Enabling Lab-Grade DCIR and EIS Accuracy in Real-World Battery Systems
Battery designers are continually developing methods to achieve deeper insights into the condition of battery cells to achieve greater performance, safety and extend the working lifetime.
Bringing greater intelligence to every cell, Dukosi is demonstrating on-cell DCIR and EIS advanced measurement capabilities, enabling richer diagnostics that can feed into more accurate State of Charge (SoC), State of Available Power (SoP), and State of Health (SoH) estimation.
DCIR vs EIS – Which is right for you?
When deciding between DCIR or EIS, battery designers must choose the right balance between measurement speed, implementation cost and the necessary diagnostic depth for their application. However, it’s not just about ticking the acronym box on a new battery pack, data quality is paramount, and performing advanced measurements directly on the cell is clearly an advantage.
Bringing Fast, Accurate, Cost-Effective DCIR Measurements into Battery Systems
DCIR is a valuable indicator of the internal condition of the cell. It can be used with all players in the value chain from cell manufacturers identifying production outliers or defects, to enabling EV owners or BESS operators to monitor degradation throughout a battery’s lifetime.
An example of the relationship between a cell’s State of Health vs internal resistance over a period of use
Conventional DCIR measurements are typically performed at the pack level, where busbars, connectors and wiring introduce additional resistances that reduce measurement accuracy. Dukosi overcomes these limitations with its chip-on-cell architecture, performing DCIR measurements directly at each cell, allowing it to isolate and evaluate the internal resistance exclusively.
By eliminating pack-level parasitic resistance and measuring as close as possible to the cell terminals, Dukosi’s DCIR delivers highly accurate, repeatable results in real battery systems on par with lab-grade equipment.
The implementation requires no external excitation hardware, simplifying system BoM and cost, with measurements taking just one second. On-chip processing then calculates the internal resistance value, which is communicated deterministically to the BMS processor via C-SynQ®. The result is highly accurate and repeatable per-cell resistance data that improves SoP and SoH estimations, enabling early fault detection for safer, more reliable battery operation without increasing system complexity.
Bringing Lab-Grade Accuracy EIS to Every Cell
Dukosi EIS can equal or better lab equipment results
While DCIR provides a conveniently fast indication of the internal cell condition, Electrochemical Impedance Spectroscopy (EIS) can provide a more comprehensive insight into battery chemistry, ageing and degradation mechanisms.
Traditionally, EIS has been confined to laboratory environments because repeatedly achieving accurate measurements is difficult. While pack-level EIS is possible, its accuracy is affected to an even greater degree by the same issues that affect pack-level DCIR measurement.
The same advantages that Dukosi leverages for DCIR are enabled by on-cell EIS: highly accurate and repeatable per-cell results, which are achieved by generating the low current measurement stimulus directly from the Dukosi chip, capturing the response locally, and then transmitting complex impedance data via C-SynQ to the BMS processor. Keeping the measurement circuitry at the cell minimizes pack-level errors caused by wiring, inductance and coupling effects, enabling reliable measurements across a wide frequency range and consistently achieving lab-grade accuracy.
However, unlike DCIR implementing EIS is more complex. A full frequency sweep of measurement capture typically takes around 30 seconds, which means BMS designers or application developers need to accommodate a different window of opportunity. Dukosi navigates this limitation by supporting the ability to target specific frequencies to track key data points, so the test time can be significantly reduced. Dukosi’s per-cell EIS provides richer information, offering significantly greater diagnostic capability where deeper battery intelligence is required. This can be useful for greater accuracy in long term health tracking, defect identification, degradation analysis, and predictive maintenance, especially when the data is collated and compared across an entire fleet of in-field batteries.
Higher Quality Advanced Measurements. Better Battery Intelligence.
Advanced per-cell measurements transform battery monitoring from periodic testing into continuous intelligence. By combining accurate and repeatable voltage, temperature, DCIR and EIS data at every cell, Dukosi gives battery developers a more complete understanding of battery behavior throughout manufacturing and operation.
The result is earlier fault detection, more accurate battery models, improved lifetime prediction, outlier detection and better-informed BMS decisions. For battery manufacturers and system integrators, this translates into safer systems, higher performance, reduced maintenance costs and greater confidence throughout the battery lifecycle.
Talk to us about what DCIR and EIS can do for your next generation battery, how to achieve better results, and start your development journey today with Dukosi in your next battery pack.