EIS Analyzer 2.4.0 — Dynamic EIS, a Rebuilt Fitting Experience & Richer Export

EIS
Batalyse EIS Analyzer 2.4.0 — fit results across multiple circuit models

EIS Analyzer 2.4.0 is here. This release brings better fitting-result management, a brand-new Dynamic EIS workspace, a rebuilt fitting experience, and far richer Origin export — plus new instrument support (Maccor, Bio-Logic GEIS, three-electrode), smarter constrained fitting, and an in-app guide in 10 languages.

The Batalyse EIS Analyzer is a desktop application for analyzing Electrochemical Impedance Spectroscopy (EIS) data from batteries, fuel cells, supercapacitors and electrochemical sensors. It covers the complete workflow from raw data import through equivalent-circuit fitting, Distribution of Relaxation Times (DRT) analysis and Kramers-Kronig validation to Origin (.opju) and CSV export. Version 2.4.0 sharpens every one of those stages and opens a new chapter for time-resolved, operando diagnostics.


A rebuilt Fitting experience

Manage, compare, and constrain fits without ever losing your place. Toggleable result chips let you display and compare several files or sweeps side by side; your selection persists across re-fits, and a mirrored picker sits in the fit-vs-data plot header.

Three EIS files fitted with the same Two RQ + Warburg model, side by side
Compare fits across EIS1–EIS3.DTA side by side, each with χ² and per-parameter errors.

A new Fit Results grid arranges one card per fit on a cycle × model layout, with per-sweep fit history that survives reload, the fit date and time on every card, in-place sweep renaming, and a “Show all” for runs beyond 20 cycles.

A grid of fit-result cards comparing four circuit models per EIS file
One card per fit across every model — Inductor + TLM, TLM Simplified, Randles, Two RQ + Warburg — with the latest fit flagged and full history retained.

The new Parameter Trend view plots any fitted parameter (or χ²) across your sweeps, with a cycle-aware x-axis (cycle major, sweep minor) and a voltage x-axis mode. You can also toggle individual charge/discharge cycles on or off and overlay cycles by within-cycle position — one curve per circuit model, plus per-electrode curves for three-electrode data.

Parameter Trend view plotting series resistance R_s across sweeps with error bars
Track any fitted parameter — here Rs — across sweeps, with error bars and a cycle-aware x-axis.

Pick your fitting frequency range by clicking directly on the spectrum — free-click anywhere, with a log-space snap to the nearest data point — using a full-width Bode/Nyquist picker that is also available inside the DEIS Fit-all dialog.

Bode and Nyquist plots with draggable min and max frequency bounds
Click two points on the Bode or Nyquist plot to set the min & max fitting frequency.

Under the hood, constrained fitting — bounds, fix/free, shared parameters across sweeps, and expressions — now lives in one unified table, with DRT-guided initial guesses and multi-start optimization. And both Auto-Analysis and Fitting show a live progress overlay that can be cancelled mid-run.

Initial parameter table with Value, Fix, Shared, Min, Max and Expression columns
Fix or free each parameter, bound the search range, share values across sweeps, or link them by expression.

Dynamic EIS (DEIS) — a new workspace

Dynamic EIS is a brand-new workspace, currently in development — a dedicated home for sweep groups and time-resolved diagnostics. Build and manage your DEIS sweep groups on a dedicated tab, then send them straight to trajectories, DRT, stationarity checks and diagnostics.

New DEIS group dialog on the Dynamic EIS tab, selecting ten SOC spectra in order
Group multiple spectra into a DEIS sweep from the dedicated Dynamic EIS tab.

Import raw time-series from custom potentiostats and the Analyzer recovers the impedance for you: it removes slow drift, windows the signal, and extracts Z(ω) at the excitation frequencies, with no manual pre-processing. Coherent averaging over repeated cycles suppresses noise (∝ √N), and built-in signal-quality checks flag non-linear distortion and residual drift before they corrupt a fit.

The heart of operando battery diagnostics is the parameter trajectory: track any fitted circuit parameter (Rct, Rs, capacitance, …) versus SOC, time, or cycle number, and watch how the interface evolves through a charge/discharge — with error bars, a compact multi-column legend, and two-group overlay comparison.

