Not long after his interview with Gamespot which indicated that the battery life on the PSP 3000 would be less than the current PSP, John Koller, a director at Sony has made a new statement:
"Hi, everyone, there have been reports about the battery life of the new PSP system (PSP-3000) being shorter than the current model (PSP-2000), following an interview we recently did with Gamespot. I’d like to make a correction and clarify that the new PSP will have equivalent battery life to the current PSP, about 4 to 6 hours for games and about 4 to 5 hours for UMD videos. While the enhanced screen of the new PSP draws a little more power, our engineers in Japan worked to reduce the power consumption of the overall system including its components, so you won’t have to worry about losing any time when enjoying the more vibrant visuals displayed with the new PSP.
We hope this clears everything up, and we’re certainly excited about letting you all get your hands on the new PSP and checking out the enhanced screen when it hits retail next month." - John Koller
Great news and this makes the PSP-3000 even more desirable - I know I want to buy it!
Source 
09-03-2008
