Most cell phone batteries produce 3.7 volts and are lithium-based. It's likely your remote control (RC) airplane needs higher voltage to operate, so you may need to wire a couple of cell phone batteries in series to get to the correct voltage. The advantage of using cell phone batteries is that they are light in weight, which is an important factor when you fly RC airplanes.
Determine the voltage of your RC airplane engine. It will be marked on a label on the engine. For example, if it needs about 8 volts then you need two cell phone batteries in your RC airplane, as each battery produces 3.7 volts. You don’t need to have the exact voltage, as long as it’s close. If, like many people, you have a couple of old cell phones around, charge the cell phone batteries and use them. If you need to buy cell phone batteries, all cell phone stores sell them.
Wire the cell phone batteries in series, if you’re using more than one. Cut two 2-inch strips of AWG 18-gauge wire, using a knife. Remove about 1/4-inch of insulation from the ends of the wire strips, using wire strippers.
Connect the end of a short wire strip to the negative terminal of the cell phone battery. You need to use a thin strip of insulating tape, as the terminals are close to each other. Connect the opposite end to the positive terminal of the second battery using the same method. Wrap some tape around the batteries to keep them together.
Cut two additional strips of AWG 18-gauge wire, using a knife. The strips need to be long enough to connect between the cell phone battery and the RC airplane engine. Remove about 1/4-inch of insulation from the ends of the wire strips, using wire strippers.
Connect the end of one wire strip to the positive terminal of the first cell phone battery, using a thin strip of tape. The other end connects to your RC airplane’s engine. Connect the end of the second wire strip to the negative terminal of either the first or second cell phone battery, depending on whether you are using one or two batteries in your pack. The other end connects to your RC airplane’s engine.
