The price of lithium battery is mainly composed by 3 main accessories: Battery Cell, Protective Board and the Battery Case. At the same time, due to appliances power consumption and electric current, cell connectors material selection (conventional nickel piece, formed nickel piece, copper-nickel composite piece, straddle piece, etc.) will affect the cost. Different connectors (such as aviation plug, from more than 2 dollars to thousands of dollars) may have a greater impact on the cost. Also, different pack process will affect the cost.
1. Cell Selection
Firstly, the selection of cell type with different material systems will affect the total lithium battery price. According to the different cathode materials, lithium battery will have lithium manganate (3.6 v) , Lithium Cobalt (3.7 v / 3.8 v) , lithium nickel cobalt manganate (commonly known as Ternary, 3.6 v) , Lithium Iron Phosphate (3.2 v) , Lithium Titanate (2.3 v / 2.4 v) and other materials system of cells. Regarding the different material system, their voltage platform, safety situation, cycle life, energy density ratio, working temperature are different.
Secondly, the prices of different brand battery cells will be a great difference. The total price gradient can be divided into: Special Cell (including ultra-low temperature, ultra-high temperature, ultra-high multiplying power, abnormal shape) , Japanese Cell (Panasonic, Sanyo, Sony) , Korean Cell (Samsung, LG) , Domestic cell (domestic cell can be divided into first Level( CATL, BYD, ATL) , second level, even five, six levels) . The cells with the same material system but different brands, prices difference can be very large, and through the market competition, the cell quality (safety, consistency, stability) is basically proportional to the price.
2. PCM Demands and Design
PCM designs can be divided into Basic Protection, communication, and BMS
Basic protection: The basic protection includes over-charge, over-discharge, over-current and short-circuits protection, which can be increased heating protection according to production demands.
Communication: Communication Protocol can be divided into I2C, RS485, RS232, CANbus, HDQ, SMBUS, etc. There is simply power display by power meter LED instructions.
BMS: BMS is the first acronym of the battery management system, called Battery Management System, mainly for intelligent management and maintenance of each battery unit, to prevent the battery from over-charge and over-discharge, extend battery life and monitor battery status. Its main functions include battery physical parameters real-time monitor; battery state estimation; on-line diagnosis and early warning; charge, discharge; pre-charge control; balance management and thermal management. This system is mostly used in the electric vehicle battery.
3. Case Demand and Design
Lithium battery case design can be divided into PVC heat seal, plastic, metal.
PVC Heat Seal: Battery Pack external shell packaging form, mainly depends on the customer’s product specific demands. For the PVC heat seal packaging form, generally applicable to the number of cells series or parallel not much, and the overall weight is lower (≤2 kg). However, for batteries with an overall weight of more than 1 kg, it is necessary to add a fixed bracket between the cells and a glass fibreboard around the battery before applying PVC heat seal.
Plastic: Plastic Shell may need to make the mold, mold cost is not a small amount. When pre-development, product unshaped, you can use the hand made shell ( the hand made shell strength is not as strong as mold shell), Shell material and technology (especially with other requirements), will also affect the cost.
Metal: Metal Shell is the same as plastic shell, it is recommended to use sheet metal to make the sample if the product is not shaped or the quantity is not much. In this way, the delivery period is short. For the large batch, it is also recommended to open mold. Also, metal shell waterproof level requirements and special material requirements will greatly affect the cost.
The cost of lithium battery is mainly composed of the battery cell, PCM, structural components, plus enterprise PACK costs, aging costs, management costs and so on. At the same time, due to the technical difficulties, procurement volume, defective rate, lithium battery prices will vary greatly!
SmartPropel Original Work Writer：Nancy