If you haven't already, you might want to neutralize the acid with some vinegar. Otherwise it will keep eating at the board. Here is a link to one of Omegaman's repair threads. He does some nice work.
Vinegar is an acid in it's own right and will corrode copper. Rinse copiously with distilled water afterwards to ensure complete neutralization. Also, if you're cleaning up an alkaline battery a diluted acid like vinegar is fine, but for any other type (like lead-acid) you may wish to use a low pH solution like baking soda and water.