I haven’t measured it, but I’m guessing I get about 8 hours on a charge, maybe a little more. Found two things that improve battery life:
1) Rockbox. The clip+ release is still in beta; it’s buggy but quite usable, and the battery lasts a LONG time. I’m back to OF until the RB stable release is out – then it’s Hello Rockbox!
2) Custom EQ burns a lot more juice than Normal EQ. I don’t know about any of the presets – imho they’re all terrible, so I don’t use 'em. I set my EQ back to normal, and I’m getting better battery life.
Yes, I’m disappointed with the battery – Sansa advertises “up to 15 hours.” However – 8 hours will do, and the player is terrific.
I’m wondering about Replay Gain – it uses processing power, right? Has anyone noticed if the battery lasts longer if Replay Gain is off? I’ll turn it off (doesn’t work worth a hoot anyway), and if it makes a difference, I’ll post back.