Technology Basics
![Photo of an ultracapacitor.](images/photo_ultracapicitator.jpg)
Electrochemical energy storage devices provide the power for many everyday devices—from cars, trains, and laptops to personal digital assistants and cell phones to utility backups.
![Photo of a battery pack.](images/photo_battery_pack.jpg)
While batteries are the most common type of energy storage device, ultracapacitors provide energy as a quick pulse to a variety of systems. Because these devices are essential in today's world, government, industry, and national laboratories are making significant efforts to improve them. NREL focuses on researching batteries and ultracapacitors for use in conventional and advanced vehicles.