Wayne...presume you're talking about an IBM ThinkPad R500 laptop. the reason they say you should have a working battery is that if your laptop dies while the bios is being updated, it is toast / cactus / a brick. This is because the entire bios needs to be updated to function properly, if only half the bios is loaded then the bios won't function and won't be able to fully update itself.You CAN take a chance and update it with only the mains power (unless the software won't actually let you), but if you get a power fail or even a glitch when it's doing it, goodbye laptop. You could splash out $30-50 for a new battery, but I seem to remember the R500 is fairly old, is it worth it? I don't know any easy way of fooling the laptop into thinking it has a good battery....
