What happens to a battery (nimh or nicd) if you reversed the leads(-to+, instead of -to-, +to+) Does it discharge it, or does it fry it or something in between? Thanks.
-Sam

In between what? You didn't say what you're connecting to the battery. A Triton, for example, will detect the reverse polarity and no harm will be done.

MM the charger

To answer it would be worse than if you shorted out the battery by the amount of current the charger is capable of. Smokin!

Lets say it was done on a trickle charger with no reverse protection.
-Sam

short circuit with the same amount of current added... ie as above

The world would slow down, stop, then start turning the other direction.