DEIS trajectory plot of all fit parameters along the sweep versus state of charge
Every fit parameter tracked along the sweep vs. SOC — click any point to inspect that member’s spectrum and fit.

DRT, frame by frame: Distribution-of-Relaxation-Times analysis (with automatic regularization) plus a DRT-evolution heatmap across the whole sweep separate SEI, charge-transfer and diffusion processes and let you watch each one shift as the cell cycles. A one-click Auto-Analyzer runs the full pipeline — DRT, fit, Kramers-Kronig, features — across every sweep with live progress.

SOC is computed automatically by coulomb counting, with per-member drill-down: click any trajectory point to inspect its spectrum and residuals. You can also enter SOC, current, time and cycle per spectrum by hand.

Edit metadata dialog with SOC, current, time and cycle fields per spectrum
Enter SOC, current, time and cycle per spectrum — or compute SOC from current by coulomb counting.

A dedicated lithium-plating onset diagnostic flags the onset of plating as an anomalously sharp drop in the charge-transfer resistance Rct (or a chosen fit parameter) along the sweep vs. SOC or time, with a configurable drop threshold and a clear pass/fail readout. When you’re done, bundle a whole sweep group into a single self-contained .batalyse file to save and share.

Lithium-plating onset diagnostic plotting R_1 against state of charge
Lithium-plating onset diagnostic — flags an anomalously sharp drop in Rct (or a chosen parameter) along the sweep vs. SOC or time.

Broader instrument support

More of your raw files load directly, with sweeps and metadata intact:

  • Maccor — EIS text and V2 binary FRA spectra, plus numeric file extensions (.001, .002, …), with the rich binary header surfaced on upload.
  • Bio-Logic GEIS — auto-import preserves all sweeps; cycling data feeds the Non-EIS and Polarization tabs.
  • Three-electrode — handling with correct impedance sign-correction and per-electrode output.

Richer export

Take publication-ready results straight into Origin or a spreadsheet:

  • Origin (.opju) — every fit (current + history) with matching colors and model labels, Bode plots overlaying fit curves, a Kramers-Kronig Nyquist graph, and parameter trends plotted against the real trajectory coordinate (SOC / voltage / cycle), one point per sweep.
  • CSV / XLSX — per-parameter errors and units, dated filenames, and per-sweep graphs in the export ZIP.

Work in your own language

The in-app guide is now fully translated into ten languages — English, German, Spanish, French, Italian, Portuguese, Japanese, Korean, Chinese and Hindi — including a step-by-step Dynamic EIS chapter.

Language selector showing ten flags: EN, DE, ES, FR, PT, JA, ZH, KO, HI, IT
Switch the in-app guide between ten languages.

Questions, feedback, or run into anything while trying the new release? Write to us at support@batalyse.com — we’d love to hear how it works with your data.

Batalyse Newsletter

Register now and don't miss any news!

    By registering, you agree to our privacy policy.

    News

    Interested in our product strategy and current work topics? Here you go.
    View all
    Batalyse EIS Analyzer 2.4.0 — fit results across multiple circuit models
    EIS
    5 min read
    EIS Analyzer 2.4.0 — Dynamic EIS, a Rebuilt Fitting Experience & Richer Export

    EIS Analyzer 2.4.0 brings a brand-new Dynamic EIS workspace, a rebuilt fitting experience with side-by-side comparison and parameter trends, far richer Origin export, new instrument support (Maccor, Bio-Logic GEIS, three-electrode), and an in-app guide in 10 languages.

    Batalyse EIS Analyzer 2.2.2
    EIS
    5 min read
    EIS Analyzer – Major Version Update

    Over the past months the EIS Analyzer has evolved from a Streamlit prototype into a full-featured native application. This article summarizes the most significant improvements across the 2.0, 2.1 and 2.2 release series.

    Collect Data Analysis EIS Mind
    5 min read
    BaetterAI: AI Meets Battery Research 🔋⚡

    We are excited to announce the launch of BaetterAI – our joint research project funded by the German Federal Ministry for Research, Technology and Space (BMFTR), developing a Universal Data Processing Tool for AI-based battery research.