Solar energy battery, or photovoltaic cell, is a kind of electrical equipment that directly converts light energy into electrical energy through the photovoltaic effect. The photovoltaic effect is a physical and chemical phenomenon. It is a form of photovoltaic cell, which is defined as a device whose electrical characteristics such as current, voltage, or resistance change when exposed to light. Individual solar cell devices can be combined into modules, also called solar panels. Basically, a single junction silicon solar cell can generate a maximum open circuit voltage of about 0.5 to 0.6 volts.

A solar energy battery is described as a photovoltaic cell, regardless of whether its source is sunlight or artificial light. They are used as photodetectors (such as infrared detectors) to detect light or other electromagnetic radiation in the visible range, or to measure light intensity.

The operation of a solar energy battery requires three basic attributes:
The absorption of light produces electron-hole pairs or excitons.
Separation of opposite types of charge carriers.
These carriers are separately extracted to the external circuit.

In contrast, solar collectors provide heat by absorbing sunlight for direct heating or indirect power generation. On the other hand, "photoelectric decomposition battery" (photoelectrochemical cell) refers to a solar energy battery, or a device that uses only solar light to directly decompose water into hydrogen and oxygen.