i did the same thing with my ds and the problem is the battery probably burned out so make sure ur ds is dry so wait about a week or two then look on ebay or call nintendo 1-800-255-3700 and ask for a nintendo ds or ds lite battery whichever u have im not sure how much it would be at nintendo but its like 5$ on ebay and make sure it looks like ur broken battery because some are different.
Brenden Reader, June 2009