Available voltage of lithium battery pack

The most important key parameter you should know in lithium-ion batteries is the nominal voltage. The standard operating voltage of the lithium-ion battery system is called the nominal voltage. For lithium-ion batteries, the nominal voltage is approximately 3.7-volt per cell which is the average voltage during the discharge cycle.

Common lithium-ion cells typically have a nominal voltage of about 3.6 to 3.7 volts. This range is standard for most consumer applications, including smartphones and laptops. The actual voltage can vary slightly based on the specific chemistry and design of the cell. Most lithium-ion batteries consist of multiple cells connected in series.

Single lithium polymer (Li-Po) cells typically have a nominal voltage of 3.7 volts. When the voltage of this type of cell is charged to 4.2 volts, it is considered fully charged. During the battery discharge process, when the voltage drops to 3.27 volts, the battery is considered fully discharged.

Lithium-ion batteries function within a certain range at which their voltage operates optimally and safely. The highest range where the fully charged voltage of a lithium-ion battery is approximately 4.2V per cell. The lowest range which is the minimum safe voltage for lithium-ion batteries is approximately 3.0V per cell.

Usage Range: Ideally, for optimal performance, lithium batteries should operate within a voltage range of 3.2 to 4.1 volts. Other specialized lithium batteries, such as lithium iron phosphate (LiFePO4), have different voltage parameters, typically around 3.2 volts nominal.

The SoC voltage chart for lithium batteries shows the voltage values with respect to SoC percentage. A Li-ion cell when fully charged at 100%SoC can have nearly 4.2V. As it starts to discharge itself, the voltage decreases, and the voltage remains to be 3.7V when the battery is at half charge, ie, 50%SoC.