calibrating battery

[johnchristy44]

Hi guys

So i have my new macboor air plugged in all the time. Meaning whenever i switch on my laptop i will on my power adaptor. I know there are so many articles about how to use mac with/without battery power etc. So i thought of calibrating my battery twice a month.

Right now my battery is at 100% fully charged/plugged in. So all i have to do is, remove the charger, use up my battery up to lets say 15-20% and then plugin the charger and charge up to 100% again and leave the plug on after that. Is that correct? really simple stuff but i read somewhere that after draining the battery i need to power off my laptop for like 5+ hours. Im not sure if its correct or not..

Thanks

 

[MacInWin]

The only reason for draining the battery is to calibrate the reporting process. It does no good for the battery itself. Lithium batteries want to stay in the 60-80% range for longest life. Deep discharges (below 40%) are hard on the battery.

So, what to do? Do what I do, leave it on mains and don't bother with calibration of the reporting process. When/if you need to use the battery, go ahead and do so, but don't do it deliberately for any reason. My MBP is on mains probably 95% of the time.

If you do a search of this forum there are a couple of longish posts on the chemistry/physics of lithium batteries. There are many factors that affect potential life, but for an Apple laptop, using it the way you are the battery will last much longer than the computer itself.

If you decide to go ahead with calibration runs, you don't need to wait. Deplete the battery and then put it on mains. No need to wait.

But just don't do it. No need.

 

[ferrarr]

Here is Apple's info on their batteries, Batteries - Apple

 

[SWLinPHX]

For calibrating you charge it to 100%, run it on battery until after the Low Battery warning and then it shuts off on its own. Then you leave it discharged and unplugged for at least 5 hours, then plug it in again and charge it fully.But yes, this only calibrates for more accurate readout; it doesn't prolong the battery life. I too leave mine plugged in all the time. I use my 17" MacBook Pro's as fixed "desktop computers" except bedside (so portable but with the biggest 17" displays). I have a 13" for portability for quick runs, thought I take my 17" for trips/travel.