Confirmed: My Mac Book Pro battery dies at 20% remaining

For a while, the battery in my Mac Book Pro has been acting strangely. When it gets down to 20% remaining, the system goes into deep sleep with no warning, and won’t come back out until I plug into AC power.

Apple released a Battery Firmware Update a couple of weeks ago to address this exact issue, but alas, it didn’t work on my battery.

To confirm it, I borrowed a spare MBP battery from Aaron at work, and this morning, ran on battery power down past 20% (all the way down to 6%, where I started getting the expected warnings). So I guess that confirms that it’s my battery.

Guess I’ll drop by the Apple store and see if they’ll replace it.