Source: Unicorn Electronics
Wires are used to connect the components together. Since the currents involved are very
upon the installation environment, you don't want to use wires that are too thin, for they
waterproof or underground-rated wires that are meant to be used in landscape lighting
For indoor use, you can keep things simple. If you're using a battery charger, you can
simply use the wires that it came with.
The electrodes are electrically-conducting materials, which are used to make contact with
the soil. While most metals can be used to make a reliable electrical connection to the
and susceptibility to leaching or corrosion are factors that should be considered. In fact,
electrodes need not always be metal; they can also be made of conductive, yet inert,
solid and liquid conductors.
For the sake of this introductory topic, you can use just about any commonly available
metal as your electrodes, such as a steel bolts or iron nails.