Calibrate the battery of the iPhone 6S

SoCalDude,

As stated in the User Tip referenced by ManSinha:

The worst thing you can do is drain the battery to 0%, then not charge it immediately. After it reaches zero and shuts off there's a small amount of energy left, but if you leave it uncharged for long it WILL go flat and kill the battery. So if it reaches zero, charge it soon (within hours). And never leave a phone unused for weeks or months on end without periodically recharging it.

For that reason, I would advise limiting such optimizing techniques to once or twice a year.

I would start here...http://www.apple.com/batteries/why-lithium-ion/ and then once you have read that and become familiar with the expectations of your battery, go through http://www.apple.com/batteries/maximizing-performance/.

I went ahead and read through the other link which was posted by ManSinha, and for the most part, it is true. The one thing I would add though is that his explanation of "killing the battery" is a little exaggerated. Should you go without charging your battery for a prolonged amount of time, it isn't healthy for the battery, but it won't kill it outright. You will be likely to have a reduction in the number of cycles you can expect out of your battery by doing this. That much is certain. All in all, letting your battery die and remain dead is not recommended, but don't freak out about it.

You do not need to "optimize" your battery at all. Lithium-Ion batteries do not require the refresh cycles of Ni-Cds or Ni-Mh. You can charge them whenever you wish. The only risk is leaving a discharged battery in that state for a long time. If in doubt, there is a very good App on the Store called Battery Life and it is free. It will test the state of your battery and give you a good report.

Optimizing iOS Battery Usage - Lawrence Finch