BMS chips welcome more players

As the core of the battery management system, the BMS chip undertakes key tasks such as monitoring battery status, ensuring battery safety, and extending battery life. It is like a "guard" that silently protects the health of the battery, always paying attention to the battery's voltage, current, temperature and other parameters to ensure that the battery operates within a safe and reliable range.

In recent years, the BMS chip market has been booming. More and more companies have seen the huge potential in this field and have joined the battle. It is understood that, including the players who are about to enter the market, more than 50 domestic manufacturers have entered this track.

What is a BMS chip?

BMS battery management system is the core component of the battery pack. BMS system can realize intelligent management and maintenance of each battery unit, prevent overcharging and over-discharging of the battery, extend the battery life and monitor the battery status. BMS system is a key component in the battery, which is mainly composed of hardware circuit, underlying software and application layer software. The main chips used in BMS are AFE, fuel gauge, MCU, ADC, isolation chip, etc.

Typical BMS architecture block diagram (Source: TI)

Analog front-end chip (AFE)

The AFE chip is the core chip of the BMS. Among them, the AFE analog front-end chip (specifically the battery sampling chip in the BMS) is used to collect information such as cell voltage and temperature, and also supports the battery balancing function. Generally speaking, the chip will integrate a passive balancing function. The fuel gauge is used to determine the remaining power in the rechargeable battery and the battery's continued power supply time under specific working conditions. In some cases, it will be integrated into the AFE.

AFE original manufacturers include Analog Devices, Texas Instruments, STMicroelectronics, Panasonic, NXP, Renesas, Microchip, MPS, BYD Semiconductor, Qipuwei, Datang NXP, Silergy, Xinhai, Shengbang, Saiwei Microelectronics, Zhongying, Pengshen Technology, Jewatt, Lixun Micro, Xidiwei, Huatai Semiconductor, and Xinxiang Technology.

Computing Unit (MCU)

MCU (Microcontroller Unit) is the core computing and control unit of BMS, responsible for data processing, battery status monitoring, control algorithm execution, fault diagnosis, communication management and other functions.

MCU original manufacturers include Texas Instruments, STMicroelectronics, NXP, Infineon, Renesas, Zhongying, GigaDevice, Xinhai, National Technology, Saiteng Micro, Jiefa, Xinwang, Xiaohua Semiconductor, Yuntu, Qipuwei, BYD Semiconductor, Xinchi, Hangshun, Xianji, Qixin Micro, Shanghai Hangxin, Xinqing, Zhongke Haixin, AMEC, Huimang Micro, Jiuhai, Xihua, etc.

ADC (Analog-to-Digital Converter)

The main function of the ADC chip is to quantify the analog signal in the BMS and generate a signal amplitude that can be represented digitally.

ADC original manufacturers include Texas Instruments, Analog Devices, Microchip, NXP, Analog Devices, Shengbang, SiRuiPu, Shanhai Semiconductor, Xinhai, Xunxinwei, Yunxin, Huatai Semiconductor, Xindong Shenzhou, Belling, Lingsi Micro, and Aerospace Minxin.

BMS continues to attract new players

In the battery management chip industry, European and American manufacturers such as TI and ADI occupy the vast majority of the market share.

TI has made remarkable achievements in the field of BMS. Its battery sampling chips have many material numbers, and are particularly outstanding in iterative innovation. In 2019, TI launched the 3-6 battery sampling chip BQ79606. The sampling accuracy of this chip is less than 1.1mV, and it can complete the full-precision measurement of the stack in just 1ms. It can handle up to 96 batteries and supports isolated differential daisy chain communication. Since then, TI has been speeding on the road of innovation. In 2020 and 2021, TI quickly iterated and upgraded the battery sampling chip, increasing the number of measurable battery strings to 12, 14, and 16, respectively.

ADI first launched a high-performance battery sampling chip LTC6804 as early as 2013. In the past few decades, it has invested in the research and development of chips and system software to solve a series of problems in the BMS system. ADI's BMS products have three outstanding features. The first is very high accuracy; the second is high long-term reliability. The detection accuracy is still very high after 15 years; the third is very reliable. ADI's products have been tested in many actual mass-produced models and have been iterated to the seventh generation.

