The Setup:
The PSP reports 51% battery charge out of the box. The unit is used
(to play assorted games and videos) until it shuts down due to low
battery. It is then recharged to 100%.
Ridge Racers is inserted, and the AC Adaptor is unplugged. The PSP is
powered on and as the Ridge Racers logo appears, the clock is
started. The game is played continuously, with minimal time spent in
any menus and absolutely no replays watched.
The PSP is set to 75% max volume and brightness 3 (the highest
possible when using the battery).
Results:
At 3:45 - 3:48 (that's three hours and forty-five minutes) the POWER
light begins flashing slowly. Note that the light stays green, it
doesn't change color a la Nintendo's handhelds when the battery is
low--it flashes instead.
At 4:03:30, just over four hours, the game is interrupted by a
flashing low battery indicator, and the unit powers down.