The following report compares gadgets using the SERCount Rating (base on the result count from the search engine). Note: due to some search engine quota, not all result is available yet.
The only battery-operated multi-CD player that I've found
Rating: 5/5
This is the only multi-CD player I've found that runs on batteries. I've been using it for at least 2 hours every day at a swimming pool (hence the requirement for batteries) for several months, in general changing the CD for each song. The batteries last 7 hours.