Cost analysis of forklift lithium battery

Since last year, as lithium electricity boom in China's forklift industry gradually arisen, China forklift keep up with the latest development trend of the industry, speed up the pace of lithium electricity market visit, from north to south, from west to east, successively visited dozens of new energy related enterprises, these enterprises have different size, we visited the high standards of fully automated assembly line production mode, also saw a very crude way of manual assembly. With the in-depth investigation, we find that there are various good and bad phenomena in the new energy market, among which the most prominent is the confusion of quality and price. Therefore, in view of this phenomenon, I get some of the information in the market according to oneself and professionals to provide information on current lithium battery forklift cost to do a simple analysis, because my level is limited, know the information is not very comprehensive, inevitably there will be some mistakes in this paper, welcome the industry comment, appreciate.

I. composition of lithium battery products

Generally speaking, a complete set of power lithium battery system is usually composed of cell, battery management system (BMS), Pack system (including functional components), wiring harness, structural parts and other related components. The power lithium battery system mode can be divided into three different hierarchical modes, namely cell mode, battery management system mode and Pack system integration mode.

Ii. Cost of lithium battery cells

Battery cell: refers to a single electrochemical independent unit containing positive and negative electrodes. Generally, the battery cell is not used directly, and requires a battery management system or simple protection board. The quality of the battery cell directly determines the quality of the battery pack. According to incomplete statistics, there are hundreds of battery factories in China, with a wide range of quality, from simple lithium batteries for flashlights to batteries for the automobile industry. Generally speaking, the latest equipment and the latest technology produced the best quality, the highest energy density, the most stable quality, the highest security.

The battery cell occupies 80% of the cost of the lithium battery pack, which is the most expensive part of the lithium battery pack and directly determines the safety life and price of the lithium battery pack. The current cell price in the market, if the scale of the reference to the auto industry matching consistent qualified cell monomer price, take the lithium iron phosphate battery as an example, the price is generally in 1.2~1.3 yuan /WH.

A. For cell manufacturers, it is impossible to achieve 100% consistency for A single cell in mass production, and there will be voltage difference and resistance difference for each single cell. After the test and screening, the most consistent products are used for the matching of new energy vehicles. The quality assurance conditions of the manufacturer can be 5 years /4000 times / 10,000 hours / 200,000 kilometers. This part of the cell is called product A. The selected products that are inconsistent with the standard are called B products in the industry. This part of products are generally sold to the industry with low quality requirements, such as backup power supply that requires 1000 times of charging cycle, energy storage power station or low-speed electric two-wheelers and tricycles with a life of about 2 years. The market price of B cell is generally 0.6~0.8 yuan /WH. That's about half the price of a premium product for the auto industry.

Iii. Battery management system BMS

All regular lithium-ion battery pack, be sure to install the battery management system (BMS), lithium battery management system generally adopts the integrated design, integrated the battery voltage, temperature detection, protection, SOC estimation (power estimation), balanced management, communication and remote monitoring, and other functions, the purpose is to protect lithium battery in the process of using safety and prolong the service life of the battery pack. There are many domestic manufacturers of battery management system, and there are also great differences in quality. Take the battery management system of a 48-v forklift battery pack as an example, the price is generally between 1400 yuan and 2500 yuan. In addition, a small number of less security-conscious suppliers of lithium-ion batteries have adopted protection panels (which function like the voltage and time potentiometers of ordinary lead-acid chargers) for about $200 to save costs. The cost of a battery management system makes up about 10% of a finished lithium-ion battery pack. The price difference between high quality BMS and poor products is about 2000 yuan.

Iv. Pack system includes functional components, wiring harness, structural parts and other related components

Pack system integration is equivalent to forklift machine assembly, and the level of technology determines the quality and failure rate. A lot of lithium battery Pack finished products in use, usually have the phenomenon of internal welding fracture, even some large Pack factory products will appear this problem. Therefore, the quality of cell integration and contacts such as connectors are the focus of frequent quality problems.

Differences in functional components can be illustrated by examples. Take relays as an example, the manufacturers that pay attention to safety and quality all use Tyco relays. The single cost of the two relays is about 650 yuan per relay, while some cheap relays only need 200 yuan per relay. In addition, there are hall current sensor and other components of the quality price is also a big gap.

In terms of Pack production process, large-scale manufacturers adopt large-scale laser welding process to ensure the safety and stability of products. However, some small Pack assembly plants adopt simple copper strip soft connection to reduce costs, which cannot guarantee the safety and performance stability of products for a long time. The cost difference for this part is about 2,000 yuan.

Total cost of lithium battery system integration

From what has been discussed above, we with 48 v / 400 ah lithium iron phosphate (19.2 KWH / 19200 WH), for example, A level batteries production procurement costs about 26000 yuan/group (close to import prices of lead-acid battery), plus the normal battery management system (BMS), then the Pack on the function of the system contains components, wiring harness, structure and related components, counterweight block, and the company's management cost, r&d cost, reasonable profit and other factors, the market price range is generally in 4 ~ 50000 yuan/set, scaling down is about 2.2 ~ 2.5 yuan/WH, This is a relatively reasonable price range. For B grade or lower quality battery products, the procurement cost of the battery is about 14,000 yuan/set (cheaper than the price of domestic lead acid), and the market price of the battery set is about 25,000 to 30,000 yuan/set, which translates to 1.2 to 1.5 yuan /WH. If it is 80V/500AH, for example, the cost difference of a single battery pack is as high as more than 20,000 yuan. The wide price gap provides a lucrative niche for small battery assembly plants (packs) that do not pay attention to safety, quality or longevity.

During our visit, we often hear different opinions. Some people take it for granted that A is used for cars and B is used for forklifts. In fact, if you really understand the working conditions of forklift, you will find that the quality and safety requirements of lithium battery for the working conditions of forklift will not be lower than the automotive industry. However, since the lithium battery has not been in the forklift industry for a long time, the forklift industry does not have its own lithium battery standard yet, and it is difficult for customers to be able to distinguish the advantages and disadvantages of products. Even if the battery is opened for inspection, the quality or even the old and new ones cannot be distinguished without detection equipment.

Six, summarized

The application of new energy in the forklift industry has just started to develop on a large scale and is in the ascendant. In this excellent situation, how can our colleagues keep a cool head in the competitive market, study lithium battery products down-to-earth, learn more about lithium battery industry, correctly choose and use lithium battery with high quality and high safety, and jointly care for and cultivate our forklift new energy market? At the same time, I also hope that the majority of peers can be more involved in the discussion and exchange of new energy, to bring more positive energy for the development of new energy forklift, so that lithium battery can better serve industrial vehicles.