Clip plus vs. 3xAA alkaline batteries (aka 4.5V)

[newClipUser]

Hello,
I just want to share my experience with people interested in hardware mod the sansa clip plus. I use my Clip+ for longterm ambient and nature sound recording. After some experiments with 3 AA NiMH rechargeable batteries replacing the lithium-ion pack I just tried  3 AA batteries, hopping the higher voltage of 4.5V would not burn the ICs(could be a bit higher with brand new batteries, I didn't even bother to use the multimeter to check)... I it worked out pretty well: I didn't feel any signs of overheating, no burn smells, and rockbox seems to run fine. I put the rockbox voice recording on mp3 recording and checked after 12 hours, and it still runs fine (didn't check the recordings though, but I suppose they will be fine as long as rockbox is still running and the recording clock is still counting).
I guess the batteries will run for more than 2 days, I even hope for 3 to 4 days non stop recording. But we will see.
People on the irc-channel told me that the shutdown voltage of rockbox is set at 3.3V, so the batteries will be almost used up at this point. Not too much energy wasted (correct me if I'm wrong).

[saratoga]

People on the irc-channel told me that the shutdown voltage of rockbox is set at 3.3V, so the batteries will be almost used up at this point. Not too much energy wasted (correct me if I'm wrong).

Thats pretty much exactly right for Nimh.

[newClipUser]

Ok, update: powered by 3 AA alkaline batteries the clip+ ran for a little bit more then 100 hours straight recording mp3 with 128bit quality. I wonder how much longer it would be able to record when the shut down voltage is lowered to 3,0V...

@saratoga
I was referring to nonrechargeable LR6 (AA) alkaline batteries.