To increase voltage, fuel cells can be stacked or what?

• A. Lowering temperature
• B. Increasing gas pressure
• C. Using larger electrodes
• D. Stacking multiple cells

Answer: (D)

To raise the overall voltage, you connect several cells in series to form a stack. In a series arrangement, the voltages of each cell add up, so the total stack voltage increases with the number of cells, while the current capability remains similar to a single cell. This is why stacking multiple cells is the standard method to achieve higher voltage.

Lowering temperature slows the reactions and can reduce voltage under load. Increasing gas pressure mainly affects the rate of reactant delivery and the current, not the voltage per cell. Using larger electrodes changes how much current you can draw by reducing resistance, but it doesn’t increase the voltage of the cell itself.