[RE-wrenches] battery venting

[Jeff Yago]

Jay,

I have had a solar charged 12v RV/marine battery explode inside a very large
work trailer, but found that the battery was bone dry which may have been
the real reason for the melt down and not a trailer full of gas as the only
damage was a totally exploded battery case.  I was working inside a metal
shop building back in the 1970's operating a hand grinder about 30 feet away
from a battery fork truck on charge.  A tiny spark from this grinder was
enough to set off the gas that was venting from the industrial battery and
down through the cap, causing the entire top of the battery to blow off.
Loudest thing I ever heard and acid covered plastic all over the shop, but
no damage to anything else but the battery.

Since then I have been near other batteries that had the same type
"explosion" but in every case the damage was limited to my ears and the tops
of the batteries.

However, while at a Trace Engineering training class in Washington back in
the late 90's they showed us a video of a large metal building that housed a
very large industrial battery bank and the building was totally destroyed
from a battery gas explosion.  

As I recall, the building construction was lightweight frame and galv. sheet
metal.  This was a very large group of standby power batteries (maybe glass
cells?) and most likely had poor battery maintenance, but the building
construction was fairly open, lots of openings, so there must have been a
huge amount of venting gasses for a very long time or you would expect the
building to have more than enough fresh air ventilation to dilute the gas.
Maybe somebody has a copy of this video?

Jeff Yago
DTI Solar Inc.