Rut-ro Raggy! I will try another battery. But if that's not the case, what could the prblem be?
Not sure, loathe to say PSU issue, but if its comparing the battery voltage to a psu derived voltage then it could be psu or even mobo.
Before you try a new battery try resetting the bios, I doubt it, and make a note of the settings before you do, but its a possibility that it needs resetting to 'know' that it should treat the battery as new.