How to calibrate Late 2010 MacBook Air battery?

How can I correctly calibrate the battery of the Late 2010 MacBook Air battery? The Apple support site says that I should use the laptop until it turns off by itself, and then I should shut it down before charging it. But how can I turn it off when I cannot turn the MacBook Air back on to turn it off during critical battery levels? I don't want to wait 5 hours before the battery is totally drained during sleep before I can charge it.

 

Run the computer until it turns itself off. I would wait another 20 mins or so to ensure the battery is cool, plug in the charger and allow to fully charge until its at 100% before removing the charger.

 

I don't think it turns itself off. One time it was playing a video and the battery went flat. The screen went out but the audio kept going until I plug the power in, waked the laptop and paused the video.

 

^ Correct. You have to discharge the battery to the point of forcing the laptop to sleep, then leaving it uncharged for at least 5 hours to run down the battery completely. Then you charge it fully.

See here: Apple Portables: Calibrating your computer's battery for best performance

 

it will turn itself off... it writes a save state to the dive and shuts down. You didn't wait long enough. Let it keep going until it is actually off... then wait another half an hour... plug in power, do not turn it on... leave it plugged in until its done charging (when the light turns back green its no longer charging)