Looking for a consistent answer about battery calibration

This forum is full of questions about battery calibration. The thing is, that either I'm blind or one answers contradicts others.

In particular:

1. 
   

   For example forums says, that battery should be discharged to an absolute minimum. If you can power-on your phone, you should keep turning it on until battery is discharged so badly, that you can't turn it on. Sounds creepy and is in complete opposition to Lie Ryan, who says, that "a full discharge is never beneficial to LiON battery capacity".

   
   


2. 
   

   Again, forums says, that after full discharge and full charge, calibration process is completed, while Logas claims, that it needs a nearly-full discharge, full charge and again running battery fully flat.

   
   


3. 
   
   

   Citing forums third time, he says, that battery formatting process should be undertaken only in rare, quite critical situations, when battery behavior became some sort of strange, while Logas says, that this should be done every 30-90 days.

   
   


4. 
   

   All of them says about battery calibration at all, while Matthew Read says, that Android handles battery calibration and therfore (I assume) user should not do nothing about this.

   
   


5. 
   

   Found some answers and comments saying, that both battery calibration and regular charging process should be done on turned-off phone, while others says that it is unusual with modern mobile systems to turn off phone completely very often.

   
   

So, can someone provide a consistent answer on these matters? Does the battery used in Android device require calibration at all? If yes, then how often, and what steps should be done to achieve this? Do I really have to run phone until it is really, really flat and do I have to charge it, while it is off?

Answer

There are slightly different opinions around on this topic. To fully understand the issue, one needs to first understand how LiIo batteries work (which goes a little too far for our site, so please read details on Wikipedia).

1. Lie Ryan is absolutely right: LiIo batteries don't take it well to be fully discharged.


2. It shouldn't be done too often. I'm not sure what a double-take should improve here.


3. Usually there's no need to do that "explicitly". If you think of how often you end up with an empty batterie (as it doesn't last long enough), calibration is already done as a side-effect (if you then fully charge). It's widely agreed that it should not be done more often than once in 60..90 days, so Logas might have mistaken the term.


4. See previous point :) I never saw reason to calibrate any of my devices' battery, though.


5. It certainly cannot hurt to do it with the device turned off, as then it's not being charged and discharged at the same time. I doubt it's really necessary, but it does no harm :)