Lithium Ion Single Cell Voltage

Lithium ion cells are susceptible to stress by voltage ranges outside of safe ones between 2 5 and 3 65 4 1 4 2 or 4 35v depending on the components of the cell.

Lithium ion single cell voltage.

Some cell manufacturers mark their li ion as 3 70v cell or higher. The nominal voltage is measured at the mid point between full charged and fully discharged based on a 0 2c discharge where c is the rated capacity of the cell in mah. Please see the table below to see advantage and disadvantage of each type cell. Exceeding this voltage range results in premature aging and in safety risks due to the reactive components in the cells.

What this means is that the maximum voltage of the cell is 4 2v and that the nominal average voltage is 3 7v as the battery is used the voltage will drop lower and lower until the minimum which. The 3v to 4 1v provided by a lithium ion cell is also a good match for modern low voltage circuits often simplifying the power supply. The nominal cell voltage of 3 60v can directly power mobile phones tablets and digital cameras offering simplifications and cost reductions over multi cell designs. Among of them licoo 2 series li ion cell has the highest energy density and is most popular cell using in the market.

Lithium iron phosphate technology has the flattest discharge curve which makes it very difficult to estimate soc on a simple voltage measurement. Types of lithium ion batteries. However lithium ion batteries have a much flatter discharge curve which means that over a wide operating range the voltage at the battery terminals changes very slightly. The 3 70v cell rating also creates unfamiliar references of 11 1v and 14 8v when connecting.

For example almost all lithium polymer batteries are 3 7v or 4 2v batteries. For li ion cells they should not be discharged below 2 5v and it s even better if the minimum cell voltage is limited to 3 volts. This offers a marketing advantage because the higher voltage boosts the watt hours on paper voltage multiplied by current equals watts. The loss of capacity resulting from the higher cutoff voltage is small because lithium cell voltage drops very quickly when it reaches the discharge limit.

The drawbacks are the need for protection circuits to prevent abuse as well as high price. Depending on the design and chemistry of your lithium cell you may see them sold under different nominal voltages. Lifepo4 and limnnio4 cell still are in developing. There are three types of li ion cells on current market based on chemistry of cathode materials.

The lithium battery output voltage varies during discharging.