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mattonthemoon

macrumors regular
Original poster
Feb 25, 2007
215
17
Toronto, ON
First off, i love my rMBP, wouldn't return it for the world.

But i observed the following and wanted to know if it was normal?

Played about 2.5 hours of Diablo 3 tonight, power was connected.

Settings were 2880x1800, all High Settings, Shadows Off, no AA...

Anyway while playing i noticed my battery charge go from 93% to 90% even though it was plugged in the whole time.

Is this normal under heavy load?

Thanks.
 
This is normal. If the Magsafe cannot provide enough power, the machine will draw power from the battery as well. This is why on some later Macbooks and Pros that had a removable battery, the performance would be reduced if the battery was removed.
 
Quad core: 45W
SSD: 5W
Chipset: 10W
GPU: 50W?
Screen: 30W?

Magsafe 2: 85W

The numbers suggest that the power adapter does not provide enough power if you were to run everything at 100%.
 
Is this normal under heavy load?
Yes. It's normal for your MBP to draw power from both AC and battery during periods of extreme demand, such as gaming or other multimedia operations. This can cause your battery to stop charging or even drain. Read the AC POWER section of the following link. This should answer most, if not all, of your battery questions:
 
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