Evolution of Hydrogen Gas

["Steven Naugler" <snaugler earthlink net>]

David,
    I have questions about the Ford EV Ranger pickup you referenced in the
following text:

"Well, I agree, but with a caveat.  Most garages ARE leaky.  My tractor is
in my
insulated but leaky garage.  But I know people who have tested Ford Ranger
electric pickups; 24 (!) 8V batteries, in series.  They run a fan whenever
the
charger is operating, to carry away the Hydrogen.  After testing, they 
found
that
they had to run the fan for 30 seconds AFTER the charger went off; the
mixture
was still combustible!  Yet we allow the batteries to be charged in a 
normal
garage."

1.  Is the fan built into the truck?
2.  Or is it part of the garage where charging occurs?
3.  If it is part of the truck could it be that the 30 second delay between
end of charge and turning off of the blower is to account for the time
hydrogen bubbles rise out of the battery electrlyte? ( I know that after I
turn off my GE charger I hear a gradual reduction in the bubbling noises
coming from the batteries.)

Steve Naugler