For Seniors: Extend the Battery Life of Your iPhone 4S
The much-touted battery life of the iPhone 4S is a wonderful feature, but you can do some things to extend it even further. Here are a few tips to consider:
Keep tabs on remaining battery life. You can estimate the amount of remaining battery life by looking at the Battery icon on the far-right end of the Status bar, at the top of your screen.
Use standard accessories to charge your iPhone most effectively. When connected to a modern Mac or Windows computer for charging, the iPhone can slowly charge; however, the most effective way to charge your iPhone is to plug it into the wall outlet using the Dock Connector to USB Cable and the 10W USB Power Adapter that come with your iPhone.
The fastest way to charge the iPhone is to turn it off while charging it.
The Battery icon on the Status bar lets you know when the charging is complete.
Your iPhone battery is sealed in the unit, so you can’t replace it, as you can with many laptops or cellphone batteries. If the battery is out of warranty, you have to fork over about $79 to get a new one.