FLAC and battery life

On Rockbox forum I read that battery life in original firmware is very short when playing back FLAC files. Is it true? Do I have to install Rockbox on a new player to get 14-15 hours of FLAC playback?

Yes.

How come? And why does the battery suddenly improve when installing Rockbox? Can i go back to the original firmware if i regret installing Rockbox?

So i can’t play DRM files even if Rockbox and bootloader is uninstalled and flashed with the Sandisk original firmware?

@djchristian wrote:

So i can’t play DRM files even if Rockbox and bootloader is uninstalled and flashed with the Sandisk original firmware?

You might be able to, or you might not be able to. There have been reports going both ways, I believe.

I think you can but you might have delete and re add any DRM tracks. Search I know its been posted here or elsewhere before.

I can’t really remember the details, but IIRC the problem is that if you change the time in rockbox all the DRM tracks in the OF expire, so you have to readd them at the new time (or just don’t change the time).