Is this a decent battery? How can I test it? *PIC*

[james2008]

I just bought a used Thinkpad battery for about $30.

What's a good way to test the actual battery capacity? (IE what power management settings should I use?) And is there a way to test the battery's "reliability" ?

Here are the stats from the IBM configuration program:



How's it look? Not good to me, @ 200+ cycles, <40Wh, and a manufacture and first use date 3 years past. Would you use this battery as an emergency backup during exams?

Moderator note: Please add "*PIC* (or such) when including an inline image. Props for keeping the size < 50KB !

[rkawakami]

"Actual capacity" is given as the "Full charge capacity". If you want to know what that means in terms of actual time before it goes flat, then you'd have to use the system in a "normal" manner along with a stopwatch. At the moment, the battery has about 75% of the design capacity, which if your system usually ran for four hours with a brand new battery, it will now only run for three.

As far as reliability is concerned, I'm assuming you mean how fast it's going to degrade until it no longer keeps a charge. For that answer, it depends upon may factors; how many more discharge-charge cycles it's put through, how deep those discharges are, the temperature the battery is subjected to, etc., etc. Could be a couple of months or it might last you another two years.

[james2008]

Sorry about the post title, forgot about that.

I don't intend to use the battery much at all - it's primarily going to be used as a back up in case of a power outage while I'm working.

Would you say it's a decent buy that should serve that purpose? Or would you look for a different/newer battery, given the info?

75% of the design capacity doesn't sound bad, but I read on the forum that you shouldn't buy a used battery with less than 40Wh remaining. And 200 charge cycles sounds kind of on the high side, and three years sounds kind of old.

But what do I know? This is the first laptop battery I've used.

[Temetka]

If you don't plan on using it all that much then don't sweat it.

$30 isn't a lot of money for a battery and yours still holds a 75% charge, not too shabby for that price. I wouldn't spend anymore cash on a better battery unless you plan to use it on battery.