TI Intros 26-Cell Battery Monitor IC With Integrated Smart EIS Engine

This week, at PCIM 2026 in Nuremberg, Germany, Texas Instruments introduced the BQ79826Z-Q1, the trade’s highest-cell-count battery monitor that includes an built-in electrochemical impedance spectroscopy (EIS) engine. Tailor-made for electrical autos (EVs) and industrial power storage methods (ESSs), the gadget brings predictive intelligence, complete information, and real-time diagnostics on to battery monitoring architectures.

The first development of this single-chip monitor is its functionality to trace as much as 26 cells related in collection, delivering eight extra cells per gadget than competing market options. This represents as much as a 44% improve in monitoring channels in comparison with earlier gadget generations.

TI’s new BQ79826Z-Q1 battery monitor IC permits elevated security and efficiency in EVs and ESSs.

To be taught extra in regards to the new gadget, EEPower attended a pre-briefing with Texas Devices spokespersons Wenjia Liu Vice President & Normal Supervisor – Battery Administration Options and Brian Burk Techniques Engineer and Product Supervisor, Battery Monitor Merchandise.

By supporting extra cells per gadget, the monitor considerably decreases the overall variety of parts required inside a high-voltage battery pack. This discount in element density streamlines architectural complexity, reduces required board house, and lowers total system bill-of-materials (BOM) prices with out sacrificing pack high quality or reliability.

“With 26 cells, designers can eradicate a number of displays within the system, streamlining the structure, chopping the invoice of supplies and releasing up that useful board house throughout the system,” mentioned Brian Burk.

Built-in EIS Engine for Inner Cell Diagnostics

Wenjia Liu gave some background concerning the time period electrochemical impedance spectroscopy (EIS) within the context of BMS. “EIS know-how has been round for many years,” she mentioned. “Solely very not too long ago has it grow to be sensible and been utilized at scale in real-world purposes like EVs and ESS.”

“In an oversimplified method, you may consider EIS as a battery’s EKG,” continued Liu. “So as an alternative of simply measuring the floor degree indicators like voltage and temperature, it offers a deeper look into the battery’s inside cell behaviors and permits early detection and predictive insights that conventional sensors weren’t in a position to present.”

EIS know-how is used to investigate chemical state-date from contained in the battery cells, enabling early fault detection.

By analyzing wealthy chemical-state information from contained in the cells, the system can detect inside fault circumstances a lot sooner than standard displays. This allows an early warning system for extreme automobile and system hazards equivalent to thermal runaway. These steady diagnostic advantages lengthen throughout the grid-to-gate ecosystem, aiding engineers in monitoring the state of cost (SoC) and state of well being (SoH) of enormous battery installations required to satisfy the scaling energy calls for of synthetic intelligence information facilities.

“With TI’s EIS know-how, engineers can now scale back the variety of temperature sensors, and truly get improved temperature accuracy by utilizing superior battery core temperature readings,” says Burk.

In response to its technical specs, the embedded good EIS engine achieves an impedance accuracy of 1% when using a 1 A excitation present and a 200 µΩ cell impedance. The engine helps an excitation frequency vary spanning from 0.01 Hz to three.5 kHz, permitting for each native and world excitation topologies.

To make sure exact information correlation, the gadget maintains an inside present and voltage (I/V) synchronization of lower than 5 µs from gadget to gadget. In the meantime, the EIS measurement routine is 5 occasions sooner than earlier architectures, permitting the chip to ship extremely responsive purposeful security voltage readings per cell.

Excessive-Precision Sensing and Scalable Communication Topology

To handle vary nervousness for EV drivers, the monitor permits extremely exact temperature and state-of-charge estimations. The BQ79826Z-Q1 delivers a cell voltage accuracy of lower than 2 mV throughout a full automotive temperature vary of –40°C to +125°C. It depends on a devoted analog-to-digital converter (ADC) per channel alongside ultra-low noise filtering.

The monitor helps an absolute most voltage score of 143 V, with a cell measurement vary of 0 to five.5 V and a busbar measurement functionality of –2 V to 2 V on each channel besides the primary channel.

For prime-voltage battery arrays, the BQ79826Z-Q1 options an upgraded daisy-chain interface that helps a 2 Mbps bus velocity, which might scale as much as 4 Mbps utilizing twin SPI modes. As much as 128 units might be stacked collectively in stack, ring, multidrop, or split-ring topologies by way of transformer or capacitor-only isolation boundaries.

This interface maintains a device-to-device computerized communications balancing synchronization of underneath ±5 µs, yielding a Fault Detection and Isolation Time (FDTI) of lower than 100 ms for 800 V packs or configurations with 250 cells. Extra data is obtainable within the BQ79826Z-Q1 data sheet.

The BQ79826Z-Q1 is designed to be scalable, working throughout completely different module sizes, battery chemistries and mechanical designs.

When paired with the BQ79881-Q1 pack monitor and an non-obligatory communications bridge, these parts kind a versatile chipset that permits engineers to design a single platform and deploy it throughout various module sizes and battery chemistries.

“This scalability offers engineers the flexibleness to design as soon as and deploy all over the place,” says Liu. “This offers financial savings in engineering overhead, drives shorter time to market, and in addition decrease whole BOM price.”

Security, Balancing, and Energy Administration Options

Developed underneath strict ISO 26262 tips, the BQ79826Z-Q1 complies with Automotive Security Integrity Degree D (ASIL-D) necessities to supply a dependable path to purposeful security. Safety mechanisms embrace autonomous {hardware} monitoring for cell over-voltage, under-voltage, over-temperature, and under-temperature circumstances, complemented by open-wire detection and twin on-chip die temperature sensors.

To take care of cost equilibrium throughout the cell stack, the gadget incorporates passive cell balancing by way of built-in FETs. It helps as much as 300 mA of strange/even balancing present with programmable pulse-width modulation (PWM) management and computerized diagnostics throughout balancing routines.

System energy is optimized throughout three predominant working modes: an lively mode consuming lower than 5 mA, a low-power monitoring sleep mode drawing as little as 20 µA, and a complete shutdown state that consumes lower than 10 µA.

For exterior system interfaces, the monitor offers 20 multi-purpose GPIO pins that deal with temperature sensing (by way of NTC/PTC thermistors), basic voltage measurements, and a devoted sensor monitor with a peak-hold and strain threshold detector. All the system is housed in a 100-pin HTQFP package deal measuring 12 mm x 12 mm with an built-in bottom-side PowerPad for optimum thermal efficiency.

Market Availability

In response to Texas Devices, the BQ79826Z-Q1 represents a major step ahead in battery administration intelligence. Preproduction portions of the monitor are at the moment accessible on TI.com, with full manufacturing volumes anticipated by the tip of 2026.

To help improvement, TI offers complete analysis modules (EVMs) and reference designs, that are being showcased alongside different high-voltage energy improvements on the PCIM 2026 Expo and Conference this week in Nuremberg, Germany.

All photographs used courtesy of Texas Instruments.