This method works really well. Just use a good stainless rod to help conductivity.

Rust Removal Tip Video - Metacafe

For best results don't submerge you battery connectors. Use a peice of good wire and keep them out of the solution. You should see a decent amount of bubbles. If you don't check your connections.
When your done take the parts and power wash them to get the left over crap off them before painting or coating.

This is a pretty old hot rodders trick that works pretty well. Electrolysis (in case you didn't bother with the link)