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drsox
Mar 1, 2013, 09:30 AM
My battery life is now only 5.5 hours. The Apple "spec" for this is 7 hours or so.

I upgraded to ML and the battery time degraded but it seems to be running down much faster than expected.
Is this becoming a bad battery ? What are other folks' stats for this ?

Here's my data :
Nov 2011 13in MBA being used just for normal tasks (Safari, EMail, Excel). Nothing heavy on CPU usage.
Battery stats are : Health 87%. Cycles 235.
Time remaining when 99% charged 5hr25min.
Power info (from System Report) Amperage (mA): -1864 Voltage (mV): 7569.



BeeJee
Mar 1, 2013, 11:16 AM
My battery life is now only 5.5 hours. The Apple "spec" for this is 7 hours or so.

I upgraded to ML and the battery time degraded but it seems to be running down much faster than expected.
Is this becoming a bad battery ? What are other folks' stats for this ?

Here's my data :
Nov 2011 13in MBA being used just for normal tasks (Safari, EMail, Excel). Nothing heavy on CPU usage.
Battery stats are : Health 87%. Cycles 235.
Time remaining when 99% charged 5hr25min.
Power info (from System Report) Amperage (mA): -1864 Voltage (mV): 7569.

Yeah, your health to cycle ratio is ugly for sure. Looks like you use the battery, some people keep theirs plugged in all the time which is bad. It's supposed to be 80% after 1000 cycles so you're more than halfway there after a quarter of use.

drsox
Mar 1, 2013, 11:30 AM
Yeah, your health to cycle ratio is ugly for sure. Looks like you use the battery, some people keep theirs plugged in all the time which is bad. It's supposed to be 80% after 1000 cycles so you're more than halfway there after a quarter of use.

Yes, I use it during the day and plug it in overnight. At least that's what I used to do, now I have to plug it in again at 4pm or so otherwise it would empty early. Fortunately it's on AppleCare so I'll give it another year to see how it goes and then complain.

GGJstudios
Mar 1, 2013, 11:38 AM
My battery life is now only 5.5 hours. The Apple "spec" for this is 7 hours or so.

I upgraded to ML and the battery time degraded but it seems to be running down much faster than expected.
Is this becoming a bad battery ?
It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. For further details, read the CHECKING STATUS AND HEALTH section of the following link.

There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
Apple Notebook Battery FAQ (http://forums.macrumors.com/showpost.php?p=9875442&postcount=23)

Yeah, your health to cycle ratio is ugly for sure.

It's supposed to be 80% after 1000 cycles so you're more than halfway there after a quarter of use.
Battery health doesn't decline in a straight line or in direct correlation to time or number of cycles. It may decline rapidly at first, then maintain a percentage for a long period of time. It will fluctuate up and down over time. You can't project current health and cycles to accurately predict future health percentages.

drsox
Mar 1, 2013, 11:56 AM
It is perfectly normal if your battery health (maximum capacity) is more or less than 100%, even when brand new, or if it fluctuates up or down over time. For further details, read the CHECKING STATUS AND HEALTH section of the following link.

There are many factors that impact your battery life. See the BATTERY LIFE FROM A CHARGE section of the following link for details, including tips on how to maximize your battery life.

The link below should answer most, if not all, of your battery/charging questions. If you haven't already done so, I highly recommend you take the time to read it.
Apple Notebook Battery FAQ (http://forums.macrumors.com/showpost.php?p=9875442&postcount=23)


Battery health doesn't decline in a straight line or in direct correlation to time or number of cycles. It may decline rapidly at first, then maintain a percentage for a long period of time. It will fluctuate up and down over time. You can't project current health and cycles to accurately predict future health percentages.

I've done all that. The battery health has been slowly declining month by month with occasional upticks of 1% or so when I have had to reinstall ML or Lion. What worried me was the recent evident inability to get through a day of intermittent use without having to recharge. Some of this is due to ML but some must be due to the battery getting weaker as a unit.

GGJstudios
Mar 1, 2013, 12:01 PM
I've done all that. The battery health has been slowly declining month by month with occasional upticks of 1% or so when I have had to reinstall ML or Lion. What worried me was the recent evident inability to get through a day of intermittent use without having to recharge. Some of this is due to ML but some must be due to the battery getting weaker as a unit.
As your battery health (maximum capacity) declines, so will the time you can run on a charge. Look at the BATTERY LIFE FROM A CHARGE section of the Battery FAQ. It's possible you have some processes running that are consuming resources and draining the battery faster.

Mlrollin91
Mar 1, 2013, 01:10 PM
I'm at 132 charge cycles with 90% health on my 2012 11" MBA. I keep good track of it, every 5 charge cycles I write down the health %. I've gone from 103% to 87% back up to 95% all within 25 charge cycles. The only time I really pay attention to it, is when it drops to the low 80s. Once it breaks 80% and has less than 1000 charge cycles is the time you should consider taking it in. But like previously stated its pretty normal to go way up and way down.

drsox
Mar 1, 2013, 02:01 PM
I'm at 132 charge cycles with 90% health on my 2012 11" MBA. I keep good track of it, every 5 charge cycles I write down the health %. I've gone from 103% to 87% back up to 95% all within 25 charge cycles. The only time I really pay attention to it, is when it drops to the low 80s. Once it breaks 80% and has less than 1000 charge cycles is the time you should consider taking it in. But like previously stated its pretty normal to go way up and way down.

That's reassuring to know. Thanks. Mine doesn't jump about like that; it's more of a steady drip drip.

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As your battery health (maximum capacity) declines, so will the time you can run on a charge. Look at the BATTERY LIFE FROM A CHARGE section of the Battery FAQ. It's possible you have some processes running that are consuming resources and draining the battery faster.


Maybe it's just ML that's accelerating the decline.

GGJstudios
Mar 1, 2013, 02:02 PM
Maybe it's just ML that's accelerating the decline.
It's most likely specific processes in ML. Check the 3rd bulleted item in the BATTERY LIFE FROM A CHARGE section.

drsox
Mar 1, 2013, 02:19 PM
It's most likely specific processes in ML. Check the 3rd bulleted item in the BATTERY LIFE FROM A CHARGE section.

It's going to be Safari WebContent that's causing it : 24% CPU usage continuous. I'll have to live with it as I already have ClickToFlash running.