Step1 :Cut a piece of the copper sheeting that is about the size of the burner on the stove. Wash your hands so they don’t have any grease or oil on them. Then wa
sh the copper sheet with soap or cleanser to get any oil or grease off of it. Use the sandpaper
or wire brush to thoroughly clean the copper sheeting, so that any sulphide or other light corrosion is removed.
Step 2: Place the cleaned and dried copper sheet on the burner and turn the burner to its highest setting.
Step 3: Cut another sheet of copper about the same size as the first one. Bend both pieces gently, so they will fit into the plastic bottle or jar without touching one another.
Note: The cuprous oxide coating that was facing up on the burner is usually the best side to face outwards in the jar, because it has the smoothest, cleanest surface.
Step4: Attach the two alligator clip leads as shown in the picture, one to the new copper plate, and one to the cuprous oxide coated plate. Connect the lead from the clean copper plate to the positive terminal of the meter. Connect the lead from the cuprous oxide plate to the negative terminal of the meter.
Step 5: Now mix a couple tablespoons of salt into some hot tap water. Stir the saltwater until all the salt is dissolved. Then carefully pour the saltwater into the jar, being careful not to get the clip leads wet. (The saltwater should not completely cover the plates — you should leave about an inch of plate above the water, so you can move the solar cell around without getting the clip leads wet.)
Notice that the meter is reading about 6 microamps of current.
The solar cell is a battery, even in the dark, and will usually show a few microamps of current.