The lithium-ion battery pack is a complete battery pack formed by assembling several electric cells in series and parallel. This process is also the PACK technology of lithium battery. That is, when the rechargeable batteries are assembled in series and parallel, the lithium ion battery pack with random voltage capacity can be made. So how many volts and milliampere hours do we usually talk about? I believe there are still many friends who do not know how to distinguish, what each number represents, and how to calculate to make a lithium battery pack that meets the specifications. Now let's use a set of 48V20AH lithium battery pack to explain to you.
The voltage is increased in series and the capacity is increased in parallel. The standard voltage of the ternary lithium ion battery is 3.7v, which is full of 4.2v. Three strings are 12v, and 48v must be four three strings. However, the lead acid battery of the new energy electric vehicle is the most powerful when it is fully charged at 58v. Therefore, the lithium battery must also be up and down to 58v. This must be 14 strings to 58.8v, 14 times 4.2, and the lithium iron battery is up and down to 3.4v when it is fully charged. Four strings must be 12v, 48v must be 16 strings, and so on. 60v must be 20 strings, With the same model and capacity in parallel, two 10ah lithium battery cells in parallel are 20ah.
48V refers to the voltage. Generally speaking, the ternary lithium ion battery refers to 48. Except for 3.7, 13 series and 14 series are basically 48V. The 13 series are charged with a 54.6V rechargeable battery charger, and the 14 series are charged with a 58.8V rechargeable battery charger. So 20 ampere hours refers to the battery capacity. Each 18650 lithium battery cell has a capacity of 2000 mA. That means 2 ampere hours for each cell. Ten lithium battery cells together are 20 ampere hours.
Lithium ion batteries are connected in series: the lithium ion batteries are connected head to tail. That is, the positive pole of the first battery is connected to the negative pole of the second battery, the positive pole of the second battery is connected to the negative pole of the third battery, and so on. The series voltage is equal to the sum of battery voltages, and the current is equal to the current flowing through each battery. The damage of one section of the lithium-ion battery pack will cause the entire battery pack to be unusable or the voltage to be reduced.
Lithium ion batteries are connected in parallel: the lithium ion batteries are connected head to head and tail to tail. That is, the positive poles of all batteries are connected and the negative poles of all batteries are connected. The parallel voltage is equal to the voltage of a single battery, and the current is equal to the sum of the battery currents. Parallel connection can increase the total current.
Lithium ion battery packs shall be combined in series and parallel to achieve the required voltage and capacity. Batteries are generally connected by nickel sheets. This special equipment is required to weld the nickel sheets with the cell, which is relatively secure and safe. Then connect the corresponding protection before output.