Wireless Battery-Management System Untangles EV Batteries

Battery packs in electric vehicles (EVs) often use complex wiring to collect data about their safety and performance. Heavy-duty copper wire is required to make it reliable enough for automotive use, resulting in a bulky labyrinth of cables and connectors.

Wireless battery-management systems (wBMS) are becoming a trend in commercial EVs because they can unravel a lot of that wiring, said Jerry Shi, general manager of EV/HEV system engineering and marketing at Texas Instruments (watch the video above). By eliminating heavy cabling and simplifying assembly, a wBMS can help increase the range of EVs while reducing the development costs associated with them.

The Case for Wireless Connectivity in a BMS

As the brains of the battery pack, a BMS typically has access to cell voltages, pack current, and a limited number of temperature sensors. From these and other parameters, it can estimate and maximize the runtime of the battery pack as well as prevent conditions such as overcharging, undercharging, or overheating that may lead to premature failure or safety hazards.

To gather data, the battery cells are grouped into modules. Each module has a cell supervisor unit (CSU) that tracks cell voltages, measures temperature, and performs cell balancing.

These units are wired together and connected to the main MCU that regulates the larger EV battery pack. This adds up to pounds of wiring, which is a drag on range, price, and safety, and the cables take up space that could be filled by more battery cells. The wiring also adds to the complexities of assembling the battery pack, requiring a qualified labor force to manually plug in connectors. The cables and connectors are both common points of failure, and repairs can be expensive.

Replacing heavy battery-management wiring with high-reliable, secure wireless connections could cut down on an EV’s overall weight, boosting driving range. A wireless BMS could also boost the amount of energy a battery pack can hold by creating more space in the EV for energy storage.

Moreover, it can eliminate the complexity associated with routing a labyrinth of cables and the cost of repairing them when they fail. A wBMS is more modular, too, giving automakers the ability to easily scale batteries up or down for various models.

The main challenge in eliminating wires from the BMS is ensuring the reliability and robustness of wireless connections. Reliability, latency, and throughput are all key characteristics in a BMS because it must be able to capture voltages, currents, and temperature in real-time so that it can prevent short circuits or other faults from escalating into thermal runaway or fiery explosions.

Many players in power-management ICs, including Analog Devices, Infineon, and Renesas, are using different approaches to solve these problems. For instance, NXP is adopting ultrawideband (UWB) wireless signals to rival the reliability of wired connections.

TI addresses these issues with a proprietary time-slotted, frequency-hopping protocol that runs on its CC2662R-Q1 wireless MCU. The system is narrowband, operating in the same 2.4-GHz bands as Bluetooth LE, but it supports high network availability of more than 99.999%.

Technically, one of the main concerns with a wBMS is the RF link budget. The metal enclosure of the battery pack as well as the cells and wiring inside of it introduces many reflective surfaces for wireless signals, Shi said in an interview with Electronic Design at CES 2026.

This means these transmissions may reach a receiving antenna by multiple paths, resulting in distortion and fading that adds to RF channel path loss. On top of that, interference can come from other wireless systems in the EV using the same wireless band.

To mitigate these issues, TI said it uses adaptive channel-selection algorithms in its wireless MCU. If one channel is overcrowded or overly noisy, TI’s wireless protocol hops to a different frequency in the 2.4-GHz band to avoid it. Dedicated time slots provide high throughput and low latency to protect data from loss or corruption. It also enables multiple battery cells to send voltage and temperature data to the main MCU with an RF link budget of 103.6 dB and a network packet error rate of less than 10^-7.

Inside A Wireless BMS: Battery Cell Monitoring Meet Wireless Connectivity

So, how is this implemented? At the pack level, the CC2662R-Q1 is located within the battery control unit (BCU), where it works with the main battery controller responsible for monitoring the state of charge (SOC) and the state of health (SOH).

At the cell level, the CC2662R-Q1 is designed to be paired with the BQ79x1x-Q1, TI’s battery-management IC primarily used for monitoring the voltage in each cell with ±2-mV accuracy. Both devices can be used to achieve system-level ASIL D safety.

In a 400-V battery composed of 96 cells, for example, eight cell supervisor units could monitor 12 cells each, with a total of eight BQ79616-Q1 chips collecting data and eight CC2662R-Q1 devices sending it wirelessly to the BCU. The wireless MCU isolates individual cell-monitoring units, eliminating the need for, and cost of, daisy-chain isolation components. TI said the wireless MCU also comes with a wide range of security features so that automakers can reduce the risk of cyberthreats.

On top of that, the wireless BMS is also scalable to stay ahead of the shift to bigger battery packs. The deterministic protocol can transfer data at up to 1.2 Mb/s, enabling automakers to create a battery module using a single wireless MCU connected with multiple battery monitors for different configurations, such as 32-, 48- and 60-cell systems. The system can stay up to 100 nodes with latency of less than 2 ms per node and time-synchronized measurements across every node.

One of the other aspects of the CC2662R-Q1 is that it can help enable second-life EV batteries. Such batteries have reached the end of their automotive lifespan, but they still maintain a residual capacity of about 70% to 80% and thus can be useful for grid-connected energy storage systems (ESS).

The MCU’s radio runs a common software stack — TI’s SimpleLink SDK. It gives customers the ability to adopt TI’s protocol in the EV battery pack and then adopt non-TI protocols such as Bluetooth LE for the second-life phase of the cells.

While proprietary, TI said there are no software licensing fees for its wireless BMS protocol. Since it can avoid multipath interference, the wBMS also helps reduce software complexity and development time.