studs. I had the tank and a 12v 12ah SLA for my LEDs, a 55W light, and a car horn. I switched to a seatpost rack and reinforced it but the tank wont fit on this rack as easy since there is less clearance between the seat ad rack. An ammo can would allow for a larger and taller tank (currently have a 1/2 gal) and would be my battery box, and maybe extra room for whatever else I want.

    Attached is a pic of my old bike. The battery is in the cloth case (for water resistance) and sitting on plywood connected to the rack. There is also my stumpjumper with reinforced rack. I sat on it and it held my 185lbs! (The suspension is bottomed out so I could see clearances of the rack)
     

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  2. 2door

    2door Moderator
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    DON'T DO IT! I can't stress enough the danger of having a battery and a fuel container in the same closed compartment. Yes, the tank will vent and the fumes can/will collect inside the ammo box. What if a battery connection came loose while you're riding and the connection arcs. The effect will be exactly like what happens in the combustion chamber of your engine. The spark plug, or the bad connection on your battery will provide the ignition for an explosion.
    I wouldn't want to be straddling a box of gasoline fumes when that happens. Would you?

    Tom
     
  3. BrandonG

    BrandonG New Member

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    Thats kinda what I was thinking. Ill stick with what I had and just move it over.

    Thanks Tom!
     
  4. sub66

    sub66 New Member

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    if u had a sealed tank w external overflow done correct. maybe a ammo vent hole since its sealed. then maybe yes. but whatever man :) fumes are only ignitable in certain conditions. oxygenated ones.

    good luck w the ride
     
  5. 16v4nrbrgr

    16v4nrbrgr New Member

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    I concur, just vent the tank outside, make the electrical connections perfect and there's not much to worry about. I'd put a vent hole in the ammo can just in case it does burn, so it won't explode, since ammo cans are sealed for moisture protection for bullets.
     
  6. 2door

    2door Moderator
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    You need to do what feels right to you. Nevertheless putting blind faith in a vent or holes in the box just seems a little too 'iffy' for me. I did a stint as an aviation accident investigator and saw the results of a couple of events caused exactly by what you are wanting to do. That being, placing a fuel and a source of ignition in a closed container together.

    But, I won't preach and will step aside. Good luck.

    Tom
     
  7. CTripps

    CTripps Active Member

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    I wouldn't put them in the same space, even with an external vent hose. If you ask for trouble it will (eventually) find you.

    Can you go with separate cans? Maybe one (electrical) above the other, or maybe make a false bottom to make a space for the battery in a 'cargo' can on the opposite side?
     
  8. TakeiT

    TakeiT New Member

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    Also keep in mind that a battery can give off Hydrogen, so that should be vented too!
     
  9. CTripps

    CTripps Active Member

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    True, if you use a conventional (vented) lead-acid battery they can add thier own mix of a little hrdogen and oxygen to the equation; use a sealed battery if you can.. you also don't have to worry about where or rather which way up a sealed battery is. Downside is that if you overcharge a sealed unit it'll swell and distort, occaisionally to the point of splitting apart or cracking it's case. I've seen too many that that has happened to returned to the battery warehouse I used to work at... (Some idiot designed the Mazda Miata to use the SLA version of a riding mower (or U1 group) battery.. They're good for maybe 2-3 months installed, so owners and dealers would charge the %*!# out of them hoping to make them last a full spring-fall driving season then return them to us looking like mis-shapen footballs for warranty replacement).
     
  10. mapbike

    mapbike Active Member

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    I agree with those who warn against putting potential spark and gas fumes in the same place, why take the risk and gamble with getting deep fried from the backside up?

    If the two components can be totally isolated from one another in separate sealed containers inside another single container that has proper ventilation then I would think it should be safe.

    We risk bumps, scrapes and breaks every time we go zipping down the road on our motorized bikes as they are, no need to add another element of danger to the machine if at all possible.

    I'll take a bump, scrape or break any day over getting set on fire......!

    Map
    .wee.
     

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