A charging battery produces hydrogen, which is lighter than air, so it
dissipates quickly from a vented battery box.  Inside the battery it can
explode, usually when you start the car, or when you jump the battery
incorrectly.

Stuart

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
M'obeechi
Sent: Tuesday, June 03, 2008 2:44 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Optima Blue D31M

Okay, but the metal of the unit will still get hot, and if a highly
flammable gas were to encounter a heat source, isn't there the possibility
of combustion, especially if the flammable gas becomes concentrated in a
confined compartment?

From: Loren Busch <starwagen@GMAIL.COM>
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Optima Blue D31M

>  RE: The out-gassing possibility of the standard automotive battery,
coupled
> with use a propane heater like the Propex is enough to give me pause. Is
> this gas flammable?
>
> The Propex takes all combustion air from outside the vehicles and all
> exhaust goes outside the vehicle.  No interior air gets near the ignition
> source.  Interior air is only pulled through a heat exchager, total
> seperation from the ignition source.
>

----- End Original Message -----