The multi-color pathway lights we used have a small PCB that controls the battery charging function as well as the "random" color changing function of the LED. You can use clear pathway lights as well - whether to use color or clear is a personal preference. All the "tech" is provided by the pathway light. What we are going to do is to disassemble the light, relocate the LED to an ornamental glass ball and attach a wire hanger to the solar module so that the solar light can be hung from tree.
Step 1: Bits and Pieces
All told, cost for a single light will be roughly $5 each which the major cost from the pathway light. The balls work out to about $0.80 each.
Tools you will need are drill with 1/16" and 1/4" drill bits, pliers, side cutters, hot glue gun, sharp knife, Phillips screwdriver and a soldering iron.
Step 2: Making the Solar Module
Unscrew the screws on the bottom of the solar module to expose the battery, LED and PCB. For these lights, the PCB was held in place with a melted plastic rivet and hot glue. It was easy to remove with a gentle upward pull. There is a variation on the PCB color and mounting even for the same solar lights. Seemed odd but it would appear that the internals come from different factories - some have green PCBs others are brown. Since we made up 6 lights in one day some pictures will have green, some brown.... just depends on which pictures were taken when!
Remove the LED from the PCB. The easiest way is to first mark one leg of the LED with a black sharpie, and then mark the same hole on the PCB with a black sharpie, then cut the legs of the LED to free the LED from the board. If you have a solder sucker, you can unsolder the LED from the board. The goal is to free the LED with long enough legs for you to solder wires to the LED.
Solder the twisted pair to the PCB. Tie a knot in the wire so that the ball will eventually hang putting strain on the know and not on the solder connections. This is called strain-relief. Basically allow two inches of wire between the PCB and the knot. Do not pull the know tight.
Use a 1/16 drill (or larger if your hanger wire is thicker) to make holes on either side of the solar panel. Then form your wire hanger and press through the holes. Bend small feet on the back side and then hot glue them. Add a little hot glue to the top as well to prevent water from running into your solar module.
Feed the wire through the hole in the base plate and then use hot glue to secure the PCB to the base plate. You can now re attach the base plate and fasten the 3 screws that you removed earlier.
Solder the LED to the far end of the wire. Use electrical insulation tape or heatshrink to make sure that the negative and positive leads do not touch each other or your LED will not light up. It is important to connect your LED the same way as you marked when you cut it free. LED is polarity sensitive and will only work in one electrical orientation.
Step 3: Making the Ball
The glass balls come with a flimsy silver cap. Enlarge the hole in the top with a 1/4" drill bit. Work carefully because it is easy to unintentionally destroy the cap. The hole needs to be big enough for the LED to go through it.
Trim the wire clips that hold the cap onto the ball shorter. This makes it harder to assemble the ball but avoids the clip showing a shadow down the surface of the ball when it is illuminated.
Feed the LED through the hole so that the wire side of the LED is about 1/4" into the silver cap and then hot glue the back end. This will seal water out and provide support for the wires.
Finally, once the glass ball has dried, run a bead of hot glue around the top rim of the glass ball and quickly install the cap/LED assembly to complete the ball. You need to work quickly before the hot glue sets. The glue will help support the clip function of keeping the cap and ball together. In the last picture with the unpainted ball, you can see how everything should look after this final assembly step.
Step 4: Hanging Them Up
Since we had a lot of pathway light scraps, we glued two of the cones back to back to make a hanging pendant as shown in the last picture.
And that is that! Enjoy the "free energy" light show.