I’ve seen some confusion on the Internerd about batteries and recalibration. Maybe this will help.
As you use the lithium ion battery in your phone or computer, charging and discharging it, it gradually loses it’s ability to store electricity. Most notebook and phone manufacturers have a procedure to recalibrate and take the decreased run time into account. Most of them are variations of charge it, let it run down completely and then charge it again.
The recalibration procedure will not and can not restore your battery to its original capacity. All it does is let your device more accurately estimate the charge in left in the battery. Batteries, even rechargeable ones, get used up and have to be replaced eventually.
I figure a lithium ion battery has 300 or so charge/discharge cycles in it before the available run time becomes a problem for me so I usually replace them once a year.
just how are you supposed to replace the battery in an iPhone?
Open the phone and replace the battery. Or send it somewhere. It’s not as easy as opening a battery door but it’s not impossible either.
This sounds about right. My Blackberry is just a bit under a year old and I noticed a marked drop off in battery life. I got a replacement that will hold me until upgrade time next year.