A macbook's battery has three charge numbers:
- The current charge
- The maximum charge
- The design capacity
Even if a Macbook remains plugged in, OS X does not attempt to chargeāas long as (1) is 95% of (2), which is why the percentage in the notification bar will often be between 95% and 100%.
These two numbers are in contrast with a battery's "design capacity".
Coconut Battery is the only software I've found that reports a Macbook battery's "design capacity".
This design capacity does not appear in Apple's specs, in System Information, or at everymac.com.
How does Coconut Battery determine the design capacity of a battery?
Best Answer
You can find this information along with much other battery and/or system information from the command
This command, according to its man page, does:
1: heirarchical [sic]
Using a filter by class name (
AppleSmartBattery
for battery) to get only battery-related information:Will print something like this:
The field you are looking for is
DesignCapacity
. For convenience, filter it out withgrep
(unit is milliamp-hours, or mAh):Your
DesignCapacity
field may not display6330
as its value. I'm using a 13" mid-2014 rMBP, but you may be using another system with different battery ratings.Apart from battery information,
ioreg
can be used to find out more about your system and other peripherals - somewhat like a command-line System Information tool.If you're looking for a code-implementation of this command, take a look at Beltex's SystemKit over on Github. It's one of the coolest Swift libraries I know of.
Disclaimer: not affiliated to SystemKit or Beltex. Just a happy user of SystemKit.