Battery Explodes

[Bernard Littau]

> >I think I'll go pry the tops off my maintenance free vented battery and
> >check the fluid level today.
>
> No, you shouldn't break the seals if it is a maintenance free battery.
>
> Maintenace free batteries are just that...maintenance free...and
> sealed except for a port to let off gas.  There should be an
> indicator on the top of the battery that shows electrolyte level and
> state of charge; some go clear when the fluid is too low for the
> battery to be safely used anymore.
>
> Maintenance free batteries aren't like the traditional battery with
> cell caps you can remove to fill up...they're designed to operate
> sealed.

I beg to differ.  At least on the prohibition on breaking the seals and that
"maintenance-free" batteries are indeed maintenance free.

The difference between a "maintenance-free" battery and a "normal" battery
is in inclusion of some catalytic fluff at the top of the cells, usually in
the caps.  This fluff is there to encourage H2 and O2 given off by
electrolysis to recombine into H2O, rather than be vented out, and fall back
into the cell where it belongs.  As long as the seal remains intact upon
replacement of the caps, there is no problem with checking the level and
density of the electrolyte in a "maintenance-free" battery.

I wonder if it was "maintenance-free" types of batteries that exploded.  If
they had had maintenance, they would not be low on fluid to the point of
building hydrogen (and oxygen) pockets and allowing arcing across the
plates.

Best,

Bernard Littau
Woodinville, WA
'88 5ktq