9 Replies Latest reply: Aug 28, 2011 10:46 AM by hayesk
midimauve Level 1 Level 1 (0 points)
Hi,

I have this MBP 13 inch 2011 version and it's 3 weeks old with 97% battery health and 11 cycles.

Is this normal for a 3 week old to have 97% battery health?
I am also using Coconut Battery and iStat Pro widget.

Your replies will be of big help.

Thanks.

Mac Book Pro i5, Mac OS X (10.6.6)
  • 1. Re: MacBook Pro early 2011 version battery health
    Retired Engineer Level 4 Level 4 (2,735 points)
    Apple considers 80% or better full charge capacity to be a good battery.
    Current battery technology does not permit making every battery be 100% of the design target capacity value.
  • 2. Re: MacBook Pro early 2011 version battery health
    eww Level 9 Level 9 (52,975 points)
    Your battery's reported Health will fluctuate up and down by several percentage points from day to day and week to week throughout the battery's useful life.
  • 3. Re: MacBook Pro early 2011 version battery health
    midimauve Level 1 Level 1 (0 points)
    But in this current state, is it okay to have 97% health for a 3 week old unit?
  • 4. Re: MacBook Pro early 2011 version battery health
    midimauve Level 1 Level 1 (0 points)
    and another thing, i am using my mbp via power adapter and it's fully-charged 100%, there are times that when i turn it off for a while to rest, then power it on, the battery will show 99% while on power adapter. is it normal?
  • 5. Re: MacBook Pro early 2011 version battery health
    eww Level 9 Level 9 (52,975 points)
    Yes to both questions. What you are seeing is completely normal. 3% is well within the normal range of fluctuation for battery health — the health readout simply isn't any more precise than about ±5%. If your battery's health declines continuously, falling below 80% and remaining there before you've put 1000 cycles on the battery, then you can take it in and ask to have the battery tested for defects. If it's defective, it will be replaced.

    The battery automatically stops charging when it's full, and doesn't begin charging again, even if the AC adapter remains connected, until the battery's charge level falls below 95%. This is by design. The battery, like every other battery of any kind, drains slowly whenever it isn't being charged, even if no power is being drawn from it by any connected device. This is one of the properties of all batteries. The reasons for stopping charging when the battery is full are a) to prevent overcharging, and b) to permit the battery and the charging circuitry to be cool much of the time (charging generates heat, and heat accelerates the decay of batteries, so avoiding it when the battery doesn't need to be charged is desirable).
  • 6. Re: MacBook Pro early 2011 version battery health
    Booita Level 1 Level 1 (0 points)
    Hi!
    I've got my MBP 13" for 1 week and coconut says that my battery is 95% of the design capacity, with just 4 load cycles. Is this still normal? What is the better way of taking care of my battery? I need my computer for work so, I'll use it around 10 hours everyday... Should I left it plug in all the time?
  • 7. Re: MacBook Pro early 2011 version battery health
    eww Level 9 Level 9 (52,975 points)
    Yes, that's normal too, particularly if you haven't yet [calibrated the battery|http://support.apple.com/kb/HT1490].

    You should plug your computer into AC power whenever you can conveniently do so, and use it on battery power whenever AC power is not available. If AC is always readily available and you never actually need to use the battery, make a point of using the computer a little on battery power anyway: roughly enough to cause a battery cycle each week on average. The battery's longevity will benefit from regular, light use. Frequent heavy use (draining the battery all the way every day or two) and never using the battery at all are both harmful to its longevity. Cycling the battery anywhere from 1/2 to 3 times a week is healthy, as long as the battery isn't being drained down to zero each cycle.
  • 8. Re: MacBook Pro early 2011 version battery health
    cmathena Level 1 Level 1 (0 points)

    Go to your local apple store. be sure to call and make an appointment.  They will replace your battery to a good one for about $30.00.  It will last you at least 12 hours, mine lasts 14.

  • 9. Re: MacBook Pro early 2011 version battery health
    hayesk Level 1 Level 1 (10 points)

    According to the calibration article at http://support.apple.com/kb/HT1490

    MacBooks will built-in batteries don't need calibration.