When discharging, the voltage of the lithium battery will gradually decrease with the passage of electricity, and there is a considerable slope. This provides us with another method of approximately measuring electricity. The method of obtaining battery voltage is like measuring the height of the water in a water tank to estimate the amount of water remaining. But in fact the voltage of the battery is much more complicated than the level measurement in the water tank.

　　The greater the discharge current, the lower the voltage. In the absence of current, the voltage is the highest. As the cycle progresses, the discharge platform of lithium-ion batteries tends to deteriorate. The emission platform is reduced. Therefore, the capacity represented by the same voltage will change accordingly.

　　For the same lithium-ion battery, under the same remaining capacity, the voltage value changes due to the magnitude of the discharge current. Different manufacturers and different capacity lithium-ion batteries have slightly different discharge platforms.

　　In the process of grouping lithium batteries, due to the subtle differences in the materials of the lithium battery cores and the different levels of the molding process, the functional performance of the lithium battery cores will be inconsistent during use and placement. This is a discrete phenomenon of lithium batteries. The quantitative index describing this discrete phenomenon is dispersion, which is obtained by the functional relationship of several parameters. The main factors that cause the variation of the dispersion value are: resistance, voltage, capacity, temperature, etc.

　　1. The internal resistance of the lithium-ion battery, especially the inconsistency of the polarization internal resistance, causes the voltage of a single battery to change drastically during the charge and discharge process, resulting in drastic changes in the entire battery pack;

　　2. The voltage inconsistency of a single ultra-thin battery will affect the peak regulation capability of the lithium battery pack, which will reduce the emission energy of the entire battery pack;

　　3. Due to the heat dissipation and heat absorption process of the ultra-thin battery, the battery temperature will continue to change. When overheating, it will bring performance degradation and safety hazards.