Is there any way to check the life of the BIOS Battery on my desktop?
Nope. You can get information from your motherboard on power supply voltages, fan speeds and various temperatures, but battery information has never been included on any board I’ve seen.
Your BIOS battery is most likely a CR3032 style battery (just like in your watch). You could take that out and measure it with a voltmeter, but I don’t know what the results would tell you. If you’re worried about it, just replace it. They only cost a buck or two and last for years (I’ve messed with PCs since the 286 era, and I’ve only ever replaced one once).
Thanks Nanoda. My battery is a CR2032 according to my documentation. I ordered a Maxell battery from Battery Bob.