Macbook Pro battery draining while plugged in

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Level 1

15 points

Macbook Pro battery draining while plugged in

I purchased a 15" MBP back in December of 2010, and I've had intermittent issues with the battery every few weeks. It's been nothing serious so far, but it's getting a bit worse with time.

Basically, I'll be using the MacBook Pro while plugged into the wall, and the battery charge will drain despite this. For example: Last night when I was finished using my MacBook, it had a full charge, and said "Charged" on the menu bar. This morning when I started it up and plugged it in, everything was fine: Still "Charged", and the powerlight on the mag connector was green. Fast forward to lunch, and despite not having unplugged the laptop, now it's listed as having 17% battery charge. It was also running off of the Power Adapter according to the drop down on the menu bar, so the adapter was supplying power for sure. In fact, when I unplugged the power adapter, the screen dimmed, and the battery level dropped from 17% to 13%.

I'm a bit concerned that the system was plugged in, running off the power adapter, and somehow was draining the battery. Is this cause for alarm? Is my laptop battery going bad after four months? Any help would be appreciated! Thanks.

15" MacBook Pro, Mac OS X (10.6.7)

Posted on Mar 31, 2011 11:33 AM

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Answer 1

Best reply

Matt_Moore

Level 1

25 points

Mar 31, 2011 12:11 PM in response to Carbonyl

I know it sounds silly, but maybe your cord was not plugged in all the way?

You could also have a faulty MagSafe board.

Try resetting the SMC:

1. Shut down the computer.

2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.

3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.

4. Release all the keys and the power button at the same time.

5. Press the power button to turn on the computer.

Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

Source: http://support.apple.com/kb/HT3964?viewlocale=en_US

(Scroll halfway down the page and click "Resetting the SMC on portables with a battery you should not remove on your own")

Message was edited by: Matt_Moore

Message was edited by: Matt_Moore

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Answer 2

eww

Level 9

53,028 points

Mar 31, 2011 12:19 PM in response to Carbonyl

What were you doing with the computer while this was going on? Did you have any bus-powered USB or FireWire peripherals connected? Were you loading the processors heavily? Was the display brightness turned way up? Was BlueTooth on? Were you browsing video-laden websites? Encoding video? Playing a 3D game?

When your computer is working hard, it can demand more than the 85 watts of power that the AC adapter can provide. At such times, it draws on the battery for the extra power it needs. This has been true of all MacBook Pros since the first ones were introduced in 2006, but the extrememly powerful early-2011 models seem to encounter the threshold much more often than earlier models. They probably just draw a lot more power all the time, so they're always closer to the adapter's upper limit than older models were when doing the same work (which, of course, they did more slowly).

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Answer 3

j3rryk

Level 1

0 points

Apr 3, 2011 10:21 AM in response to eww

I am having the same issue. 85w is not enough to power Starcraft 2 on my MBP8,2. I end up running out of battery power during play even when plugged in. This leads me to wonder whether these machines are capable of supporting a higher wattage supply. Are there 3rd parties that are selling a 85w+ supply?
Thanks guys.

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Answer 4

eww

Level 9

53,028 points

Apr 3, 2011 3:14 PM in response to j3rryk

The inevitable companion of a higher-powered AC adapter will be more heat for the machine to dissipate. If you do find a more powerful adapter on the market, your MBP may need a major cooling assist from some sort of external device as well.

The first thing to do is minimize all the power demands on the computer other than the game you want to play. Quit all other apps, turn off BlueTooth if possible, disconnect or turn off all bus-powered peripherals, turn down display brightness (a real biggie), and turn off KB backlighting.

Message was edited by: eww

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Answer 5

Feb 19, 2012 8:30 PM in response to Carbonyl

Having a similar issue, but I'm not doing anything intensive. I did a little photoshop work earlier, but that was only for about 10 minutes... but I am also having issues with my adaptor, and I am wondering if the adaptor is at fault...

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Answer 6

eww

Level 9

53,028 points

Feb 19, 2012 8:40 PM in response to egyptlang

Your adapter may be faulty, or it may be hindered by a noisy AC power supply or other devices in your building. Work through the suggestions in this article, and if nothing helps, take your computer and adapter in for evaluation:

http://support.apple.com/kb/TS1713

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Answer 7

Feb 23, 2012 8:57 PM in response to eww

Thing is, this is recent. I have not had any other issues like this in the 2 years I have had my laptop...

The adaptor is also 2 years old, and has not done any of this until recently. Again, I looked and my computer is charging even though it's been plugged in all day. I am confounded.. I was at 100% battery charge. Battery health is at 84%, and it has had 68 cycles. 2 years old. I am wondering what is causing this... weather its the battery or the charger. I'm not entirely sure. But I ALWAYS run off of the adaptor, the 9600M GT Nvidia card just drains energy.

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Answer 8

Jun 14, 2012 11:36 AM in response to Carbonyl

The main culprit in "power suck" on my MBP is often browser(s) + Flash plug-ins. Both Firefox and Safari will, on some video-containing pages of some sites, start the fans whirring and (observed in Activity Monitor) induce high levels of CPU usage. The only cure I've found is to quit and relaunch the offending browser. Granted, I'm running 10.6.8 - do folks have a better time of this under 10.7.4? MBP is 2011 MacBookPro8,2 @ 2.2GHz.

I wouldn't leave HTML5 video out of the "CPU hog" category either, but it isn't readily evident [in Activity Monitor] in the way the Shockwave Flash plug-in is.

I've also noticed that Google Drive reports a memory leak in Console logs - don't know if that triggers some contention when the browser's causing the CPUs to work so hard…

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