Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

dontwalkhand

macrumors 604
Original poster
Jul 5, 2007
6,543
3,196
Phoenix, AZ
Hi guys, I am new here. I have a MacBook pro, and I have a little problem with the battery meter. The battery gets fully charged to 100%, but over time, the battery meter goes down a couple %. Right now it is at 97%. If I unplug it and use it on battery for a while, and then when I plug it in, it charges to 100%, then over time, it would drop a few percent again. Could it be a problem with the battery, or is this completely normal?

Sorry if the grammar is a bit off, It is really late, but I don't want to sleep yet :p

Thanks in advance.
 
Hi guys, I am new here. I have a MacBook pro, and I have a little problem with the battery meter. The battery gets fully charged to 100%, but over time, the battery meter goes down a couple %. Right now it is at 97%. If I unplug it and use it on battery for a while, and then when I plug it in, it charges to 100%, then over time, it would drop a few percent again. Could it be a problem with the battery, or is this completely normal?

Sorry if the grammar is a bit off, It is really late, but I don't want to sleep yet :p

Thanks in advance.

Please define the length of time that it takes to drop a couple of percentage points.

As well how old is your computer, and would you be able to post some of the numbers on the battery health available from 'About this Mac'/More Info/Power

That information should allow myself or someone else to make an informed comment

Sopranino
 
Please define the length of time that it takes to drop a couple of percentage points.

As well how old is your computer, and would you be able to post some of the numbers on the battery health available from 'About this Mac'/More Info/Power

That information should allow myself or someone else to make an informed comment

Sopranino

I have been leaving the Mac powered on for a few days now. This happens if I leave it on for a day or two. (I plan to not shut it down unless I need to for I now charge my phone, headset, and my iPod on the computer, and I need these charged overnight). I purchased this computer in February. I have MacOS 10.4.10

Anyways, here is all the text from About This Mac > More Info > Power:

System Power Settings:

AC Power:
System Sleep Timer (Minutes): 0
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 10
Automatic Restart On Power Loss: No
Wake On AC Change: No
Wake On Clamshell Open: Yes
Wake On LAN: Yes
Display Sleep Uses Dim: Yes
Battery Power:
System Sleep Timer (Minutes): 5
Disk Sleep Timer (Minutes): 10
Display Sleep Timer (Minutes): 1
Wake On AC Change: No
Wake On Clamshell Open: Yes
Display Sleep Uses Dim: Yes
Reduce Brightness: Yes

Battery Information:

Battery Installed: Yes
First low level warning: No
Full Charge Capacity (mAh): 6114
Remaining Capacity (mAh): 5937
Amperage (mA): 0
Voltage (mV): 12461
Cycle Count: 22

AC Charger Information:

Connected: Yes
Charging: No

Hardware Configuration:

UPS Installed: No
 
Thanks for posting the details.

I would say that there does not appear to be any problems evident. The way the battery charging system works is like this:

The charging system will charge the battery up to 100% (some systems report 100% as 99%, but it is still full) if the current battery charge is below 95%.

Once the battery has reached 100% the charging system will not apply anymore charge to the battery until it has dropped below the 95% threshold.

All rechargeable batteries will loose a bit of charge over time, even if there is no draw on the battery itself.

Considering that it seems to be taking a couple of days to drop down to 97% you have nothing to be concerned with. Everything is running as it should. Your battery health looks great from the numbers that you've posted.

Sopranino
 
If it's a % or two over several hours or a day or whatever that's perfectly normal.

Mine drops around 25% overnight, which isn't normal. :mad:
 
Thanks for posting the details.

I would say that there does not appear to be any problems evident. The way the battery charging system works is like this:

The charging system will charge the battery up to 100% (some systems report 100% as 99%, but it is still full) if the current battery charge is below 95%.

Once the battery has reached 100% the charging system will not apply anymore charge to the battery until it has dropped below the 95% threshold.

All rechargeable batteries will loose a bit of charge over time, even if there is no draw on the battery itself.

Considering that it seems to be taking a couple of days to drop down to 97% you have nothing to be concerned with. Everything is running as it should. Your battery health looks great from the numbers that you've posted.

Sopranino

Thanks very much, this is helpful to know. I am not new to Macs, but I am a complete n00b when it comes to batteries and all that :)
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.