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typecase

macrumors 6502
Original poster
Feb 2, 2005
394
400
Ever since receiving my Macbook Pro, I've been really paranoid about ruining my battery especially when it's plugged in. I calibrated it as per the instructions on Apple's site when I initially got the machine. Will running the computer off the AC adapter most of the time somehow shorten the lifespan of the battery? Is it better to run it off battery power until its almost completely discharged and then recharge it again? Any advice appreciated.
 

vader26

macrumors regular
Oct 26, 2006
116
1
Seattle
I believe that the computer knows when to stop charging the battery, and will not send power to the battery once it gets to like 99% charged, so it shouldnt cause any added wear on the battery to keep it plugged in.
 

projectle

macrumors 6502a
Oct 11, 2005
525
57
I am not usre about how Apple's laptops are designed, but when I was working for HP, we always had our laptops run from the battery at all times and the DC input would keep the battery at a sustained charge, providing conditioning to the current, reducing the likelihood of damage to the system components as well as ensuring that when swapping power sources you did not lose everything that you were working on.

I would assume that Apple is the same way, but of course no guarentees there as I have never actually ripped apart my MBP to see for sure.
 

thewhitehart

macrumors 65816
Jul 9, 2005
1,103
607
The town without George Bailey
It's good to run it off the battery once in a while. Don't keep it plugged in forever. Calibrate it at least once a month, and you'll be fine. To keep capacity at a maximum, when you do use the battery, try to run it from 100% to 0% as often as you can.

Don't make yourself crazy. The battery should be at about 80% capacity after 350 charges and discharges, which is a lot. I had my ibook for a year, and only went through 69 cycles, and the battery was at 94% capacity.
 

WildCowboy

Administrator/Editor
Staff member
Jan 20, 2005
18,490
2,991
Running on AC almost all the time is fine, but yes, calibrate your battery every few months.

Your Mac knows not to charge the battery unless it dips below 95%, so you don't have to worry about constant overcharging.
 

lenojd

macrumors newbie
Nov 17, 2006
5
0
over the last week I have noticed my battery life has dropped to only about 1.5hrs

I have downloaded coconut battery and here are the results.. doesnt appear like anything is worng however the battery capacity is now only 97% is that normal after a short period??
 

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miniguu

macrumors regular
Jun 16, 2005
160
0
over the last week I have noticed my battery life has dropped to only about 1.5hrs

I have downloaded coconut battery and here are the results.. doesnt appear like anything is worng however the battery capacity is now only 97% is that normal after a short period??

Try calibrating the battery (draining it down and then charging it to 100% in one pass).
 
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