Hey itsmoked,
The problem was, the cd player has a built is charger in it wo when the adapter is plugger in, the batteries charge, however, the user made a mistake of putting non-rechargable batteries in while charging and after that the battery life was drastically redeced. As it is relatively inexpensive to replace, to know why the batteries don't last long anymore will be simply out of curiousity.
Cheers