If "excessive" current is applied to a lead acid battery, the
electrolyte (sulfuric acid) will bubble. What's actually occurring is
that the extra electricity is splitting the water portion of the acid
into hydrogen and oxygen. Since most batteries are "sealed" it isn't
easy to add water back to replace that which has been split (and the
vapor vented.) Hence, you can consider this "harmful" to the battery.

If enough of the water is converted to vapor (and hence lost) the
lead plates are exposed. Lead can oxidize pretty easily, and lead
oxide can act as an insulator, reducing the capacity and
effectiveness of the battery.

On Apr 28, 2007, at 7:07 PM, PB wrote:

> Matt,
> Thanks very much for instructions that even I can understand!  I'm
> charging
> the battery on 2 amps now and will let you know how the test goes.
> (I'm
> using 2 amps because somehow I think that 6 amps would be harmful.
> Is that
> right, or can I use 6 amps?)
> Patti