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MacBook Pro Battery - When should I replace my battery.

I have had my MacBook Pro 15" for around 2 years now and I am finding the battery life to become limited and will only last around 45 minutes without being plugged into the mains. Is it my responsibility to replace this or are the batteries under any kind of warranty? What is the expected battery life with Macs anyway? Is it expected that you will just replace it after 2 years anyway?

Any help greatly received before I take the plunge any buy a new battery!

MacBook Pro, Mac OS X (10.4.11)

Posted on Nov 25, 2008 7:40 AM

Reply
22 replies

Nov 25, 2008 3:12 PM in response to ics2j2k

In general, a battery should still be at 80% of its capacity after 300 cycles. If you have fewer cycles than this and far less capacity, you may have a defective battery. However, if you have over 300 cycles, your battery may just be getting to the end of its useful life. Batteries do wear out over time. Apple would not be inclined to replace it under warranty unless it can be determined to be defective.

You can look up Battery information in the System Profiler. See what it says under "cycles" and "condition". That will tell the tale.

Post back if you have further questions.

Good luck!

Nov 27, 2008 2:02 PM in response to S.U.

SU, I tried the two links you posted in order. First of all, I've definitely tried restarting/force quitting things/shutting down, etc. The SMC process to me seemed a little risky for me to try since its basically resetting my Pro to factory standards... something I don't want to put my HD through, which has too much on it already. And I hardly think resetting will work since the problem with my Pro crashing is definitely not software related (it runs fine forever when hooked to the AC adapter). Secondly, I have already gotten the BatteryUpdate 1.2 in software update a while ago. I think I may just have to go to the Genius Bar and get a new battery 😟

Nov 27, 2008 3:25 PM in response to GunSlingerStyle

Probably so. I believe the SMC is an actual computer chip on the logic board, so resetting it should not affect your hard drive. It only resets that chip to factory standards.

It really sounds like you have a defective battery. Print out the article and take it with you, as not all Apple guys are familiar with it. If they don't want to replace the battery, ask to speak to the store manager, and if still no joy, call Apple and ask to speak to Apple Customer Relations. There have been a surprising number of people who have had trouble getting defective batteries replaced.

Good luck!

Dec 1, 2008 9:43 AM in response to ics2j2k

Check this out:

Read some of the article below and for the full article with tables etc, click on:

http://discussions.apple.com/post!reply.jspa?messageID=8520425

How to prolong lithium-based batteries (BU34)

Battery research is focusing heavily on lithium chemistries, so much so that one could presume that all portable devices will be powered with lithium-ion batteries in the future. In many ways, lithium-ion is superior to nickel and lead-based chemistries and the applications for lithium-ion batteries are growing as a result.

Lithium-ion has not yet fully matured and is being improved continuously. New metal and chemical combinations are being tried every six months to increase energy density and prolong service life. The improvements in longevity after each change will not be known for a few years.

A lithium-ion battery provides 300-500 discharge/charge cycles. The battery prefers a partial rather than a full discharge. Frequent full discharges should be avoided when possible. Instead, charge the battery more often or use a larger battery. There is no concern of memory when applying unscheduled charges.

Although lithium-ion is memory-free in terms of performance deterioration, batteries with fuel gauges exhibit what engineers refer to as "digital memory". Here is the reason: Short discharges with subsequent recharges do not provide the periodic calibration needed to synchronize the fuel gauge with the battery's state-of-charge. A deliberate full discharge and recharge every 30 charges corrects this problem. Letting the battery run down to the cut-off point in the equipment will do this. If ignored, the fuel gauge will become increasingly less accurate. (Read more in 'Choosing the right battery for portable computing', Part Two.)

Aging of lithium-ion is an issue that is often ignored. A lithium-ion battery in use typically lasts between 2-3 years. The capacity loss manifests itself in increased internal resistance caused by oxidation. Eventually, the cell resistance reaches a point where the pack can no longer deliver the stored energy although the battery may still have ample charge. For this reason, an aged battery can be kept longer in applications that draw low current as opposed to a function that demands heavy loads. Increasing internal resistance with cycle life and age is typical for cobalt-based lithium-ion, a system that is used for cell phones, cameras and laptops because of high energy density. The lower energy dense manganese-based lithium-ion, also known as spinel, maintains the internal resistance through its life but loses capacity due to chemical decompositions. Spinel is primarily used for power tools.

The speed by which lithium-ion ages is governed by temperature and state-of-charge. Figure 1 illustrates the capacity loss as a function of these two parameters.

Dec 3, 2008 1:16 PM in response to S.U.

I have a battery problem. The profiler says I have 675 mAh remining at full charge and 240 cycles. Called Apple and they confirmed it was defective but since it was a core 2 machine it would not be covered under a 2 year extended warrenty for batteries in the non-core 2 even though it is the same problem. They admitted it was defective but would not replace it. They were actually rude and didn't really seemed interested in discussions after they said it was my problem. Good consumer relations, they don't care.

Dec 3, 2008 4:43 PM in response to ics2j2k

My macbook pro is 2-3 years old. My battery takes a while to charge and then once charged will only last 40 minutes.
I looked at the power info and under health info, it only has 112 cycles, but under condition it says check battery. When I turn the computer over and push the battery button, all lights are illuminated. When I unplug the computer the computer indicates it only has 68 minutes of charge.
I reset the SMC, but that did not help.
Do I need to replace the battery?
Thanks to anyone with suggestions

MacBook Pro Battery - When should I replace my battery.

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