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Isothermal Battery Calorimeters

Cutaway image revealing chamber within chamber and conduit connecting inner chamber to exterior of equipment.

Cutaway showing battery in the test chamber, heat flux gauges, isothermal fluid surrounding the test chamber, and outside container with insulation holding the bath fluid and the test chamber. Image: Courtesy of NETZSCH

R&D 100 2013

NREL's IBCs were recognized with an R&D 100 Award, known as the "Oscars of Innovation."

Photo of researchers next to a square metal box (calorimeter test chamber).

Test chamber of the large-volume IBC.

Photo of scientific equipment (interior of calorimeter test chamber) with a boxy battery pack at its center with wires connecting the pack to interior walls of chamber.

The capacity of the large-volume IBC test chamber is 53 times larger than that of other devices on the market.

Photo of rectangular metal box (calorimeter test chamber) with lid secured by screws and a gasket affixed to the top.

The cell/module IBC produces measurements of the same accuracy as the large-volume IBC of smaller-scale components.

NREL's R&D 100 Award-winning Isothermal Battery Calorimeters (IBCs) are the only calorimeters in the world capable of providing the precise thermal measurements needed for safer, longer-lasting, and more cost-effective electric-drive vehicle (EDV) batteries. In order for EDVs hybrids (HEVs), plug-in hybrids (PHEVs), and all-electric vehicles (EVs) to realize ultimate market penetration, their batteries need to operate at maximum efficiency, performing at optimal temperatures in a wide range of driving conditions and climates, and through numerous charging cycles.

NREL's IBCs make it possible to accurately measure the heat generated by electric-drive vehicle batteries, analyze the effects of temperature on battery systems, and pinpoint ways to manage temperatures for the best performance and maximum life. Three models, the IBC 284, the Module IBC, and the Large-Volume IBC, make it possible to evaluate energy devices at a full range of scales.

The World's Most Precise Battery Calorimeters

Development of precisely calibrated battery systems relies on accurate measurements of heat generated by battery modules during the full range of charge/discharge cycles, as well as determination of whether the heat was generated electrochemically or resistively. The IBCs can determine heat levels and battery energy efficiency with 98% accuracy and provide precise measurements through complete thermal isolation. These are the first calorimeters designed to analyze heat loads generated by complete battery systems.

Text version

Calorimeter Specifications
Specifications IBC 284 (Cell) Module IBC Large-Volume IBC (Pack)
Maximum Voltage (Volts) 50 500 600
Sustained Maximum Current (Amps) 250 250 450
Excursion Currents (Amps) 300 300 1,000
Volume (liters) 9.4 14.7 96
Maximum Dimensions (cm) 20.3 x 20.3 x 15.2 35 x 21 x 20 60 x 40 x 40
Operating Temperature (C) -30 to 60 -30 to 60 -40 to 100
Maximum Constant Heat Generation (W) 50 150 4,000

Working with Industry to Fine-Tune Energy Storage Designs

The IBCs' capabilities make it possible for battery developers to predict thermal performance before installing batteries in vehicles. Manufacturers use these metrics to compare battery performance to industry averages, troubleshoot thermal issues, and fine-tune designs.

NREL in partnership with NETSCH Instrument North America and with support from the U.S. Department of Energy is using IBCs to help industry design better thermal management systems for EDV battery cells, modules, and packs. The U.S. Advanced Battery Consortium (USABC) and its partners rely on NREL for precise measurement of energy storage devices' heat generation and efficiency under different states of charge, power profiles, and temperatures.

For more details on the IBCs, see the fact sheet.

Contact

For more information about NREL's energy storage thermal management activities, contact Matthew Keyser, 303-275-3876.