A solar cell panel, solar electric panel, photo-voltaic (PV) module or solar panel is an assembly of photo-voltaic cells mounted in a framework for installation. Solar panels use sunlight as a source of energy to generate direct current electricity. A collection of PV modules is called a PV panel, and a system of PV panels is called an array. Arrays of a photovoltaic system supply solar electricity to electrical equipment. Photovoltaic modules use light energy (photons) from the Sun to generate electricity through the photovoltaic effect. Most modules use wafer-based crystalline silicon cells or thin-film cells. The structural (load carrying) member of a module can be either the top layer or the back layer. Cells must be protected from mechanical damage and moisture. Most modules are rigid, but semi-flexible ones based on thin-film cells are also available. The cells are usually connected electrically in series, one to another to the desired voltage, and then in parallel to increase current. The power (in watts) of the module is the mathematical product of the voltage (in volts) and the current (in amperes) of the module. The manufacturing specifications on solar panels are obtained under standard condition, which is not the real operating condition the solar panels are exposed to on the installation site.

The Odeyo solar power station in France is the first solar power station in the world to realize solar power generation. Although the power generation was only 64 kilowatts at the time, it laid the foundation for the later research and design of solar power plants. The solar power generation system mainly includes: solar cell components, controllers, batteries, inverters, loads, etc. Among them, the solar cell components and batteries are the power supply system, the controller and the inverter are the control and protection system, and the load is the system terminal. The solar cell module is the core part of the power generation system. Its function is to directly convert the radiant energy of the sun into direct current, which is used by the load or stored in the battery for backup. Generally, according to the needs of users, several solar panels are connected in a certain way to form a solar cell array (array), and then matched with appropriate brackets and junction boxes to form a solar cell module. In the solar power generation system, the basic function of the charge controller is to provide the best charging current and voltage for the battery, charge the battery quickly, smoothly and efficiently, reduce the loss during the charging process, and prolong the service life of the battery as much as possible. It also protects the battery from overcharging and overdischarging. The advanced controller can simultaneously record and display various important data of the system, such as charging current, voltage and so on.

An electric vehicle charger is a device specially designed to charge the vehicle battery of an electric vehicle. It is a power conversion device with specific functions used to charge the battery. Electric vehicle chargers can be divided into DC chargers and AC chargers. The DC charger refers to the charger that uses the DC charging mode to charge the electric vehicle power battery assembly. The DC charging mode is a mode in which the controllable DC power output from the charger directly charges the power battery assembly. The AC charger refers to the portable EV charger that uses the AC charging mode to charge the electric vehicle power battery assembly. The AC charging mode is a mode in which a three-phase or single-phase AC power supply provides charging power to an electric vehicle. The characteristics of the AC charging mode are: the charger is a vehicle-mounted system. The charger adapts to the battery type: the charger can charge at least one of the following three types of power batteries: lithium-ion battery, lead-acid battery, and nickel-metal hydride battery.