The battery pack is A battery assembly form consisting of multiple battery cells. The voltage of the battery pack refers to the voltage value of the entire battery pack in the working state. The voltage of the battery pack directly affects the output performance, service life and safety of the battery pack. This article will introduce the voltage concept, calculation method, common types and its application in different fields of battery pack.

1. Voltage concept of battery pack
   the voltage of the battery pack is the sum of all cell voltages. When connected in series, the voltage of the battery pack is equal to the sum of the voltage of each cell; When connected in parallel, it is equal to one of the voltage of each cell. The voltage of the battery pack is usually expressed in volt (V). Different types of battery packs have different rated voltage values, such as the rated voltage of lead-acid battery pack is 12V, and the rated voltage of lithium ion battery pack is 3.7V.

2. Voltage calculation method of battery pack
   in the battery pack connected in series, the total voltage of the battery pack is equal to the sum of the voltage of each battery cell; In the battery pack connected in parallel, the total voltage of the battery pack is equal to the voltage of one of the battery cells. For example, a battery pack consisting of three lithium-ion battery monomer sections has a total voltage of 3.7V * 3=11.1V when connected in series and 3.7V when connected in parallel.

3. Common battery pack types and their voltage
   there are various types of battery packs. The common types of battery packs and their rated voltage are as follows:

• lead-acid battery pack: the rated voltage is 12V, which is commonly used in automobile starting, ups power supply and other fields.
• Lithium ion battery pack: the rated voltage is 3.7V, which is widely used in mobile devices, electric tools and other fields.
• Nickel-hydrogen battery pack: the rated voltage is 1.2V, which is common in wireless telephones, electronic toys and other fields.

4. Importance of battery voltage
   the voltage of the battery pack is the basis of the work of the battery pack, which directly affects the output performance and service life of the battery pack. Reasonable selection of voltage value of battery pack can meet the demand of equipment for power supply and improve the operation efficiency and stability of equipment. In addition, the voltage value of the battery pack is also closely related to the safety during charging and discharging. Too high or too low voltage will affect the safety and life of the battery pack..

5. Application of battery voltage in different fields
   the voltage of battery pack has important applications in various fields, including but not limited:

• electric vehicle: the battery pack voltage of electric vehicle directly affects the mileage and performance of the vehicle.
• The battery pack voltage in solar energy storage system: solar energy storage system determines the energy storage capacity and output power of the system.
• Portable devices: the battery pack voltage is adapted to different portable devices, providing stable power support.

The voltage of the battery pack is the basis of the work of the battery pack, which directly affects the output performance and service life of the battery pack. The key to ensure the stable operation of the equipment is to correctly select the voltage value of the battery pack and reasonably manage the use of the battery pack.