Top 10 Reasons for Using Ultracapacitors in Your System Design - Maxwell Technologies - #1

Historically, the use of a single energy device to satisfy the entire power specification of an application required designers to either design for power (at times providing excess energy), or design for energy (at times providing inadequate power). Ultracapacitors, also known as electrochemical double layer capacitors, have unique characteristics when compared to other energy storage devices. By leveraging these unique features, you have more freedom when designing your power system. The high performance characteristics of Maxwell Technologies' BOOSTCAP® ultracapacitors allows you, the system designer, to develop hybrid power system solutions that cost less and perform better than non-hybrid solutions.

The benefits of using ultracapacitor technology in your designs are quite extensive. Here are ten reasons why you should consider using ultracapacitors in your power systems:

BOOSTCAP ultracapacitors are highly efficient components. Their coulombic efficiency (defined as the total charge removed divided by the total charge added to replenish the charge removed) is greater than 99%, even at very high currents, meaning that little charge is lost when charging and discharging the ultracapacitor. Round-trip efficiency is also very high, due to the low equivalent series resistance (ESR). At a 5 second rate*, round-trip efficiency is greater than 70%. At a 10 second rate, RTE is greater than 80%. This results in not only a more efficient use of your energy, but less heating, and therefore potentially less overhead for cooling your energy storage.

*discharging to V2 voltage in 5 seconds, and recharging at the same rate until the ultracapacitor is fully charged

BOOSTCAP ultracapacitors are designed with a very low equivalent series resistance (ESR), allowing them to deliver and absorb very high current. The low ESR of PowerCache ultracapacitors allows them to be charged very quickly, making them well suited for regenerative braking applications and other quick-charge scenarios. The inherent characteristics of the ultracapacitor allow it to be charged and discharged at the same rates, something no battery can tolerate.

If you wish to charge your energy storage device quickly (in applications like regenerative braking and quick-charge toys), you can charge the ultracapacitor as quickly as the system will allow, within reasonable limits based only on simple resistive heating. In battery-based systems, you can only charge as fast as the battery will accept the charge. This limits the system to only low to moderate charging rates, and may also limit how frequently one can charge, a significant issue in braking systems. Furthermore, the battery does not self-limit this charging rate,

9244 Balboa Avenue, San Diego, CA 92123 CH1728 Rossens

United States Switzerland

Phone: +1-858-503-3300 Phone: +41 (0) 26 411 85 00

Fax: +1-858-503-3301 Fax: +41 (0) 26 411 85 05

© Maxwell Technologies, Inc. | www.maxwell.com | info@maxwell.com