[ghporter]

I have noticed that my MBP's battery doesn't seem to last very long lately, so I ran it down to about 20% before recharging it. Now iStat says it's "health" is at 45%, and System Profiler says its full charge capacity is 2332 mAh, and it's status is "check battery." It has 64 cycles, which is troubling to me-that's way too few for the battery to be this low at full charge, but I can't find a listing of the original capacity of the battery. Can someone help me out on this?

[mduell]

2.332 Ah / 45% = 5.2Ah
Or another way: 56Wh / 10.8V = 5.2Ah

Cycles didn't kill your battery, age and storage probably did.

[ghporter]

I didn't think the conversion was that straightforward. It's obviously below "50% capacity with 300 cycles," so I'm going to have to look into getting Apple to replace it-or biting the bullet and coughing up $130 for a new one.

I haven't stressed this battery, but I haven't babied it either. I only started plugging it in whenever I could recently because it just doesn't last..

[mduell]

Battery is only warrantied for a year, AppleCare does not extend it.

[Eriamjh]

Original MBP batts were about 5300mAh.
After 116 cycles, mine has 4785mAh of total like.

Meh.

[ghporter]

Well my MBP is now a "project." I need to get a new battery, and the 100GB drive is woefully small nowadays. I don't think I'll bother trying to upgrade the AirPort card in it-unless I can get the A/B/G/N card for later MBPs for less than $40..., but I think I'll be spending a weekend replacing the hard drive sometime soon. And the battery is still stocked at my local Apple Store, so it's just a matter of putting the money together.

[Simon]

Actually new 15" MBP (pre-unibody) batteries have a full charge capacity anywhere between 5500 and 5600 mAh. IOW per Apple's guidelines you should see no less than 4400 mAh during the first 300 cycles. If that happens within the first year of ownership you'll easily get Apple to replace the battery for free. If it's several months more than that you could be lucky if you ask nicely. However, if it's after two or three years even AppleCare won't help (batteries are exempt).

If the capacity drop happens after a year but before you've reached 300 cycles, what you're seeing is the effect of age. Li polymer batteries deteriorate with time, especially if they are stored in a warm/hot place (like a running MBP). That's unfortunately just part of life and the kind of battery wear you'll have to pay for yourself.

[ghporter]

Interestingly, after a drain and recharge yesterday, and sitting all night, my battery now shows 85% health with a max charge capacity of 4669 mAh... Oh, the power of cycling the battery!

I'm still going to get a new battery, but it's not as much a rush as it seemed yesterday.