Macbook Pro battery discharging during standby

Discussion in 'MacBook Pro' started by SouthernMac, Dec 15, 2008.

  1. SouthernMac macrumors member

    Nov 25, 2007

    I have a MBP which I purchased in August of 07. I have never had a problem with it. However, recently I have noticed that the battery is discharging when the computer lid is shut and the laptop is not plugged in. This weekend I left the laptop unplugged with a full charge and when I arrived home, the battery was around 17%. Also, the health of the battery is 75%.

    Is this normal? Is there anything I can do to fix it?
  2. cawesjmu macrumors 6502

    Apr 4, 2004
    Richmond, VA
    I have this issue too. I had my battery replaced about 6 months ago due to the health being around 50%. It had well less than the 300 cycles acceptable. I have about 115 cycles now with health at 73% and was planning on taking it in to get another new battery when I had some time to drive out to the apple store. I don't think it's normal and would suggest you try for a new battery as well. It shouldn't loose that much power in sleep mode.
  3. SouthernMac thread starter macrumors member

    Nov 25, 2007
    when you say take it back and get another one, do you mean buy one? or did the Apple store give you another battery under warranty?
  4. djsmart macrumors newbie

    Mar 15, 2009
    Sorry to bring this back, but there is no positive answer from the OP issue.
    I have the exactly same problem and I don't think a batery replacement will solve the issue. The problem is NOT the battery life, the problem is battery not keeping its charge when in sleep mode (it will hold the charge when the MPB is shut off). Does anyone can help with this before I move my feet to a apple store? Thank you.
  5. plinden macrumors 68040


    Apr 8, 2004
    The battery discharging during sleep is normal. This is because the Mac is still on - it's in "safe sleep" (where it is using the default "hibernatemode" of 3), which means the computer is still drawing power to maintain the RAM. This allows it to wake up faster, but the contents of RAM are written to /var/vm/sleepimage so if the battery discharges completely while sleeping, you still get back to the same state on connecting to power and starting up, ie. it goes into true hibernate mode.

    True hibernate mode is 1, where the Mac actually powers off. This takes a good deal longer to start, but you get no power drawn from the battery. You can set this from the command line by typing: sudo pmset -a hibernatemode 1.

    I just keep my MBP in the default hibernatemode. I don't care about the 2-3% battery drain in the couple of hours between disconnecting it in the morning and getting to work.
  6. djsmart macrumors newbie

    Mar 15, 2009
    Thank you for your kind repply. Looking at your answer I started to wonder if there is a Hibernate mode 2?
    Also, I wouldn't care if I have lost just 3% overnight, but sometimes I close the lid with the battery showing 1:30 hour remaining and when I open the lid a couple of hours late I see a red battery with only 0:25 remaining :( this is more than 60% lost.
    Sorry for my bad english, I am not native.
  7. Nickmack macrumors newbie

    Feb 24, 2010

    Same problem here. Leave the macbook pro for 4 hours in sleep mode, it loses 15% of the charge. If I let it go to sleep for a few hours when it is almost discharged (like 15 % left), it won't be possible to wake him up without the power supply (the battery gets discharged much more than it should without shutting down). The battery has 90 % health and about 90 cycles, it is 4 months old. I replaced back then an older battery that had less than 40 % health.

    The macbook pro is more than 3 years old and it really doesn't seem normal to me.

    Any ideas are welcome!
  8. Whackintosh macrumors 6502


    Mar 8, 2009
    Montreal, Quebec
    I think it's outrageous that people have trained themselves to feel that this kind of battery drain is "normal". If I leave my 2008 UMBP, fully charged, in sleep mode for two days, it's got no charge left at all. Meanwhile, my 2006 1st gen Macbook can hold a charge in sleep mode for over a week. Something is very rotten here, and it would be nice if Apple finally addressed it.
  9. Dan73 macrumors 6502a

    Jul 30, 2009
    Uhm are they using the same type of sleep? One may keep the RAM powered up while the other might save to the HD and completely power off.
  10. iLog.Genius macrumors 601


    Feb 24, 2009
    Toronto, Ontario
    Not to be rude or anything but how is it outrageous? It would only be outrageous if there was no answer as to why there is a drain. Also, you can't compare your 2006 MacBook to a 2008 MacBook Pro, there could be many differences as to how each handles hardware. I can't say for earlier MacBook Pro's (no hardware training for those models) but it is COMPLETELY NORMAL for the Late-2008 uMBP to lose 1-2 percent each hour in sleep mode when it's not connected to a power source.

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