The total no-load voltage of the 12-cell lead-acid battery (2.1 V per cell) is:

The total no-load voltage of the 12-cell lead-acid battery (2.1 V per cell) is:

• A. 12.6 V
• B. 24 V
• C. 50.4 V
• D. 25.2 V

Answer: (D)

When cells are connected in series, the total no-load voltage is simply the sum of each cell’s voltage. A lead-acid cell sits at about 2.1 volts when it’s not delivering current, so 12 of them in series gives 12 × 2.1 = 25.2 volts. The other numbers correspond to different cell counts: 12.6 V would come from 6 cells (6 × 2.1), and 50.4 V would come from 24 cells (24 × 2.1). So 25.2 V is the correct total for a 12-cell stack. Remember, no-load voltage means no current is drawn, so it’s simply the sum of the cell voltages; under load the voltage would drop a bit due to internal resistance.

When cells are connected in series, the total no-load voltage is simply the sum of each cell’s voltage. A lead-acid cell sits at about 2.1 volts when it’s not delivering current, so 12 of them in series gives 12 × 2.1 = 25.2 volts. The other numbers correspond to different cell counts: 12.6 V would come from 6 cells (6 × 2.1), and 50.4 V would come from 24 cells (24 × 2.1). So 25.2 V is the correct total for a 12-cell stack. Remember, no-load voltage means no current is drawn, so it’s simply the sum of the cell voltages; under load the voltage would drop a bit due to internal resistance.