My wife and I have had our MacBook for about 6 months now. We really love it. Actually, it is my wife’s but she allows me to use it, if I am nice. After a few months the battery in the MacBook seemed like it was not lasting as long as it should. So, I went to the Apple Knowledgebase and got the following information:
To calibrate the battery:
1. Plug in the MagSafe power adapter and fully charge the MacBook or MacBook Pro battery until the light on the MagSafe connector changes to green and the Battery icon in the menu bar indicates that the battery is fully charged.
2. Allow the battery to rest in the fully charged state for two hours or longer. You may use your computer during this time as long as the power adapter is plugged in.
3. Disconnect the power adapter with the computer on and start using it with battery power. When the battery’s charge gets low, you’ll see the low battery warning dialog on the screen.
4. Continue to keep your computer turned on until it goes to sleep. Save your work and close all applications when the battery’s charge gets low and before the computer goes to sleep.
5. Turn off the computer or allow it to sleep for five hours or longer.
6. Reconnect the power adapter and leave it connected until the battery is fully charged. You may use your computer during this time.
This is taken directly from Apple’s web site. I followed this procedure to calibrate the MacBook battery and it worked very nicely. Here are some of my observations after having done this procedure. First, follow the directions explicitly. I know they sound a bit too complicated, but they work. Second, this is an all day procedure. I started in the early morning and finished around dinner time if I recall correctly. Finally, by allowing the battery to run down letting the MacBook go to sleep you will not lose any data. At the end of the procedure just plug in the MagSafe power adapter and let it charge.
Apple suggests doing this every 2 months or so. I am not sure I will do it that often, but every few months certainly is not a bad idea. There was a definite improvement in the MacBook battery life using this procedure. It works. Also, according to Apple this procedure works for the MacBook Pro as well. A little preventive maintenance will go a long way in keeping our Macs working properly.