Audiovox D1420 4.2-Inch Portable DVD Player with Built In Rechargeable Battery
just follow the advice....
Following the advice of other reviewers, I played a full length DVD on AC power before charging and I've had no problems with the battery.  Small, compact and gets the job done!  The 'open' button (to remove a DVD) seems like it doesn't latch properly, but it's never popped open while playing so I guess it's OK.