Mitch wrote:
Are you by chance not connecting the charger directly to the battery
terminals


I'm connecting the + to the battery's positive, and the - to a bolt
head on the engine block.


That may be part of your problem. Connect the negative clamp from the
charger DIRECTLY to the
battery negative post.v Same thing with the battery positive post and
the charger positive clamp.
Get the cables out of there. Get the cables off both the negative and
positive posts and clean both posts THOROUGHLY before charging.

While its charging, clean the insides of the cables thoroughly.


Unless its totally dry (possible, but not likel) or unless the nternal
battery connections are broken, it should show continuity though the
battery, and ake a partial charge

Some "sealed" batteries can be refilled with electrolyte / distilled
water. Some are not as "sealed" as you miht believe.

If an internal battery connection is broken, you have a boat anchor. A
broken internal connection can't be "cured".

Have you used a good DVM to test internal continuity within the battery
to see if there is a boken internal connection?



I'll try cleaning again.