iphone's battery calibration

Hey there Huynguyen1233,

While there's not a way to 'calibrate' an iPhone battery, we'd like to still help get the most out of it.

Check out the section 'Tips for iOS Devices' in this link: Maximizing Battery Life and Lifespan

Take care.

Way back when, it was best practice to calibrate the battery sensor (not the actual battery) by draining the battery completely then recharging it completely. Apple used to recommend you do this once a month. However, the technology has improved and you no longer need to do this procedure.

For more information, see this great user tip:

When to charge your iPhone or iPad - Apple Community