The output voltage of any cell be it chemical, photovoltaic, or thermal is dependant on the materials that make up the cell. So a carbon-zinc cell will produce 1.5 volts regardless of size. It can be a AAA or the size of a tanker truck, it's still 1.5 volts. The size does play into current capacity or the amount of current the cell. Pictured above is a 225 watt solar panel made with 60 solar cells producing 30 volts at 7.5 amps. In this case we wired all 60 cells in series (.5 volts X 60) for a panel to be used with a 24-volt charging system. We could have wired the. PARTS AND MATERIALS 1. Two 6-volt batteries 2. One 9-volt battery Actually, any size batteries will suffice for this experiment, but itis recommended to have at least two different.