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I know you guys know this already, but these gell cells lead acids
will offgas severely when charging, discharging , sitting still, or
whenever they feel like it. I did discover one really nasty mode of
offgass that we can easily prevent. 

     Bottom line, let the batteries sit for minumum ten minutes, and
more like an hour before sealing the scooter or light - don't seal
unless ready to dive.

     Here is what I did. I was testing different batteries last night,
and I came across two seemingly identical batteries which had a volt
difference in voltage with a trickle charge attached. I threw a
non-automatic charge on the low battery, and imersed it in water, now
being suspicious of both batteries - it was bubbing hydrogen from the
relief plate. 

     I took it off charge, and it continued to do this for ten minutes.
I put a load on it and it stopped. I then tested both batteries, and the
one which had had the highest charge failed 30 minutes short of where it
should have burned, and the other ( the offgasser) was fine.

     I tried the offgass thing a few times - it takes several minutes
for it to calm back down after you apply a higher voltage to it than its
fully charged state. The correct fully charged state for these twelve
volters appears to be 13.33 volt. The other was at almost 15 - no good,
and higher than 13.33 applied to the fully charged battery produced gas.

     Closing up a battery like this turns your scooter into a bomb if
the hydrogen gets into the motor compartment. Let them rest open for a
while , and do not ever leave them closed until ready to go in the
water. Most of these chargers are not exactly precise instruments, and
you want to be carefull with this. Also, the batteries can do this
without being overcharged.

     Be carefull with these things - when they explode it is extremely
powerful. - G
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