It is to cry. Drastic and sudden drop in my notebook's battery performance

I’ve had this computer since the New Year, and when I first got it, a single charge would last about four hours. I looked down my nose at all the poor schlubs who, when entering a library or coffeeshop, had to duckwalk their way in, looking for a seat near an electrical outlet. But not me. I could depend on my battery for several hours if need be, even if it wasn’t topped up.

That was then.

Now I’m lucky to get forty-five minutes of use out of a battery charge. And I do know that they deteriorate over time, as this one was doing until about a week ago. I noticed that it was more like a couple of hours. But now it is so moribund that now, with a nearly full charge when I booted up just now, the life indicator says I have eighteen minutes left. I think it’s actually going to be less than that.

Is there any way to find out if one or more cells in the battery isn’t charging at all? Is there any way to restore battery performance?

If it’s a Mac, go to the Apple menu, select “About this Mac”, and then “More Info.” The “Power” section of the resulting system info gives you information like how many cycles are on the battery, it’s current condition (which will tell you if all the cells are charging), and it’s current and peak charge levels. If the machine is less than a year old, Apple will likely replace the battery for you on the spot at any Apple store.

For another brand, I’d send it in: a year is WAY too short for a battery to be failing so dramatically. It might be the circuitry that charges the battery, too – not the battery itself.

Are there any good analysis tools out there that I could download?