Have a used 9v battery from a gadget?You don't need to throw it away.Probably it will have enough voltage to drive a rgb led.You can use this battery to make something really cool for yourself by reading this instructable.
CONTINUE TO READ TO MAKE A REALLY COOL LIGHT
Step 1: Things You Will Require
A rgb led that changes color automatically,a used 9v battery ,9v battery holder and soldering machine.
Step 2: Construction
Open the battery holder and remove the wires.Now solder the negative(longer) electrode of led to the positive connector of holder and the positive(shorter) electrode of led to negative connector of holder carefully seeing that the electrodes don't touch each other.Now close the holder and attach it to a used 9v battery and your disco light will be ready to use(flash)!!!!!!!!
Now You can finish your project here by using it as disco lights or you can continue further with the instructable and make yourself a cool glow ball.
Step 3: Making the Glow Ball
For this you can take a normal crazy or bouncing ball and make a hole in it using a scissor.Remember the hole should be so wide that the led can fit in it.
Step 4: Inserting the Led
Now take the led and fix it inside the hole and connect it to a 9v battery