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macrumors 6502
Original poster
Jan 7, 2009
I just popped open my MBP (13in 2018) and it was at 97% battery. within the last 15 minutes I goofed off a little in iTunes, looked at Facebook, and wrote this post. In that amount of time my battery dropped to 90%. This can't be normal. Am I wrong?

I am connected to internet via wifi.
Screen brightness at approximately 50% brightness.


macrumors regular
May 28, 2017
Does your battery do this regularly? It's possible that the initial 97% was a hold-over from before the computer had been closed, and it had lost a little more on standby. Or perhaps updates were being downloaded in the background. If your battery life is normally fine, then I wouldn't worry about this oddity. If your battery drops very quickly more often, then you should check for software processes that are consuming a lot of power. Only after that would I worry about a battery problem.


macrumors 601
Mar 10, 2016
15 minutes.
I have not but will start. Stay tuned.

I leave it running in the bar at the bottom. It's then really easy to see when the system is getting hammered just by a quick glance. I've occasionally caught run away processes, web pages that seem to be poorly optimized etc.


macrumors G3
Nov 23, 2011
Batteries aren’t digital so they won’t deplete linearly. The percentage is a best guess.

I’d use it over the course of a number if hours and see how long it takes to hit the red low battery warning. Usage over a longer period of time should give you an idea if it’s performing within normal parameters.
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