How an energy storage power supply works depends on its specific type and technology. The following is a brief description of the operating principle of several common types of energy storage power supplies:

1. Electrochemical energy storage: Electrochemical energy storage power supplies, such as lithium-ion batteries and lead-acid batteries, work on the basis of chemical reactions. When charging, current passes through the battery, converting electrical energy into chemical energy, moving and storing ions between the positive and negative electrodes. When it is necessary to release electrical energy, the ions return to their original chemical state and the chemical energy is converted into electrical energy.

2. Mechanical energy storage: Mechanical energy storage power supplies work by converting electrical energy into kinetic or positional energy of an object. For example, the hydraulic energy storage system will be used to compress the liquid when charging the electrical energy, stored as high-pressure liquid energy; when the need to release the electrical energy, by releasing the pressure to promote mechanical movement, the stored energy into mechanical energy.

3. Magnetic energy storage: Magnetic energy storage power supply uses the energy of magnetic field for storage and release. The magnetic field is generated by transmitting charge in the electric current. When energy needs to be stored, the electric current generates a magnetic field in the coil and stores the energy as magnetic field energy; when energy needs to be released, the electric current stops and the magnetic field collapses, releasing the stored energy.

4. Chemical energy storage: Chemical energy storage power sources store and release energy through chemical reactions. For example, a fuel cell chemically reacts fuel (e.g., hydrogen) and oxygen to produce electricity and water. When electrical energy is needed, the fuel and oxygen are fed into the fuel cell and the reaction takes place again, producing electrical energy.

These are just brief descriptions of how energy storage power supplies work, and many different technologies and methods may be used in practical applications. Based on different working principles, energy storage power supplies can provide different characteristics such as energy density, cycle life, charging and discharging speeds, and cost effectiveness to meet the needs of different applications.