This markerlight token is made from an LED, a 2032 battery, foam core board, and some glue. If you have seen this before, its quite possible you have. I am just wrapping up these LED Throwies in a different package.
Lets start with the components. On the left are the batteries you need. They are 2032 LI 3V Batteries. If you buy them from a local store expect to pay around $2.50 per battery. You can get them for a lot cheaper online if you look around. [See the Throwies link above]
On the right is a LED. If you have never used one before, its not too hard in this case. Just know that one lead is called the anode and will connect to the positive side of the battery. The other lead is the cathode and will connect to the negative side of the battery. The cathode lead is usually shorter and the base of the LED is flat where the cathode connects to the LED.
The easiest place to get LED's is Radio Shack, but you can find them much cheaper online.
Its time to start the construction. Cut a circle the size of the standard unit base out of the foam core board. Punch a small hole through the base and then score a line into the foam, but do not cut all the way through the foam. This hole and line will guide the leads of the LED to the battery.
Now, stick the cathode of the LED through the hole and run the anode of the LED through the scored channel so it points off to the side as in the picture below.
Make sure that the leads of the LED do not touch each other!
Flip the markerlight over and coil up the cathode as shown in the picture. This is to ensure a better connection to the battery.
Next place the battery so the negative side makes contact with the LED cathode. You need to glue the battery to the place, but BE VERY CAREFUL. If you choose to use hot glue as I did, only apply a little glue at a time and allow several minutes in between glue applications. Heating up batteries can be VERY DANGEROUS, ESPECIALLY LITHIUM ION BATTERIES. If you INJURE/KILL anyone in the process it's your fault and your fault alone.
Once the glue has dried, wrap the anode of the LED around the outside edge and touch it to the positive end of the battery. If you did everything right, the LED will light up. If it didn't light up, then you messed something up.
Once it is time for battle, go ahead and tape the anode of the LED to positive end of the battery so the light stays lit. These should run for close to 200 hours.
You may want to try and place some sort of translucent cover over the LED or decorate the base to give it a different look.