Swollen Battery
From Appledefects
Update: The direct cause of the expanding battery packs is because it is a LiPo battery back.
There have been multiple reports floating around the internet with claims of MacBook Pro batteries swelling in size due to excessive heat. The reports are becoming more and more common.
From http://www.macfixit.com/article.php?story=20060622103345459
We've extensively covered an issue where the MacBook Pro's battery gradually swells, apparently due to overheating. In mild cases, batteries swell but remain functional. In these cases, keyboard and/or trackpad functionality is sometimes affected by the rising of internal components.
In severe cases, the swelling is visually striking, and users are eventually left with non-functioning batteries. Sudden shutdowns while charge remains are usually precursory to such failures.
Our in-house MacBook Pro's battery has now fallen into the severe category, swelling significantly, with the unit shutting down routinely when running only from battery power.
Here are some picture of our swollen battery:
More pictures:
A Canadian user adds this image of his "expanding" Macbook battery. The photo was taken in April 2006, of a "week 8" Macbook that Apple replaced after some considerable badgering. (The bottom of the battery should lie flat against the edge of the screen!)
Another report of this issue here: http://macnewbie.wordpress.com/2006/06/26/battle-of-the-bulge/
Apple Warranty Repairs for this issue
The swollen and over-heating batteries are covered by a widespread Sony-manufactured battery recall that was in the news a few months ago. Here is the url for the exchange program:
https://support.apple.com/macbookpro15/batteryexchange/
If your battery is doing this, pull it and run on AC while you get an exchange. It will keep swelling and running hotter until it is useless.
Links to Expanded/Swollen batteries
http://web.mac.com/blockheads88/iWeb/Site/MBP%20Battery.html




