How to charge iphone 5 correctly

Question

Hi everyone,
So Apple says to do a full cycle charge once a month (charge iphone from 0% to 100% and then do a reset) right?!
But during everyday use should I charge the phone for bit during the day? Or just charge every night before going to bed?
When the 20% alert shows you must charge the iphone to avoid a complete cycle charge?
Any suggestions?
Thank you

Answer 1

The purpose of the full cycle charge is to recalibrate the battery gauge. Lithium chemistry batteries are notoriously hard to manage, because their voltage does not drop linearly with state of charge, as most other secondary cells do. So the battery gauge monitors battery charge going in and battery drain going out, and computes the remaining life from this. But the battery's capacity drops with age, and the calculation isn't perfect. So after a while the gauge no longer knows what the state of charge actually is. The most obvious symptom of this is when the phone suddenly shuts off well above 1% remaining. When you run the battery all the way down, then charge fully, the charging circuit in the phone can re-establish the end points.
Anyway, the answer to your question is charge it whenever you want, except that you should periodically run it all the way down, then fully charge it (once a month, as Apple suggests). But not every day. According to Apple this does not affect the total lifetime of the battery.
Oh, one other point. The iPhone will not let you deep discharge the battery. When it shuts off at 1% there is still significant charge left. It's unusable charge, except to keep iOS alive. If you fly a plane there are 2 numbers you need to know - total fuel capacity, and useable fuel capacity, which is always lower. Same with Lithium batteries in electronics.