MacBook Pro battery question

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Computer question here -- I've done my research through other forums, but curious if anyone here has had any real experience...

My wife's 5 year old MacBook Pro was recently running pathetically slow. After a bunch of troubleshooting, she realized that the battery had swollen and puffed up, and was *very* hot. She removed and replaced the battery with an older one we had, this fixed all of the problems and the computer runs normally now. The battery was bought new from Apple just over 2 years ago.

Researching this online, it seems like people get unhelpful answers from Apple, including "it's supposed to do this" and "if your battery is old, your computer is old, buy a new one" and "it's not a safety hazard." I think all of that is ridiculous, since every other laptop battery I've ever replaced simply stops holding a charge instead of bulging and heating up.

It'll be a few days before I can get this into an Apple store (I'm not paying $20 for phone support). Has anyone here had a similar problem/experience?

Thanks!

[pgym]

Lithium ion battery bloat is a fact of chemistry. See also Lithium-Ion Batteries Hazard and Use Assessment, particularly "Cell and Battery Failure Modes - Non-Energetic Failures on p, 62.

An increase of internal pressure within prismatic or pouch cells will cause swelling.
Swelling can be caused by a variety of non-ideal chemical reactions including: overcharge, elevated temperature aging, and moisture intrusion.
Cell swelling can ameliorate some failure modes making it less likely that a cell enters thermal runaway, but it can also result in enhanced cell leakage rates.
Swelling commonly results in damage to battery pack enclosures.

I've experienced battery bloat in laptop batteries, cell phone batteries, camcorder batteries, and rechargeable batteries.

Macbook Pro batteries have a life expectancy of around 1000 discharge cycles, but there are lots of things that can reduce battery life: overcharging or over discharging the battery reduces battery life expectancy; charging at too low or too high voltage reduces battery life expectancy; thermal abuse (overheating), such as can happen when running a device off of the charger with the battery installed, reduces battery life expectancy; mechanical damage reduces battery life expectancy. Heck, even storing a fully charged battery reduces battery life expectancy.

I use my Macbook Pro 12-14 hr/day, 6 days a week and, on average, get about a year out of a battery. If your wife got 2 years out of one, I'd say you beat the odds.

FWIW, I've been buying replacement batteries from these guys for a few years. They last just as long as Apple OEM batteries, at about half the price.

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Thanks for the info! I guess I knew some of that, but good to learn more.

What's odd to me though is that for all the other laptops I've owned/used and had the battery crap out, I've never seen a physical difference in the dead battery, nor have I had one that seemed to have a negative impact on the computer's performance (except for not holding a charge). Maybe it has something to do with where the battery is situated inside the MacBook? I know I sure perform poorly when something is jabbing me in my side.

Thanks!

[ralphbsz]

This is common with the older MacBook Pro's with replaceable batteries. I've seen an extreme case where the battery was swollen by about 1/8", and you could not close the battery compartment any more. My current battery (about 3 years old) is swollen ever so slightly, causing the touchpad to get overly sensitive, because it is getting squeezed from below. It's going to be replaced soon.

I don't know why swollen batteries also cause the laptop to run hotter, but that's definitely another common observation.

The fix is easy, and expensive: Go to the nearest Apple store, and buy a new battery. Last time I did that, it cost about $150. For older laptops (where the battery is user-replacable), they just give you a new one, and you take it home. For the newer ones (which have to be disassembled to find the battery), they will replace the battery in the store, but you have to make an appointment, or wait a day or two.

[pgym]

Thanks for the info! I guess I knew some of that, but good to learn more.

What's odd to me though is that for all the other laptops I've owned/used and had the battery crap out, I've never seen a physical difference in the dead battery, nor have I had one that seemed to have a negative impact on the computer's performance (except for not holding a charge). Maybe it has something to do with where the battery is situated inside the MacBook? I know I sure perform poorly when something is jabbing me in my side.

Thanks!

Most computer makers encase the lithium ion cells in a thick plastic shell to contain the expansion. Works great unless one or more cells ruptures. (I've seen it: it's not pretty.)

Also, some smart battery mfgs program the battery to quit charging after a certain number of charge cycles, regardless of the actual condition of the battery, so they never reach the point that they start to bloat. Kind of like Epson and HP inkjet cartridges are programmed to trigger the low ink warning when they hit 30% remaining and shut down at 12%.

The shell of battery for Macbooks/MB Pros with removeable is consists of a thin plastic base and a snap-on sheet aluminum cover. They're designed to fail well before one or more Li-on cells ruptures.

BTW, if your wife bought a replacement battery from Apple to replace the original battery and never got the original battery replaced under the battery recall, you may still be able to do so, even though the recall program "officially" ended in 2009. My SIL got hers replaced this past March: took her 15" 2008 MBP and bulging battery into the Apple Store. The genius took a look at the battery, looked up the serial # of her MBP and saw she had never exchanged her original battery, grabbed a new battery from the floor display rack, handed it to her and said, "There you go." Might be up to the individual store and genius, though, so no guarantees.

[pgym]

I've seen an extreme case where the battery was swollen by about 1/8", and you could not close the battery compartment any more.

Shoot, that ain't even a little pregnant.

HERE'S a bloated battery:

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That's what happened to my wife's battery, it bulged to the point where it made the keyboard and trackpad inoperable. Probably more like 1/8" bulge than that exploded battery (yikes).

I'll take it into the shop and see what I can do about it. It's an old computer we have already replaced, so I'm not going to buy a new battery. I think we have at least 5 computers in the house right now, it's kind of ridiculous...