What are the voltage and charging voltage of a lithium battery

1. Ordinary lithium-ion batteries (Li ion, such as mobile phone and laptop batteries)

Nominal voltage : 3.6V or 3.7V

-Charging voltage (cut-off voltage): 4.2V ± 0.05V

-Discharge cut-off voltage * *: 2.5V~3.0V (below this voltage may damage the battery)

-Typical application * *: Consumer electronics products (mobile phones, tablets, laptops, etc.).

2. Lithium iron phosphate battery (LiFePO ₄)

-Nominal voltage : 3.2V or 3.3V

-Charging voltage (cut-off voltage): 3.6V~3.65V

-Discharge cut-off voltage : 2.0V~2.5V

-Features : High safety, long cycle life, commonly used in electric vehicles and energy storage systems.

3. Lithium polymer battery (Li Po)

– Nominal voltage : 3.7V (the same as ordinary lithium-ion batteries)

-Charging voltage: 4.2V (single section)

-Discharge cut-off voltage : 3.0V

-Features : Flexible in shape, commonly used in drones, model aircraft, and mobile devices.

Charging precautions

1.  Charging method : Lithium batteries require constant current constant voltage (CC-CV) charging method. First, charge with constant current until the cut-off voltage is reached, and then charge with constant voltage until the current approaches zero.

2. Overcharge risk: Exceeding the cut-off voltage (such as lithium-ion batteries exceeding 4.25V) may cause the battery to swell, catch fire, or explode.

3. Protection circuit : A protection board (BMS) is required to prevent issues such as overcharging, over discharging, and short circuits.

4. Multi cell battery pack : When used in series, balanced charging is required (such as a 12V lithium battery pack consisting of 3 cells connected in series, with a total charging voltage of 12.6V).

Summary

-Voltage range of a single lithium battery:

-Lithium ion/lithium polymer: 3.0V~4.2V

-Lithium iron phosphate: 2.5V~3.65V

-The charging voltage must strictly match the battery type, as incorrect voltage may cause safety hazards!

For specific applications such as electric vehicles, power banks, etc., please refer to the battery specification sheet or equipment manual.