Battery Question

I've never seen an Apple notebook running OS X that told the correct battery life when plugged in. Even my 2 week old MacBook Pro says its charged at 98%. Sometimes it says 99% even when its "charged". I don't think its a huge issue. What you want to watch for is how long you can go on battery. Or, check to see if it goes from something like 25% to 10%, to 0% with in a very short period of time. That would indicate a problem with the battery. Remember that the battery is considered as a "wearable" item so even if you have AppleCare they may not replace it after the original warranty.

I've had a 17" PowerBook G4 and 500 MHz iBook G3 that both did the same thing as well. It would show charged at 98% or whatever. I would also assume that batteries aren't always going to charge back up to 100% all the time either.

 

That 95% is when the battery discharges, It is considered full between 100-95%. Just pull the plug for a few minutes to discharge the battery a bit.

The more you charge the battery the more its going to drain its life cycle and its ability to keep it at a full charge.

 

The best thing to do is when using the battery, let it run down to somewhere around 3% left and then charge it backup. The one thing a lot of people forget to do with any notebook (Apple, Dell, Gateway, Sony, etc) is to condition the battery. To do that, run it down to nearly dead (3% for example) and then charge it back up. If you do that then it will get used to using the entire battery.

A lot of people also only use the battery part of the way all the time and then charge it back up. So say for example you only let the battery get down to 30% left and then plug it in all the time. If you always do that then the battery will get used to only working under 30% is left and then the battery life will plummet to 0% and the notebook will go to sleep until you plug it back in.

 

Download this program, http://www.coconut-flavour.com/coconutbattery/

 

Per my coconutBattery 2.5.1 on my MB:

Current Battery Charge: 5277 mAh
Maximum Battery Charge: 5346 mAh
98% [MB itself says 99%]

Current Battery Capacity: 5346 mAh
Original Battery Capacity: 5200 mAh
100%

Battery Loadcycles: 13
Age of Mac: 2 months
Charger connected: Yes
Battery is charging: No

Interesting that when I use coconutBattery, my MB fan runs faster as of course the temp rises... And it appears that coconutBattery is doing this via tapping into the "ioreg" to collect the data that it is then displaying.

 

mine sometimes will get stuck at 99 and then i reboot and it says 100.

 

I've heard that it only charges up to 95 - 99% in order to not 'over charge' the battery.

I've stopped worrying about it. I deleted CoconutBattery because it was driving me nuts.