A Simple Solar Conversion
of an RC Model Car
by Chuck Wright

A quick, easy, and fun way to build a model solar car is to add a solar panel to an inexpensive, commercially-available radio-controlled car. We recommend wiring it so that the solar panel charges the existing battery, so that you can run it in the shade (although you might argue that this makes it no longer solar powered, remember that the battery is just a storage device...as long as you are charging it from the solar panel, it is solar powered!).

To make the conversion, you will need to obtain a car, solar panels, a switch, a silicon rectifier, some wire, and will need to do some soldering.

Car - You can find cheap RC cars at discount stores. You will need to consider the voltage, which needs to be a volt or two less than whatever you can get from your solar panel(s). In our conversions, we have used 2, 3-volt panels wired in series, and a 4.8 volt car.

Solar Panel - A convenient solar panel to use is the one sold for use in the Solar Sprint car races (we aren’t building a Solar Sprint car here; this is just a good panel), available from Pitsco (http://www.pitsco.com), or SBT Automation (http://www.lore.net/~sbt, or 210-698-7109). The panels put out about 3 volts (6 cells in series) each.

Silicon Rectifier - a 1N4001 works well. If you can find a Schottky rectifier rated at a couple of amps, thats even better (less loss through the rectifier).

Here is a schematic showing a good way to wire it:

After your car is finished (and working!), cut out the following banner and attach it to the car!

Texas Solar Energy Society
http://www.txses.org