This chip sees inside batteries. Texas Instruments raises the bar for BESS safety

Texas Instruments is bringing to market a chip that assesses battery cell health far more precisely than standard management systems. The new solution could mark a breakthrough in safety, data reliability, and financing for large-scale battery energy storage systems (BESS).

The flat LFP voltage curve

LFP (lithium iron phosphate) batteries have come to dominate the stationary energy storage market thanks to their long cycle life and strong safety profile. However, they have a significant drawback: a very flat voltage curve in the middle of their state-of-charge range.

As Henrik Mannesson, general manager of Grid Infrastructure and Power Delivery at TI, explained, within this range, voltage readings alone make it difficult to determine whether a lower value reflects permanent cell aging or simply the current state of charge. Standard systems estimate battery state of health by counting cycles rather than using precise models.

EIS on the chip, not outside it

The solution is a technique known as electrochemical impedance spectroscopy (EIS), which involves applying a small current or voltage perturbation to a cell and measuring its internal impedance at different frequencies.

Texas Instruments’ new chip, designated BQ79826Z-Q1, integrates EIS directly into the silicon die. This moves electrochemical diagnostics beyond a passive process and embeds them directly at the hardware level.

As Mannesson emphasized, creating an accurate electrical model of each cell makes it possible to distinguish the effects of state of charge from permanent chemical degradation, such as lithium plating or chemical changes within the material.

A cleaner signal, less hardware

Impedance curves are sensitive to external interference, so Mannesson’s team is working with engineers on the installation’s physical configuration, including wiring, connectors, and internal resistance, all of which affect measurements.

According to TI, integrating the EIS engine onto a single chip produces a cleaner impedance signal delivered directly from the device. This eliminates the need for extensive additional diagnostic hardware.

Manufacturers can therefore run their own proprietary algorithms directly on the raw data, potentially without having to license specialized diagnostic software from third parties.

26 channels and fewer components

Large-scale battery systems are now moving from 52-cell modules to 104-cell architectures. The BQ79826Z-Q1 chip monitors up to 26 cells connected in series—eight more than competing monitoring chips.

For a 104-cell module, this means engineers can cover the entire pack with four TI chips, minimizing component count, board space, and cost per channel.

This simpler architecture, combined with other compliance features, improves both safety and the financial credibility of projects. As Mannesson noted, large-scale energy storage systems are financed by pension and infrastructure funds seeking secure investment returns. Providing reliable data on thermal runaway and cell aging directly enhances a project’s bankability.

When will the first deployments arrive?

Mannesson confirmed that Texas Instruments is currently testing preproduction samples of the new chip, with full-scale volume production scheduled to begin by the end of 2026. Although final integration depends on customers, the first commercial energy storage systems using the new chip could reach the market as early as 2027.

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