Open-circuit voltage

Open-circuit voltage (abbreviated as OCV or VOC) is the difference of electrical potential between two terminals of an electronic device when disconnected from any circuit.

The open-circuit voltages of batteries and solar cells are often quoted under particular conditions (state-of-charge, illumination, temperature, etc.).

The potential difference mentioned for batteries and cells is usually the open-circuit voltage.

The value of the open-circuit voltage of a transducer equals its electromotive force (emf), which is the maximum potential difference it can produce when not providing current.

Use Ohm’s law with that current to find the potential drop across the resistance C. Note that since no current is flowing through resistor B, there is no potential drop across it, so it does not affect the open-circuit voltage.

Definition of open-circuit voltage. The box is any two-terminal device, such as a battery or solar cell. The two terminals are not connected to anything (an open circuit), so no current can flow into or out of either terminal. The voltage v oc between the terminals is the open-circuit voltage of the device.
Black curve: The highest possible open-circuit voltage of a solar cell in the Shockley-Queisser model under unconcentrated sunlight, as a function of the semiconductor bandgap . The red dotted line shows that this voltage is always smaller than the bandgap voltage.
Given Circuit
Given Circuit
Modified Circuit
Modified Circuit