Battery won't charge

I installed Windows 7 on a Toshiba Satellite M200, built for Vista, which had been running XP. No problems. When it came time to reformat and re-install I couldn't fine the 7 disk, so I used a different one. Soon after the battery lost most of its power, lasting only around 10-20 mins on full charge whereas previously, even with Windows 7, it got around 90 mins. Changing back to XP didn't help. I gather this is a common problem: http://www.taranfx.com/windows-7-kills-battery.

Anyway, after re-installing XP I bought a second-hand replacement battery. This one won't even charge beyond 3%, and the machine shuts down within seconds of AC being unplugged. Now I know it's probably not a good idea to buy second-hand batteries but this had a one month warranty and was half the cost of a new one. I am not sure, though, if it's a problem with the battery itself or something else.

The sticker on it is exactly the same as the original, except that it says it was made in Japan, whereas the original said Made in Korea, and the 'white' writing on the sticker is a bit darker than the original. I don't know whether that indicates it's a fake (I bought it in Thailand so it wouldn't surprise me). Unfortunately I am in a different country now so I can't take it back to the shop.

Another thread suggested calibration, but that isn't in the Power options.

Is there a way of ascertaining whether the problem is incompatibility, age, or something else?

Thanks.