Ngenxa ye-voltage elinganiselwe namandla ebhethri elilodwa, inhlanganisela yochungechunge-parallel iyadingeka ukuze uthole i-voltage ephakeme kanye nomthamo, which can meet the actual power supply requirements of different devices that are powered by lithium battery packs.

• Lithium batteries in series: the voltage is added, the capacity stays the same, and the internal resistance increases.
• Lithium batteries in parallel: the voltage stays the same, the capacity is added, the internal resistance is reduced, and the power supply lasting time is extended.
• Lithium batteries in series and parallel: There are both parallel and series combinations among lithium batteries, which increases both the voltage and the capacity of the whole battery pack.
• Battery pack Voltage of series connection: the voltage is added when the battery cells are connected in series. Ngokwesibonelo, 3.7V single cells can be assembled into a battery pack with a voltage of 3.7*(N)V as required (N: the number of single cells), such as 7.4V, 12V, 24V, 36V, 48V, 60V, 72V, njll.

• Battery pack capacity of parallel connection: the capacity is added when the battery cells are connected in parallel. Ngokwesibonelo, a 2000mAh single battery can be assembled into a battery pack with a capacity of 2*(N)Ah as required (N: the number of single cells), such as 4000mAh, 6000mAh, 8000mAh, 5Ah, 10Ah, 20Ah, 30Ah, 50Ah, 100Ah, njll.

Lithium battery pack refers to the processing, assembly, and packaging of lithium battery packs. The process of assembling lithium batteries into a group is called PACK.

A PACK can be a single battery or a series and parallel lithium battery pack. A lithium battery pack is usually composed of a plastic shell, protective plate, battery core, output electrode, contact piece for connection, and other insulating tapes, double-sided tapes, njll. Below are some main components:

1. Lithium battery cell: the core part of the finished battery
2. Protection board（BMS）: also called BMS (battery management system), can protect the battery pack to avoid overcharge, over-discharge, overcurrent, short circuit, and NTC temperature control intelligent protection.
3. Plastic shell: the supporting skeleton of the entire battery; the positioning and fixing of the protection plate; carrying and limiting all other non-shell parts.
4. Terminal lead: Various terminal wire charging and discharging interfaces can be provided for various electronic products, energy storage products, and backup power supplies.
5. Nickel Strip/bracket: connecting and fixing components of the cell

Due to safety reasons, lithium batteries must be connected to an external protection board (I-BMS) for monitoring each battery.

It is generally not recommended to use batteries in parallel. If they are connected in parallel, the consistency of battery parameters (umthamo, ukumelana kwangaphakathi, njll.) must be ensured. The batteries used in series must also have the same parameters, otherwise, the performance of the battery pack will be much worse than that of a single cell.

Lithium battery pairing standard Voltage difference≤10mV, internal resistance difference≤5mΩ, capacity difference≤20mA

The purpose of lithium battery pairing is to ensure that the capacity, voltage, ukumelana kwangaphakathi, and effect of each battery in the battery pack are consistent. Inconsistency will lead to various battery parameters during the use of the lithium battery pack. If the battery voltage is imbalanced, the battery pack will be overcharged, or over-discharged, and the capacity will not be exerted, causing the danger of explosion and fire.

We all know that when the batteries are under series connection, the voltage of lithium batteries increases, and when they are under parallel connection, the capacity of lithium batteries increases, so how to calculate the number of series and parallels of a lithium battery pack? and how many cells are needed to be composed?

Before the calculation, we need to know the battery cell specification that is used for the assembly of this lithium battery pack. Because different cells have different voltage capacities, the number of series and parallel required to assemble a lithium battery pack of a specific specification is different.

Common types of lithium batteries include 3.7V for lithium cobalt oxide, 3.6V for ternary, 3.2V for lithium iron phosphate, and 2.4V for lithium titanate.

The capacity varies depending on the size, material, and manufacturer of the battery cell. Take a 48V 20Ah lithium battery pack as an example:

Assuming that the single cell specification used is 18650 3.7V 2000mAh

Number of parallel cells: 20Ah/2Ah= 10 (10 cells in parallel)

Number of series cells: 48V/3.7V=13 （13 cells in series）

The whole set of batteries is 13 × 10 = 130 cells

So to make a 48V 20AH lithium battery pack, we need 130pcs of 18650 3.7V 2000mAh battery cells to make in 13S10P.

• Do not use batteries of different brands together.
• Do not use batteries of different voltages together.
• Do not mix different capacities or old and new lithium batteries.
• Batteries of different chemical materials cannot be mixed, such as nickel-metal hydride and lithium batteries.
• When the battery power is low, replace all batteries.
• Use the lithium battery protection board (I-BMS) with the corresponding parameters.
• Choose batteries with the same performance. Generally, lithium batteries need to be paired in series and parallel. Matching standard: voltage difference≤10mV, internal resistance difference≤5mΩ, capacity difference≤20mA