RB wont start, and neither does normal mode

[DeAvalon]

this is pretty confusing. I had used rockbox for a while and it worked fine. Now, my ipod video (30g) is getting old and the battery lifespan is decreasing. It went out of batteries. I had a wall charger and and charged it for 24h.

After charging, it says:

Rockbox boot loader
Version:2.0
IPOD version: 0xFFFFFFFF
TOSHIBA MK3008GAL
Partition 1: 0x0B 28521 MB
Loading Rockbox...
Error!
Can't load rockbox.ipod
File not found
Hold MENU+SELECT to reboot
then SELECT+PLAY for disc mode

When i reboot it with menu+select, this screen appears

Please Wait.
Very Low Battery.

After a while (if charging) the RB error screen shows up again

Can someone help me? Can I either fix RB or Delete it and go back to the original mode?

[Chronon]

The message that you mentioned (Please Wait. Very Low Battery) is from Apple's code, not Rockbox.  (If you google for that message you will find many discussions about non-modded iPods that display that very message.)  If you would like to uninstall Rockbox you can find instructions for this in the manual.  However, I wouldn't blame Rockbox for what appears to be a dying battery.