Computer batteries have a limited lifespan and degrade over time, so they’re often the first thing to go in a Mac laptop. You can replace a battery yourself or pay Apple to do it, but you should check its health. first. Any battery life issues you’re having could be due to a runaway process or just heavy use.
Check the Battery Cycle Count on Your Mac
A charge cycle is one full charge and discharge of the battery. Every modern Mac battery is rated for 1000 cycles; some older models (pre-2010) are rated for 500 or 300 cycles. While the battery won’t suddenly fail when it reaches its limit, it will start to hold less and less charge as it approaches that limit. Eventually, you’ll need to keep your Mac connected to its power cable to use it.
To check how many charge cycles your battery has been through, hold down the Option key, click the Apple icon at the top left corner of the screen, and then select the “System Information” command. If you don’t hold down the Option key, you’ll see an “About This Mac” command, instead.
In the system information window, expand the “Hardware” category on the left, and then select the “Power” option.
In the right pane, you’ll see all the stats for your battery. The “Cycle Count” entry is under the “Health Information” section.
The MacBook in our example has a cycle count of 695. The battery doesn’t need to be replaced yet, but it probably will need to be done later this year. If there is a problem with your battery, the “Condition” entry (which shows Normal in our example) will display something like “Service Battery.”
Get a Bit More Information with coconutBattery
System Information has most of the data you need to assess your battery’s health, but it’s not very well laid out and could provide a bit more information. For example, it tells you your battery’s current maximum capacity but not it’s original capacity. If you want a little bit more info that’s easier to understand, download the free app coconutBattery.
When you run the app, you’ll see something like the screenshot below.
As well as the cycle count, this app shows us that the battery now has a Full Charge Capacity of 7098 mAh. When it was new, it had a capacity of 8755 mAh. Losing 15% capacity over almost three years isn’t too bad at all.
If you’ve got an older MacBook, the battery almost certainly holds less charge now than it did when it was new. With either System Information or coconutBattery, you can quickly see how much capacity it’s lost and whether it needs to be replaced.