What is the approximate open-circuit voltage per cell in a lead-acid battery?

What is the approximate open-circuit voltage per cell in a lead-acid battery?

• A. 1.8 V
• B. 2.0 V
• C. 2.7 V
• D. 2.1 V

Answer: (D)

Open-circuit voltage per cell is the voltage you measure across a single lead-acid cell when no current is flowing. For this chemistry, the resting potential sits about 2.1 volts per cell. That’s why a six-cell 12-volt battery reads roughly 12.6 volts when fully rested and charged. Values like 2.7 V are too high for a single cell, and 1.8–2.0 V are lower than the typical resting level. So the correct, widely accepted resting per-cell voltage is about 2.1 V.

Open-circuit voltage per cell is the voltage you measure across a single lead-acid cell when no current is flowing. For this chemistry, the resting potential sits about 2.1 volts per cell. That’s why a six-cell 12-volt battery reads roughly 12.6 volts when fully rested and charged. Values like 2.7 V are too high for a single cell, and 1.8–2.0 V are lower than the typical resting level. So the correct, widely accepted resting per-cell voltage is about 2.1 V.