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Battery never reaches 100% after charging

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THX1139

THX1139

macrumors 68000
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Mar 4, 2006
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I have a unibody Macbook Pro that is less than two weeks old. I've gone through a couple of battery charge cycles. When I first got it I let the battery drain down to zero and then let it stay that way for about 5 hours before plugging it back in. Once I plugged it in, I let it charge overnight.

Today, I noticed that my MBP shows the battery level at 99% after being plugged in all day. I'm not terribly concerned but I'm curious as to why the level is not at 100%. Is this normal?
 
THX1139 said:
I have a unibody Macbook Pro that is less than two weeks old. I've gone through a couple of battery charge cycles. When I first got it I let the battery drain down to zero and then let it stay that way for about 5 hours before plugging it back in. Once I plugged it in, I let it charge overnight.

Today, I noticed that my MBP shows the battery level at 99% after being plugged in all day. I'm not terribly concerned but I'm curious as to why the level is not at 100%. Is this normal?
Click to expand...

Please be warned or be aware and maybe take it as a caution?
Over draining your battery can cause it to degrade, thus hold less charge and lose it's ultimate performance level. In some cases the cell will malfunction entirely and die, best to keep the electrons moving.

Batteries hate being at 0% and 100%, it's better for it to be at 95~97%
 
I noticed that as well with my MBP 2.5GHz after I got a new battery, but charged it up overnight and it ended up charging an additional 25mAh from the original fully charged mAh (mAh = MilliAmp Hour, or the amount of power a particular battery holds)...
 
UltraNEO* said:
Please be warned or be aware and maybe take it as a caution?
Over draining your battery can cause it to degrade, thus hold less charge and lose it's ultimate performance level. In some cases the cell will malfunction entirely and die, best to keep the electrons moving.

Batteries hate being at 0% and 100%, it's better for it to be at 95~97%
Click to expand...

Interesting, I was told by the guy who sold it to me (at my college bookstore) that I should take in home and "condition" the battery overnight before using it on a regular basis. Now that I've done that, I don't plan to do it again unless the battery starts to fail.
 
THX1139 said:
Interesting, I was told by the guy who sold it to me (at my college bookstore) that I should take in home and "condition" the battery overnight before using it on a regular basis. Now that I've done that, I don't plan to do it again unless the battery starts to fail.
Click to expand...
You should calibrate your battery about once a month.
http://support.apple.com/kb/HT1490
http://www.apple.com/batteries/notebooks.html

And I wouldn't take any technical advice from a bookstore sales clerk.
 
Um, I have an O2 phone and it has the same issue. When I first got it, 100% would always show when fully charged. Then for about six months the maximum it would get to is 99%. Then recently it has been fluctuating between both - AND if it is at 100% and disconnect it, within about 5 minutes (no use) it drops to 99%. Thus I think like ggj said - it must be quite normal for it to fluctuate.

Having said that my 12" PB G4 with the new battery from the recall only gets to 89% now and last only 30minutes or so. Oh well - my wife users it pretty much as a desktop now anyway!!! :eek:
 
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