Greetings,
This is the only issue I have had with Lion, on my Macbook. After the upgrade, I took the machine out on the patio, as I usually do, and the battery lasted less than 2 hours, and it was fully charged. I've seen this before on a machine that has had a lot of use, but this one hasn't
I immediately suspected the battery meter of being out of calibration, figuring something in the Lion battery indicator of not being true. The meter is what shuts your machine off - the battery could be half charged, still.
I performed a calibration by charging the machine up to full, and ran it down until it shut off, and wouldn't come back on. Just letting it discharge, with use, until it goes to sleep, until it won't restart, is enough. I did this twice, but usually once is enough.
Now the Macbook runs for nearly 4 1/2 hours with normal, and steady use. I've charged and discharged it several times since then, and it performs correctly, still.
Apple recommends to do this once a month, but I do it every other month, except this time, as I had just installed Lion, and that's when the issue raised its head. It's funny, it didn't affect my Macbook Pro, after the Lion update.
Here's an article from Apple about it;
http://support.apple.com/kb/HT1490
Cheers,
M.
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