Cell phones are usable in most places, but unfortunately chargers are not. If you frequently travel outside the range of a wall outlet or car jack, you know that cell phone battery life is never long enough. Fortunately, it is relatively easy to make a homemade cell phone charger. This small, portable device will allow you to use AA batteries to keep your phone charged no matter how far you stray from an electrical socket.
Take out the screws of your cellphone's charger jack (the end that plugs into the phone) with your screwdriver. If there are no screws, pop the charger jack open with a small knife. The goal is to expose the inside of the jack that contains the positive and negative wires.
Separate the jack from the cord. Do this by cutting the positive wire and then the negative wire. The end product should be the rectangular jack trailed by two short sections of exposed wire.
Solder the exposed wires to the wires of the four-AA battery charger. The exposed cell phone jack will indicate which wire is positive and which is negative. Solder the positive wire from the battery charger to the positive wire of the jack. Then solder the negative wires in the same fashion.
Rescrew or resnap the cover to the cellphone jack.
Insert four AA batteries into the battery charger. Then plug the jack into your phone.
For illustrations, check out the YouTube video in the "references" section below. Be sure the voltage on your battery holder corresponds to the voltage requirements of your phone (for example, a phone that requires 5.6 volts will need a 6-volt battery holder).