For Seniors: How to Charge the iPhone 4S Battery
Your first step in getting to work with the iPhone 4S is to make sure that its battery is charged. Your iPhone probably showed up in the box fully charged. Because all batteries run down eventually, one of your first priorities is to know how to recharge your iPhone battery.
Gather your iPhone and its connector cord and power adapter.
Gently plug the USB end (the smaller of the two connectors) of the Dock Connector to USB Cable into the USB Power Adapter.
Note that if you have a hard case for your iPhone remove the phone from it while charging as these cases retain heat which is bad for the phone and case.
Plug the other end of the cord into the cord connector slot on the iPhone.
Unfold the two metal prongs on the power adapter so they extend from it at a 90-degree angle, and then plug the adapter into an electric outlet.
If you buy the Apple iPhone Dock accessory, you can charge your iPhone while it’s resting in the Dock. Just plug the larger connector into the back of the Dock instead of at the bottom of the iPhone.