Light emitting diodes (LEDs) require little power and can prove useful in many tasks, from large signs to small model sets. Many lights you can obtain from a model shop have wires preconnected for you to hook up to a battery. A 9-volt battery is the best to use with these lights because you can easily connect it through an insulated battery strap with the right terminal. The project simply involves connecting the light wires to the strap wires.
Twist all the red wires attached to the LED set to the single red wire connected to a battery strap. You should have one red wire for each light, which functions as the power wire.
Connect all black wires on the lights to the black wire on the strap using the same twisting method. This step completes the ground connection for all the lights.
Wrap electrical tape around the red wire connections and then the black ones, taking care that none of the reds touch the blacks. (Soldering is another more permanent method.)
Connect the snap cap on the battery strap to your 9-volt battery; the cap has two clamps specifically designed for this battery's positive and negative terminals. The lights should come on once you connect the battery.
To solder the wires, touch the end of a solder spool to the spot where the wires are twisted together and then heat the wire with a soldering iron, taking care that the iron doesn't touch the solder. Cover the connected wires with the tape after the solder cools.