National Renewable Energy Laboratory

Energy Storage

Laboratory Capabilities

Photo of NREL's Energy Storage Laboratory.

NREL's Energy Storage Laboratory.

Welcome to our Energy Storage Laboratory at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. Much of our testing is conducted at this state-of-the-art laboratory, where researchers use cutting-edge modeling and analysis tools to focus on thermal management systems—from the cell level to the battery pack or ultracapacitor stack—for electric, hybrid electric, and fuel cell vehicles (EVs, HEVs, and FCVs).

The laboratory houses a unique calorimeter that measures battery and ultracapacitor performance over a wide range of temperatures and sizes. Engineers use thermal imaging equipment to capture a battery's or ultracapacitor's infrared fingerprint to diagnose its behavior. They also assess the thermal and moisture management properties of fuel cell systems. Our capabilities enable world-class research in energy storage thermal management, battery and vehicle modeling and simulation, and energy storage from a vehicle systems perspective.

Click the thumbnail image to see a larger scale view of the laboratory's layout.

See the laboratory's layout and read more below to learn how our unique equipment and capabilities can meet your energy storage needs.


Equipment

Large conduction calorimeter

Accurate heat generation data from battery modules and ultracapacitor stacks are essential to properly design thermal management systems. Our customized large conduction calorimeter measures a battery's or an ultracapacitor's performance for heat generation at various rates, temperatures, states of charge (SOC), and heat capacities.

Content on this page requires a newer version of Adobe Flash Player.

Get Adobe Flash player

Flash Content for Screen Readers

Calorimeter Text Version

Welcome to NREL's Energy Storage Laboratory, located in Golden, Colorado, where we use high quality equipment to conduct battery thermal management, modeling and analysis.

NREL's Energy Storage Lab has a state-of-the-art calorimeter (cal-oh-RIM-e-ter), which measures heat generation from energy storage devices. Data from the calorimeter helps researchers design thermal management systems for hybrid electric, electric, and fuel cell vehicles. This information enables the transportation industry to improve the cost and efficiency of advanced vehicles.

It tests energy storage devices, such as batteries, over various charge/discharge cycles and drive cycles, while measuring heat losses as low as 5 milliwatts.

The calorimeter consists of an isothermal bath and a cavity test chamber. The bath has an operational temperature range from -30 degrees Celsius to +60 degrees Celsius.

A battery is placed in the test chamber and connected to a power supply.

The schematic shows the test chamber's heat flux gauges, surrounded by isothermal bath fluid. The heat flux gauges measure the rate of heat generation from the battery. These gauges can detect heat generation rates from 5 milliwatts to 100 watts.

A computer measures the electrical power going into the battery as well as the heat being released from the battery.

The bottom (or red) graph shows the battery's power profile over time. The top (or green) graph tracks how much heat is released from the battery over time. When the electrical power to the battery is turned off, heat generation stops and the battery cools back down to the temperature of the surrounding bath.

This heat generation and efficiency data from the calorimeter allows NREL researchers to help the transportation industry improve batteries and thermal management systems for advanced vehicles.

Bitrode battery/ultracapacitors cyclers

The Bitrode cyclers in the lab are designed specifically for hybrid electric, electric, and fuel cell vehicle (HEV, EV, and FCV) battery and ultracapacitor pack testing. Their voltages range from 0-420 volts with a maximum current output of 530 amps. These cyclers can meet the most demanding drive-cycle profiles. They are integrated with the calorimeter to measure heat generation under various charge/discharge cycles and for power profiles from vehicles.

Environmental chambers and isothermal baths

Accurate temperature measurement and control are critical for testing energy storage systems. Our environmental chambers and isothermal baths can control temperature from -35°C to 100°C with an accuracy of 0.1°C.

Infrared thermal imaging equipment

Check out these time-lapse battery thermal images (AVI 4.5 MB)!
Use Windows Media Player 10 to view this file. Download Media Player.
Engineers use thermal imaging equipment to capture an energy storage device's infrared fingerprint to evaluate and diagnose the behavior of energy storage systems in advanced vehicles.

Alternating current power amplifier

This unique, custom-made alternating current (AC) power amplifier enables us to test energy storage preheating concepts for vehicles that operate in cold climates, and to evaluate the effects of high-frequency harmonics on battery life.