How To Calibrate Your Macintosh Laptop’s Battery

All batteries will eventually experience diminished efficiency and storage capacity and will need to be replaced. However, regularly recalibrating your Lithium-ion battery will help to prolong your battery’s life and health which helps you to reduce the frequency with which you’ll have to buy a new battery

Apple recommends recalibrating your battery at time of purchase and then every few months after that. Battery University recommends recalibrating your battery every 30 charge/discharge cycles. Apple provides written instructions on how to recalibrate your battery. For years, I had a repeating event on my iCal calendar that sent me an email reminder which included a copy of Apple’s instructions. Recently, I switched and started to use Watts (30-day free trial, then $6.95) which lets me monitor the health of my battery, reminds me to calibrate my battery and then guides me through it.

Apple indicates that one should expect current Mac laptop batteries to retain 80% of their charge capacity after 1000 full charge/discharge cycles. Watts lets you keep an eye on this and alerts you if your battery is not healthy and needs to be replaced. If you have Growl, the notification application installed, then Watts can be configured to display useful notifications and reminders to recalibrate your battery. I recommend Watts, check it out, you might find it helpful.

Here’s a copy of Apple’s current instructions for recalibrating your battery if you own a MacBook, MacBook Pro, MacBook Air or PowerBook G4 with a dual-layer DVD drive.

• Plug in the power adapter and fully charge your PowerBook’s battery until the light ring or LED on the power adapter plug changes to green and the onscreen meter in the menu bar indicates that the battery is fully charged.
• Allow the battery to rest in the fully charged state for at least two hours. You may use your computer during this time as long as the adapter is plugged in.
• Disconnect the power adapter while the computer still on and start running the computer off battery power. You may use your computer during this time. When your battery gets low, the low battery warning dialog appears on the screen.
• At this point, save your work.  Continue to use your computer; when the battery gets very low, the computer will automatically go to sleep.
• Turn off the computer or allow it to sleep for five hours or more.
• Connect the power adapter and leave it connected until the battery is fully charged again.