The charge-discharge curve is a key parameter of battery performance. So, what does the charge-discharge curve mean? What are the charge-discharge curves of lithium batteries and lead-acid batteries?

　　When the battery is discharged, its working voltage always changes with the continuation of time. Use the working voltage of the battery as the ordinate, discharge time, or capacity, or state of charge (SOC), or depth of charge and discharge (DOD) The curve drawn by drawing the abscissa is called the charge-discharge curve.

　　According to the charge and discharge curve, it can be judged whether the battery performance is stable, and the maximum current allowed by the battery in stable operation.

　　For the same fully charged lead-acid battery, at the same temperature, using different rates of discharge current, the discharge output characteristics are very different, resulting in unstable power.

　　Lead-acid battery charge and discharge curve

　　For the same lithium battery, at the same temperature, using different rates of discharge current, its discharge output characteristics are very stable, and the charge and discharge efficiency is much higher than that of lead-acid batteries.

　　Lithium battery charge and discharge curve

　　It can be seen from the charge and discharge curves of the two that the efficiency of lead-acid batteries is very different when discharged at different rates, while there is no difference between lithium batteries.

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