iso-BTC | Battery testing, isothermal calorimeter - H.E.L Group

iso-BTC | Bench-top, battery performance testing, isothermal calorimeter

The iso-BTC (Battery Testing Calorimeter) is an isothermal calorimeter designed for the characterization of thermal behavior and electrical performance of battery cells under normal and extended use conditions. It supports a range of adaptors which allows a wide range of cell formats to be analyzed.

The iso-BTC supports the full integration of a charge-discharge unit, allowing for the repeated, automated cycling of battery cells under a range of operating conditions, while concurrently recording both the battery’s electrical performance and the heat evolved.  It can also conduct accelerated aging tests, allowing the effect of battery aging on cell performance to be investigated. Battery chemistry, electrode composition, and battery cell type can also be investigated within cell development using the iso-BTC.

Thermal mapping (multipoint temperature measurement) allows the user to identify regions of a battery that generate greater thermal energy to be highlighted.  Along with the thermal behavior characterization of the battery cell over a range of temperatures and (dis)charge rates, this information can be used to inform effective and targeted thermal management strategies within the battery module and pack.

Performance Testing


Characterize differences in cell performance

  • Battery chemistry, electrode composition, type of battery cell, and battery age all influence battery performance. The iso-BTC enables the impact of these factors to be investigated during the development of new cells. The data generated on how battery efficiency, (dis)charging capacity, and heat evolved vary with temperature, and (dis)charging rate can be used to model battery performance and enhance understanding of battery behavior for cell development.


Characterize cell for Quality Control

  • Battery attributes, such as battery efficiency and heat evolved, at specified temperatures and C-rates, can be used to characterize the battery performance. These defined characteristics can be used in Quality Control for both cell manufacturers to demonstrate a stated performance, and for battery integrators to check cell performance downstream. The data from an iso-BTC can enable these characteristics to be determined.


Determine thermal management

  • Under normal use, heat is absorbed and evolved during the charging and discharging cycles of a battery cell. In addition to this, cells within a module may not exhibit uniform properties upon cycling. The potential imbalance this causes, may trigger a safety hazard and affect battery performance.
  • Without careful management, this self-heating can result in overheating and trigger a thermal runaway. The packing and physical arrangement of cells within a module or pack are essential in governing heat transfer. Therefore, it is important to characterize the thermal behavior of the cells, modules, and packs over a range of temperatures and (dis)charge rates, as the data generated can be used to inform effective thermal management.
  • The iso-BTC also supports thermal mapping during testing to highlight regions of the battery, which generate greater thermal energy levels. This information can also be utilized in the implementation of targeted thermal management strategies.


Find out more in our guide Solutions in Battery Technology Testing: Hazard screening, safety testing and performance characterization

Type of Test

  • Performance testing
    • Characterizing performance under normal and abnormal use.
    • Aging and lifetime performance testing.
  • Battery behavior as a function of charge/discharging rate and temperature
    • Heat release profiles.
    • Battery efficiency profiles.
    • Battery charging/discharging capacity profiles.


Battery/Sample Size

  • Coin cells, small pouch cells, and cylindrical cells. Battery adaptor selection for testing on cylindrical cells available.
  • Maximum chamber volume 250 mm wide, 250 mm deep, 80 mm high
    • Test sample volume will include any necessary adaptor volume.


Temperature Control

  • -20 °C to 90 °C as standard
  • Optional: sub-ambient temperatures starting from -40 °C


Intelligent Software Control and Analysis

  • labCONSOL software control enables regular data logging, multi-step recipes, parameter control, and feedback loops. The software adds a responsive intelligence to the iso-BTC system and still delivers an intuitive interface that needs only minimal training to run quickly.


Safety Features

  • Automatic, user-configurable event detection and shutdown procedures, to ensure user safety
  • N2 purge for when operating under sub-ambient conditions
  • Multipoint sample temperature measurement
  • Automatic hardware and software fail-safes are installed on every system

Application Notes:


On-Demand Webinars:





  • Heat Wait Search Video Using H.E.L Battery Testing Calorimeters (BTC)
    • With The H.E.L BTC 130 the maximum temperature of the environment which results in a battery thermal explosion that can be predicted by placing the sample in the BTC and performing well-established adiabatic tests. This involves stepwise heating, followed by a wait-and-search period that can be used with cells and large battery packs alike to determine the maximum safe operating temperature.


Download our latest battery performance and safety testing brochures and specification book


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Specification Book Hazard screening, safety testing and performance characterization solutions Battery Performance and Safety Testing

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