OCV

OCV stands for Open Circuit Voltage in the fields of electrochemistry and energy storage. It describes the potential difference between the terminals of a cell, battery, or stack when no current is drawn. In this condition, the measured voltage reflects the thermodynamic equilibrium potential of the electrode materials and electrolyte, unaltered by voltage drops that occur under load. Measuring OCV requires a high-impedance voltmeter to avoid discharging the cell during the measurement.

OCV is commonly used to infer state of charge (SOC) for many battery chemistries. The relationship between OCV and SOC is chemistry-specific and can be history-dependent, with relaxation effects after charging or resting causing the voltage to change before stabilizing.

In battery management and modeling, OCV is often paired with SOC estimation methods. Because OCV-SOC curves vary with temperature, aging, and previous operating conditions, accurate use requires chemistry-specific data and control of measurement conditions.

Open-circuit voltage is also a term used in photovoltaics to describe the maximum voltage of a solar cell under no-load conditions (often denoted Voc). In solar devices, Voc is influenced by temperature and recombination losses and serves as an indicator of material quality and device performance.

Other uses: OCV is an acronym that can refer to various organizations, concepts, or terms in different domains, and its precise meaning depends on context. This article focuses on the technical meaning related to open-circuit voltage in electrochemistry and photovoltaics.