I've honestly never had the problem.
Frankly, I use my ps3 quite often because I usually buy the multiplatform games for my ps3 instead of my 360 so it's my 360 that only gets used a few times a month--but I just use regular AA's for it.
My sixaxis probably gets around 20-25 hours of "on" time per charge (which is actually pretty good--lol, my wii mote only gets around 6-7 hours).
I wouldn't expect the dualshock to be any better though---I actually expect it to be a bit worse, but don't really know for sure.
I'll find out soon though! I just got my DS3 today!
PSN ID: Sorrow880
Gamertag: Sorrow80
Wii #: 8132 1076 3416 7450







