Glossary
Terminal Voltage
The voltage that can be measured between the two terminals of a battery.
Each battery has an internal resistance. The terminal voltage is the voltage that is actually available after deducting this resistance. For a battery with a nominal voltage of 12 V this should be 12.72 V. If you measure the voltage at the terminal poles and if this value deviates significantly from this value, conclusions can be drawn about the condition of a battery.