The name of the valve-regulated lead-acid battery is Valve Regulated Lead Battery (VRLA battery for short), which is characterized by no need to add acid and water for maintenance, a sealed structure, and a one-way exhaust valve (also called a safety valve).

　　a. Discharge time rate

　　Under certain discharge conditions, the length of time from discharge to the final voltage is called the discharge time rate. According to the IEC standard, the discharge time rate has 20, 10, 5, 3, 1, 0.5 hour rates, which are expressed as: 20Hr, 10Hr, 5Hr, 3Hr, 2Hr, 1Hr, 0.5Hr, etc.

　　b. End of discharge voltage

　　At 25°C ambient temperature, discharge to the lowest voltage that can be used normally at a certain discharge time rate, which is called the discharge termination voltage. Most lead-acid batteries stipulate that the end voltage at 10Hr discharge (25°C) is 1.8V/pc.

　　c. Rated capacity.

　　At 25°C ambient temperature, discharge the current at a rate of 10 hours to the capacity that the final voltage can reach. The 10-hour rate rated capacity is represented by C10. The current value at the 10-hour rate is C10/10.

　　d. Actual capacity

　　The amount of electricity that a lead-acid battery can output under certain conditions. It is equal to the product of the discharge current and the discharge time, and the unit is Ah.

　　e. Battery internal resistance

　　Refers to the impedance presented by the battery during discharge, which includes ohmic internal resistance and polarization internal resistance. The internal resistance of the battery changes with time during the charging and discharging process.

　　f. Cycle life

　　Under certain discharge conditions, the number of cycles that the battery can withstand before the battery reaches a certain capacity is called the cycle life. Deep-cycle lead-acid batteries are about 500 to 600 times, and start-up lead-acid batteries are about 300 to 500 times.

　　Lithium-ion battery (LIB) has become the main energy storage solution in modern social life. Among them, lithium iron phosphate batteries are a perfect replacement for lead-acid batteries, and they are the first choice for grid-connected peak shaving, off-grid energy storage, photovoltaic energy storage, UPS, data center and other industries.

　　Compared with lead-acid batteries, lithium batteries have the advantages of long life, small footprint, low load-bearing requirements, simple maintenance, environmental protection, reliability and stability.