How can I maximize the lifespan of my portable computer’s battery?

A properly maintained Apple portable battery is designed to retain 80% of its original capacity for 1,000 full charge and discharge cycles (older models are designed for 300 cycles). Charge cycles are cumulative so if you use 25% of your battery each day and recharge it every night, after four days you will have completed one full cycle. You can see how many charge cycles your battery has gone through by opening the System Profiler or System Information application from Macintosh HD/Applications/Utilities. Select Power from the left bar of options (under Hardware) and look for the number next to “Cycle Count” under “Battery Information.”

How to Calibrate Your Portable Mac's Battery

When you plug in a new portable computer or a new battery for the first time, you should fully charge the battery. Also run Software Update from the Apple menu () to install any battery performance updates that Apple may have released for your computer. Once it’s fully charged, make sure to keep the power adapter attached for two hours. Then unplug your Mac and work off battery power until the computer's battery is almost depleted. Save your work and close all applications once the battery gets down to a few percent, before the computer goes to sleep. Once the computer falls asleep, allow the battery to remain depleted for 5 hours or more (the computer can be turned off or just asleep). Then connect your power adapter and leave it connected until the battery is fully charged again. Apple recommends repeating this procedure every few months.

To properly maintain the battery, it’s important to keep the electrons moving occasionally. Apple does not recommend leaving your portable plugged in all the time. You should charge and discharge the battery (a.k.a. add one cycle count) at least once a month. Macs work best in the same temperatures humans like, from 50° to 95°F. Storing your Mac in temperatures less than -13° or higher than 113°F can damage the battery; so don't leave your Mac in a hot car.

Although the newest Apple batteries are designed to last up to 5 years, your performance will vary. Tekserve can replace your battery at anytime or sell you an external battery for use between charges.

Read "How can I use my portable computer on battery power for longer?" for more tips.

Published March 24, 2009 12:00 PM
Last modified on November 17, 2011 4:47 PM