On 30 Mar 2007 at 12:28, scheefj at netscape.net
One of the reasons UPSs use sealed lead-acid batteries
is they are
located indoors. If you want to use marine or tractor (or regular car)
batteries, they should be located in the proverbial "well ventilated
space". Lead-acid batteries give off hydrogen and oxygen when charging,
a volatile mixture that will linger in any enclosure. I use
for replacement SLA batteries where a 4-battery
pack is $200.
Where the pack is kept on perennial "float", such as a UPS, emissions
are very low (as witnessed by the tablespoon or so of water I need to
add to each cell every 6 months) The small amount of hydrogen, being
much lighter than air, dissipates quickly. (That "lighter than air"
aspect is also one of the reasons that I refuse to run propane into
the kitchen, as it's heavier than air and will accumulate in low
I suspect one of those "emergency" lamps that are used in public
spaces that employ a motorcycle battery generate as much or more H2.
The oxygen I don't worry about. You'd probably generate more
hydrogen than the batteries do in a year by using a capful of Drano
to unclog a drain.
A little off-topic, but interesting nonetheless is how much hydrogen
is liberated by electrolysis. There were (and perhaps still are)
firms offering a "generate your own welding gas" rig by electrolyzing
water with potassium hydroxide added. A 240 volt, 20 amp rig
generated enough gas to power a very small jeweler's torch. And
there is very little caloric content in the flame--you could pass
your hand through it. I'll stick with acetylene, thank you.