Domestic companies that have already mass-produced battery management chips and achieved revenue include Zhongying Electronics, Shengbang Electronics, Lixun Microelectronics, Saixin Microelectronics, Shanghai Belling, Xidi Microelectronics, AMEC, Xinhai Technology, Saixin Electronics, Microsource Semiconductor, Zhirong Technology, Yutai Semiconductor, Toer Micro, Jewatt, BYD Semiconductor, as well as Maoruixin and Chuangxin Microelectronics.

China's BMS industry started relatively late. In terms of the application market, China has achieved certain breakthroughs in the field of BMS for low-end and mid-range consumer electronics, and its performance is close to international standards. There are many large manufacturers mass-producing lithium battery management applications for mobile phones and TWS headphones, and the application of laptops has also been recognized and adopted.

Zhongying Electronics is the first company in China to develop BMS battery management chips. In 2012, it successfully launched battery management chips for electric bicycles, electrical tools, and laptops. In the BMS track, Zhongying Electronics focuses on the research and development of battery metering chips, battery protection chips, and battery sampling chips. The current products are mainly SH36730 series, covering 3-5 strings, 6-8 strings, 10 strings, 14 strings, and 16 strings of batteries.

For example, SH367309 is a digital front-end chip for 5-16 lithium battery BMS, suitable for lithium battery packs with a total voltage not exceeding 70V. What is more special is that this AFE chip of SinoWise Electronics also integrates a wealth of protection functions, including charging protection, over-discharge protection, temperature protection, charge and discharge over-current protection, short circuit protection, secondary over-charge protection, etc.

Saiwei Microelectronics is one of the domestic companies with a relatively complete product line of battery management chips. It started mass production of its first power meter chip in 2013. Its metering chips have been used in many electronic products and are widely praised for their extremely low power consumption, ultra-small packaging and accurate power metering.

For example, CW2217B is a single-cell lithium battery fuel gauge chip for the system side. It uses an internal high-precision ADC to collect the real-time voltage, current and temperature of the battery, and combines it with a built-in battery model to accurately calculate the remaining battery capacity (SOC). The chip uses a WLCSP package with a size of only 1.58x1.53mm, an operating current as low as 12µA, a current sensing resistor as low as 1mΩ, and can also record the number of battery charge and discharge cycles (Cycle) and calculate the battery's health status (SOH).

Xinhai Technology's BMS product was launched in 2019, with small batches in 2020 and then large-scale supply. At present, Xinhai Technology's single-cell BMS chip has achieved large-scale shipments, which are used in consumer electronics such as mobile phones. In addition, the shipments of its new 2-5-cell BMS also increased significantly in the first quarter of 2024. Among them, the 2-4-cell BMS chip CBM8580 has been recognized by many customers in application scenarios such as laptops, power tools, and sweeping robots. In 2023, the chip will enter the mass production introduction stage for many domestic brand customers.

For example, in the CBMX58X series, CBM8580 is a single-chip fully integrated solution based on 2-4 series lithium-ion or lithium-polymer battery packs. It can provide power monitoring, protection and authentication functions for 2-, 3- and 4-cell series lithium battery packs, and can be widely used in laptops, medical equipment, power tools, sweeping robots and other scenarios.

JWATE's overall business is in a rapid growth stage, and BMS-related businesses are also developing. The company continues to increase R&D investment, enrich product lines, meet the needs of different customers, and gradually expand its share in the domestic market. Its 13-string low-system cost analog front-end chip has been recognized by many customers in the power tool and two-wheeler markets.

For example, the lithium battery management system solution launched by WPG Group based on Nationwide Technology's N32L406 and JW3376 and JW3330 chips from JWHITECH is applied to electric bicycles. The lower board of the solution integrates JW3376 and JW3330 chips from JWHITECH as well as modules such as balancing circuit, charge and discharge control circuit, and temperature acquisition circuit. It can monitor 11-16 series of lithium batteries and lithium iron phosphate batteries in real time, and has overvoltage/undervoltage protection, high/low temperature protection, circuit breaker protection, overcurrent protection and other functions, which can effectively improve the safety and service life of electric bicycle batteries.

Automotive BMS, it is difficult to make it domestically

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.