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I have a Macbook Pro whose battery has recently dropped from 3 hours of charge to 1 hour.

Is this the actual way for batteries to die? I thought that it will hold regularly less and less, but not have such a huge drop at once... Or maybe I've done something wrong with it?

The Mac profile utility says I have 130 Cycles left, and I've had this MacBookPro for at least 3 years. Is this the way it goes ?

Note: the profile also says "Check your battery". Is there a utility that has this check feature?

Added : A screenshot of the suggested Coconut check : What's your opinion ?

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1  
As for your profile utility says I have 130 Cycles left Does it actually say "left"? Or might it mean: used? (Mine says "Cycle count: 336; Condition: normal") And do you ever calibrate the chip on your battery? Maybe (but, I guess not, after 3 years) it's just thinking the battery life is that bad. –  Arjan Sep 4 '10 at 13:47
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3 years is actually quite good for a battery ... –  harrymc Sep 4 '10 at 16:57
    
Apple authorized service providers have utilities to check your battery. –  Daniel Beck Jan 26 '11 at 14:38
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4 Answers

up vote 4 down vote accepted

Laptop batteries can indeed die quickly like that.

Coconut battery is a free utility for Macs to check the health of your battery. I think that would be a place to start, but my feeling is you may be replacing the battery in the near future.

EDIT:

Based on your coconut screenshot, you battery is at less than 1/2 its original capacity. Since it looks like your mac is actually close to 4 yrs old, this is not unexpected. It also means you won't be under warranty if you want a new battery.

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"This is especially likely if you don't fully deplete the battery each cycle" Actually, with current LiIon batteries, the battery will live longer if it's not depleted fully on each cycle. –  sleske Sep 4 '10 at 13:48
    
From what I've read, on Li-Ion batteries, if charge goes below 20%, the wear on the battery increases considerably, so it's best not to deplete them. –  AndrejaKo Sep 4 '10 at 14:17
    
You guys are right. I edited the answer to reflect that. –  JNK Sep 4 '10 at 15:12
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If your MacBook Pro is still under warrantee (I've got a similar machine whose AppleCare just ran out this month) and the battery is defective, they'll just give you a new one. This happened to me a few months ago: I noticed considerably decreased battery life--the information shown to me in Coconut battery and by OS X pointed to a non-use-related issue--I took the machine to the Apple store, they booted it from a very particular hardware tester, and it told them "battery faulty, replacement approved." They then used a barcode scanned on the screen to pick up a replacement approval barcode displayed by the software; it was pretty neat.

So even if your situation won't match this one, we can still take from this story that there is a such thing as a faulty laptop battery. Get coconut battery like JNK suggested.

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I would suggest that you take it into an Apple retail store and make a Genius Bar appointment. They have a special EFI tool on a flash drive to boot your computer from that will show you more about the health of your battery. I don't think that the appointment should cost anything, even if you don't have Apple Care (but be sure to ask before signing any papers).

This happened to me after about 2 years of use and I think that it is just the expected lifetime of a battery.

For what it's worth, ~300 cycles is the mark at which Apple stops warranty-ing its batteries (or three years--the length of Apple Care.)

Also, here is Apple's recommendations on battery usage.

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Below is an excerpt from Apple's recommendations for their batteries. If it was me, then before replacing the battery I would try to completely discharge/recharge it for at least a few cycles to see if that helped.

Also, as suggested in another answer you should definitely go through the process to calibrate your battery if you have not (recently) done so.

Standard Maintenance For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month.

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