Domestic manufacturers are increasing their investment in battery management chips. Who can be the first to overcome the difficulties of automotive-grade BMS chips?

As we all know, lithium batteries have the advantages of being green and environmentally friendly, having a long cycle life, high energy density, and high operating voltage. Since the early 1990s, lithium batteries have officially entered the consumer electronics market such as mobile phones, tablets, and laptops for commercial applications. They have been widely praised by the market and have gradually become the preferred battery for consumer electronics products, power tools, smart home products, smart travel products, new energy vehicles and other products.

To ensure the safety and stability of batteries, battery management chips have gradually become an indispensable key component in the fields of consumer electronics, industrial control, and new energy vehicles.

It is worth noting that in the fields of consumer electronics and industrial control, a large number of domestic brand battery management chips have emerged on the market, but in the field of power batteries used in new energy vehicles, BMS (Battery Management System) chips still rely on imported chips, and there are very few domestic chips.

TI battery management chips are in serious shortage, and local manufacturers are flourishing

It is understood that the batteries used in consumer electronic products such as mobile phones, tablets, and wearable devices are usually single-string battery packs with only 1 to 2 cells. Batteries used in products such as laptops, power tools, vacuum cleaners, electric bicycles, and smart homes are usually multi-string battery packs, consisting of multiple cells connected in series and parallel, but they are less than those in the fields of power batteries and energy storage batteries.

For a long time, the above-mentioned fields have been the main application markets for battery management chips. However, industry insiders pointed out that the technical threshold for entering the field of battery management chips is very high. Since it involves product safety, it requires long-term and in-depth cultivation. Initially, this field was occupied by strong manufacturers such as TI and MAXIM. Subsequently, OMicro, Silergy, and SinoWise Electronics gradually entered this field and occupied a place.

It is worth noting that TI, as a mainstream supplier in the battery management chip market, has fallen into a serious shortage and price increase situation for its products.

According to industry insiders, TI's battery management chip is the BQ series chip. The market gap has been very large since 2020, and the delivery date for product orders has been extended to 2023.

Under this circumstance, many battery management chip manufacturers have emerged in the field of small or medium-sized battery power management systems, including Silergy, Shengbang Electronics, Zhongying Electronics, Lixun Microelectronics, Xidi Microelectronics, Jewatt, Saiwei Micro, and Huatai Semiconductor.

Jiwei.com learned from the industry that although the current overall battery management chip market is still dominated by imported chips such as TI, ADI (acquired MAXIM), and OUMIT Technology, domestic chip manufacturers are gradually completing domestic substitution in the mainstream mobile phone market and occupying a dominant position in emerging consumer electronics markets such as TWS headphones.

In the laptop computer, electric bicycle, power tool, sweeping robot and small energy storage markets, domestic chip manufacturers are also stepping up verification and testing and are in the growth stage of domestic substitution.

According to a domestic chip manufacturer, at this stage, domestic terminal manufacturers and lithium battery manufacturers have a strong demand for domestic chip substitution. We will launch exclusive customized chips for leading customers. We are currently in the stage of mass production of products and the market demand is very large.

Automotive-grade BMS chips rely on imports, and ASIL-D certification may become a stumbling block

With the rapid increase in the production of new energy vehicles, the demand for power batteries, as the core components of new energy vehicles, has continued to grow and has become the dominant force in the growth of the lithium battery industry.

Generally speaking, the power battery of an electric vehicle needs to be composed of thousands of battery cells. Due to problems such as errors in the production process of the battery cells and differences in the use environment, even two battery cells produced in the same batch cannot have completely consistent performance. During use, the inconsistency will gradually expand, and dangers such as overcharging, over-discharging and local overheating may occur, seriously affecting the service life and safety of the battery pack. This requires BMS to manage the battery.

However, as one of the core raw materials of power batteries, BMS chips still need to rely on imports.

Zeng Yuqun, chairman of CATL, said at a recent research activity that CATL does not directly involve American technology, materials or equipment in the battery production process. The only thing it relies on the United States now is the chip in the BMS, but the process technology is not high, 28nm is enough, and domestic technology is already available.

Industry insiders pointed out that BMS chips mainly include AFE, MCU, ADC, digital isolators, etc. Suppliers that can provide complete solutions for automotive-grade BMS chips mainly include ADI (AFE products mainly come from the product lines acquired from MAXIM and Linear), TI, Infineon, NXP, Renesas (AFE products mainly come from the product lines acquired from Intersil), ST and ON Semiconductor.

Among them, the BMS AFE chip (analog front-end chip) is responsible for collecting the battery voltage and converting it into a digital value through an analog-to-digital converter (ADC), and sending it to the MCU to calculate the charge state.

In terms of automotive-grade MCUs, according to incomplete statistics from Jiwei.com, in recent years, domestic manufacturers including Jefa Technology, Allwinner Technology, GigaDevice, Xinwang Micro, Saiteng Micro, Xiaohua Semiconductor, Chipways, Xinhai Technology, Yuntu Semiconductor, and Xinwang Microelectronics have all had chip products that have passed the automotive-grade AEC-Q100 certification.

As for BMS AFE chips, this chip has the highest technical difficulty and the highest added value, and there are relatively few domestic manufacturers involved in this product. According to public information, BYD Semiconductor has launched an automotive-grade AFE chip that meets the AEC-Q100 standard; Chipways' automotive-grade BMS AFE chip (meets ASIL-C level) has also been successfully mass-produced.

In addition, Silergy already has BMS AFE chip products, but they are mainly used in the industrial field. Xinhai Technology, Saiwei Micro, and Huatai Semiconductor have also stated that they will develop multi-cell BMS chips.

It is worth noting that as one of the core control systems of new energy vehicles, BMS needs to support the most stringent functional safety scenarios in the automotive industry. "Currently, automotive OEMs have proposed that the functional safety of BMS needs to reach ASIL-D level, which requires the design of redundant functions for BMS chips to ensure the coverage of failure modes, further increasing the difficulty of chip design."

Industry insiders pointed out that the verification cycle of automotive-grade BMS AFE chip products will reach 1.5 to 2 years, and it will take at least 4 years from product definition to production. For demanding automotive application environments, in addition to the reliability needing to meet the AEC Q100 Grade1 quality standard, the ISO 26262 automotive safety integrity level ASIL-D certification may become a stumbling block for domestic chip manufacturers to develop BMS chips.