Want a great use for you old phones sitting around? Sure you do. I have the perfect solution. Turn them into rechargeable battery packs.

Parts and Tools:

1. Screw driver
2. Soldering Iron
3. Multi-meter
4. Solder
5. Flux
6. Wire cutters
7. Knife or razor

Note: A battery with a protection circuit is advisable to make sure you don't discharge the battery too much.

Step 1: Find Charging Terminals

1. Take the phone battery back off
2. Take out the battery
3. Plug the charger into the phone
4. Take a multi-meter and find the positive and negative terminals

• Most phones have 2 to 4 terminals that connect to the battery and are clearly labeled.
• Most likely you will have a +, -, and T. The + is positive, the - is Negative, and the T is a temperature terminal

Step 2: Solder

Solder your wires, or plugs, onto the terminals that you found to be positive and negative. try to solder to the outside surface of the terminal (the one that makes contact with the battery). You may have to take a knife or razor and carve some of the plastic away in order to allow the battery to fit while the wires are soldered.

Step 3: Replace Battery and Back

Put battery back into the phone and use your multi-meter to test weather or not you are receiving voltage which means you are receiving current through the wires. If yes, then plug the phone charger in and see if you are able to charge the phone.

Locate where the wires are coming out of the phone and cut or drill an appropriate hole in the battery back to allow for the wires to be accessed.

Step 4: Test

Test and see if you are still getting voltage and current.

Step 5: Thoughts

This is a great little mod because it allows you to use a phone that you otherwise would not. It is great for running an Arduino mini or other small item. The best part is that it has alarm functionality, a clock, and a great battery bar. I have done many phones and have had great success.