May 22, 2009
Checking Your Mac Notebook Battery Health with coconutBattery
Is your Mac notebook’s battery not lasting quite as long as it used to? Just curious about or obsessive over keeping your laptop healthy? Christoph Sanai at coconut-flavour.com has written an excellent little utility for checking the current charge and capacity of your Mac notebook’s battery.
Available at coconut-flavour.com, coconutBattery is a free utility for viewing battery data on your Mac notebook. Below is a view of my battery’s current info.
As you can see in the bottom portion of the window, my Mac is 6 months old. Over those 6 months, I’ve put the battery through 31 load cycles. Load cycles are the number of times your battery has been discharged and recharged. Over time as you charge and discharge your battery, the capacity becomes diminished and the battery won’t last as long as when it was new.
In the screenshot above, you’ll notice that the original battery capacity for my laptop—a MacBook 13″ Unibody from Late 2008—was 4100 mAh, or milliamp hours. The current capacity is 4104 mAh, so the health of my battery is 100%. It’s common to see the current battery capacity fluctuate a bit between charges.
To ensure accurate display of remaining capacity and the longevity of your battery, it’s best to calibrate the battery once a month or so. It may sound complicated, however it’s very easy. In the MacBook, MacBook Pro, and PowerBook G4 15-inch Dual Layer SD, the battery is calibrated as follows.
- Completely charge the battery.
- Completely discharge the battery. Use the computer off the charger until you get the warning that the computer is running on reserve power and will sleep soon. Continue using the computer until it goes to sleep, powering itself off.
- Allow the computer to remain powered off for 5 hours.
- Connect the charger and completely charge the battery.
For older PowerBook G4’s and iBooks, the calibration method differs slightly, and you may find more informaton here: Apple Portables: Calibrating your computer’s battery for best performance.
