Colleague and PowerPage contributor Kenn Marks Sr. contributes some tips on calibrating your MacBook battery.
A customer's MacBook Pro was shutting down while displaying that it still had 20 percent power remaining. Following are some links to calibrating your battery so that the power remaining indicator is more accurate.
This should be done every 3-6 months as your battery ages and is used, the amount of charge it can maintain decreases so re-calibration is necessary to maintain accurate feedback to the user.
Every battery you use should be calibrated because they are all unique and contain built-in circuitry and serial numbers which your computer can track.
Here are the battery calibration instructions from Apple:
Other beneficial battery monitoring applications and widgets include:
- Jeremy Kezer's XBattery (US$15) which provides probably more information than you wish to see but is there if interested. Jeremy is the developer of the classic OS 9 MyBattery software.
- Chris Sinai's coconutBattery has the most downloads of any battery monitoring software but is a little less informative than XBattery. coconutBattery keeps a running log of the battery self tests so you can monitor battery degradation and then perform calibrations in a more informed manner, i.e. when you notice that capacity has diminished x% it should probably be re-calibrated.