Lithium battery pack increases voltage

Constant Voltage Charging Stage: When the lithium battery voltage reaches 4.2V, charging enters a constant voltage state, maintaining this voltage while the current gradually decreases over time until charging is complete. When discharging, the trend of voltage change in lithium-ion batteries is the opposite of charging.

These changes are closely related to the battery's internal chemical reactions and physical characteristics. In the initial phase of charging, the lithium battery voltage is usually low, and as the internal chemical reactions of the battery gradually reach equilibrium, the voltage rises.

During charging, lithium-ion batteries exhibit distinct voltage characteristics that reflect their electrochemical processes. The charging cycle typically follows a constant current-constant voltage (CC-CV) protocol. Initially, the battery voltage rises steadily as current flows into the cell.

For most lithium-ion batteries, the charging voltage peaks at 4.2V, while the cutoff voltage during discharge is typically 3.0V. Exceeding these limits can lead to overheating, capacity loss, or even thermal runaway. To avoid overcharging, use chargers specifically designed for your battery type.

The lithium battery voltage experiences significant fluctuations during charge and discharge, influenced by various factors, including the differences in nominal voltage among different materials, voltage fluctuations during charge and discharge processes, and the impact of voltage changes on battery performance.

Using this method, the presented study statistically evaluates how experimentally determined parameters of commercial 18650 nickel-rich/SiC lithium-ion cells influence the voltage drift within a 168s20p battery pack throughout its lifetime.