How does my Macbook know the battery percentage?
Sometimes when I turn my computer on, it says the battery is, for example, 33%. But after 5min it says the battery is, for example 38%.
MacBook Pro, OS X Yosemite (10.10.5)
It uses both voltage and the sum of the amount of current drawn from the battery since it was last charged.
It is not that accurate really.
Also there is a micro memory chip inside the battery to communicate...
If you have ran the battery flat, it may never hold a full charge long, after.
• About Mac notebook batteries - Apple Support
• How to store Apple notebook computers and their batteries - Apple Support
Maximizing Performance - Batteries - Apple:
http://www.apple.com/batteries/maximizing-performance/
• Apps can affect Mac performance, battery runtime, temperature, and fan activity - Apple Support
• Apple Portables: Troubleshooting MagSafe adapters - Apple Support
Depending on the MacBook Pro model you may need to consider a battery
replacement, if the numbers and duration times do not recover. A visit to an
Apple Store or authorized Apple service provider may be helpful if testing or
a diagnostic is involved. User-replaceable batteries can be owner-replaced
and several iFixit repair guides show how to take out some models.
If battery or power issues present odd symptoms or issues, read SMC reset:
• Reset the System Management Controller (SMC) on your Mac - Apple Support
Note that if you take out a built-in battery, Apple service may decline to help;
some of these are said to be non-user replaceable. Been reported third-party
batteries may present an issue if you later revisit Apple, in such instance.
In any event...
Good luck & happy computing! 🙂
Battery Percentage!
