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Level 4

1,345 points

Question about MacBook Pro retina 13" battery life

Since getting my new MacBook Pro retina 13" last week I've left it plugged in. Today I need to take it out to a class I'm giving. Last night I unplugged it and put it in a case for this morning. I'm leaving in about 30 minutes.

Out of curiousity I woke it up from sleep before and was surprised to see it had dropped to 97% battery overnight. But it was asleep all night. And my energy settings don't have "power nap" turned on while off-battery.

So why the drop of 3% overnight? My iPad doesn't do that.

Thanks,

doug

iMac, Mac OS 9.0.x, iMac (21.5-inch Late 2009, 12 GB)

Posted on Jan 4, 2014 4:35 PM

34 replies

Sep 5, 2014 10:33 AM in response to aar-mbpro

Maybe i should be more clearer about my confusion. Keeping it on charge when near an adaptor would mean it would stay at 100% charge most of the time which has been discouraged in other parts of the thread and in others encouraged. so which is most correct to go by?

OGELTHORPE

Level 9

57,305 points

Sep 5, 2014 11:02 AM in response to aar-mbpro

If an AC outlet is available, I always will have the MBP connected to the power adapter. If however I have not used the MBP for a month under battery power, then I will use it under battery power alone until about the 40% discharge level. Then I will repeat the process, ie. power adapter connected as much as possible. This will keep the battery happy and maximize battery life.

For additional professional information, you might look at the articles available at the Battery University web site. It is of a somewhat technical nature.

Ciao.

Sep 6, 2014 9:10 AM in response to OGELTHORPE

This is the advice that has been continuously repeated through out the thread and i will definitely follow this advice. Just one thing that confuses me is apple recommends not leaving it plugged in all the time. What does this refer to exactly? Also read on one of those batt uni links that storing it at %100 is not good either and after an evening of use thats what i will be doing until lets say the next afternoon. Is this time for storage ok at that percentage?

OGELTHORPE

Level 9

57,305 points

Sep 6, 2014 12:29 PM in response to aar-mbpro

aar-mbpro wrote:

. Just one thing that confuses me is apple recommends not leaving it plugged in all the time.

Note that I said that at least once monthly one should run it under battery power to about the 40% discharge level which should keep the battery happy.

Also read on one of those batt uni links that storing it at %100 is not good either and after an evening of use thats what i will be doing until lets say the next afternoon. Is this time for storage ok at that percentage?

That is meant for long term storage, two weeks or more (approximately). If the MBP is going to be used the next day, do not obsess about that.

Ciao

Question about MacBook Pro retina 13" battery life