Produced by ZhiNeng Auto
General Motors (GM) was the first automaker to adopt a wireless management system in its automotive battery systems.
As this technology has been implemented for nearly five years, the benefits and value it has brought are not yet obvious. Just when this technological direction seemed to be in jeopardy, Tesla and Hyundai and Kia stepped in, prompting a re-evaluation of this technological path.
Background: Inside the battery pack of an electric vehicle (EV), the voltage of every single cell must be monitored. Therefore, wires are drawn from each cell to the acquisition unit. The connectors are piled together, taking up space, adding weight, and over time, posing a risk of aging and short circuits.
The wireless BMS (wBMS) simplifies this process. Each cell module achieves a very short connection, collecting data locally and equipped with its own transmitter for wireless communication. The battery main control unit only needs a single receiver. Theoretically, this significantly reduces the wiring harness.
In September 2020, ADI (Analog Devices) launched the industry's first wireless battery management chip. General Motors was the first automaker to adopt it, implementing it on the Ultium platform.
Part 1: General Motors: The Pioneer Who Took the Plunge and Faced Teething Issues
At the 2020 launch event, GM presented a comparison showing that, compared to the previous generation, the current design reduces the wiring harness by 90% (compared to centralized designs) and reduces the volume by 15%. The core chips are the ADBMS6832M (18 channels) and ADBMS6833M (16 channels).
GM mass-produced this on the Ultium platform, with the LYRIQ being the first mass-production vehicle equipped with it.
Zhihu's Car Teardown Lab conducted a series of extreme tests on the Ultium battery pack: in an interference environment with 28 mobile phones dialing simultaneously, the wBMS reception rate was 100% with zero packet loss; under the suppression of two signal jammers, the reception rate remained at 99.47%.
The principle is not complex. Each module transmits independently, using a Mesh network topology for redundant backup. If a single module fails, adjacent modules automatically relay the transmission. Coupled with adaptive frequency hopping to avoid interference bands, GM's engineers have addressed the long-standing concern about wireless instability through engineering solutions.
However, being the first mover also means encountering the first pitfalls.
In the United States, this system has experienced some teething issues. The 2023 Lyriq faced delivery delays due to software and integration problems, with some vehicles requiring reflashing or even module replacement before delivery; the earliest batch of SoCs reported inaccuracies that had to be fixed via OTA patches.
The NHTSA issued two recalls: 23V-367 involving the Hummer EV and Lyriq traction batteries, and 25V-483 involving the Lyriq and Vistiq battery packs.
Both recalls involved hardware issues at the battery pack level. The 2024 Blazer EV was also briefly halted from sales due to infotainment and BMS software issues. In 2026, a class-action lawsuit even emerged concerning the high-voltage system and BMS of the Lyriq.
The wireless architecture itself is not to blame for these pitfalls. The price of being a first mover is the integration and debugging of the entire vehicle software stack with the first-generation platform. This tuition fee had to be paid sooner or later. Given the changes in U.S. subsidy policies, GM's architecture does not seem to be a popular buzzword anymore.
Part 2: Hyundai and Kia: The Silent Followers
The actions of the South Korean automakers have been faster than the public perceives.
On January 27, 2026, Hyundai Mobis obtained two FCC certifications on the same day: NBCMUV01 for the Cell Monitoring Unit (CMU) and NBBMUV01 for the Battery Management Unit (BMU). Operating on BLE 2.4GHz, the transmission power is kept very low, at 5.358 milliwatts for the CMU and 3.656 milliwatts for the BMU.
The debut model points to the Genesis GV90, expected to be released in September 2026, with batteries supplied by Samsung SDI. If all goes smoothly, this will be the first implemented wBMS by a South Korean automaker.
Kia's motivation is more driven by compliance.
The EU will mandate the implementation of battery passports in 2027, requiring full traceability of data for every battery from production to recycling. The wBMS is naturally suited for real-time uploading of cell-level data. Once the EU tightens this regulation, automakers will have no choice but to follow.
Kia is testing cell-level monitoring solutions on the EV3, which is an attempt to introduce the wBMS, allowing for system-level integration.
Part 3: Tesla: Car Manufacturing Is No Longer the Main Business, Technology Is Still Advancing
Tesla is also proceeding in an orderly manner, with its next-generation BMS fully transitioning to wireless.
From February to April 2026, Tesla consecutively obtained FCC certifications:
◎ 2AEIM-1900020 (BCU Battery Control Unit)
◎ 2AEIM-1930238 (BMB Battery Monitoring Board)
Communicating via BLE 2.4GHz with a power of around 8mW, it features a distributed architecture similar to Hyundai Mobis's solution, enabling wireless transmission between the BMU and CMU.
The Tesla BMB has a transmission power of 8.61mW, while Hyundai Mobis's is only 3.656mW, making Tesla's more than twice as high. The certification documents for both the BCU and BMB include "ADI_Declaration_Document_Tesla". ADI refers to Analog Devices, indicating a high probability that Tesla's BMS analog front-end is supplied by ADI.
As for the wBMS, General Motors gave it a try. Of course, Chinese automakers, by adopting CTP (Cell to Pack) and CTB (Cell to Body) designs, have already highly streamlined their wiring harnesses, so the benefits brought by wiring harness optimization are not that significant.
From module assembly to CTP, eliminating the plug-in process at the assembly level has little impact. The current starting point may revolve around the traceability requirements of battery passports, and costs have also decreased now.
ADI is currently the most widely implemented wBMS chip manufacturer. GM's Ultium uses its solution, and ADI's name also appears in Tesla's FCC documents.
NXP and TI (Texas Instruments) have also developed solutions for wBMS; it remains to be seen whether automakers will adopt them in the future. Dukosi specializes in cell-level wireless monitoring, and domestic automakers are also developing their own solutions.
Summary
Driven by cost reduction pressures and technological iterations, battery systems are clearly moving in a cost-oriented direction. Once the net cost pressure is pushed to the extreme, the technological direction may return to its original track. This time, Tesla is quietly taking action on this, which also reveals some interesting insights.