MIT researchers extend computer life without batteries

Researchers replace batteries with ultracapacitors to make long-running PCs

Researchers at the Massachusetts Institute of Technology have found a way to extend the power life of mobile computers.

Instead of using batteries, they draw power from an electronic device called an ultracapacitor. The approach is still several years away from being used as the main electricity source for commercial laptops and handhelds, but is already used for backup power in many small consumer products.

"A number of electronic devices already use commercial ultracapacitors for specialized functions," said Joel Schindall, a professor in MIT's Department of Electrical Engineering and Computer Science, in Cambridge, Massachusetts.

"For example, a clock radio may use an ultracapacitor as a keep-alive source in case of power failure, and even the old Palm III used an ultracapacitor to retain its memory while the AA batteries were changed."

The new technology could shake up the retail computer business, where computer makers already compete for market share by boasting of more power-efficient machines.

Chip makers battle for business by launching more efficient processors like Intel's Centrino and Advanced Micro Devices' Turion, trading high performance speed for mobile endurance.

Hewlett-Packard Co. also says its customers demand longer run-times. The company announced Monday that its HP Compaq nx9400 notebook will run on three levels of battery packs. Those range from the standard, four-hour unit to a substitute battery that adds five more hours, and a clip-on, supplementary battery that adds another 10 hours.

The speed at which a battery charges is also important to users. HP says its enhanced, lithium ion battery can gain 90 percent of a full charge after just 90 minutes of being plugged into a wall outlet.

By comparison, a consumer with a cell phone powered by MIT's ultracapacitor could gain a complete recharge in just a few seconds, Schindall says.

The new device is called a nanotube-enhanced ultracapacitor, or NEU. It works by applying nanotechnology to an existing electrical device; the capacitor.

Generic capacitors store energy as an electrical field. That is more efficient than standard batteries, which get their energy from chemical reactions. Even more efficient is the ultracapacitor, a capacitor-based storage cell that provides quick bursts of instant energy. The drawback is size -- ultracapacitors need to be much larger than batteries to hold the same charge.

The MIT researchers solved this problem by taking advantage of the enormous surface area of nanotubes; molecular-scale straws of carbon atoms that enable ultracapacitors to store electrical fields at the atomic level. Storage capacity (and charging speed) in an ultracapacitor is proportional to the surface area of the electrodes, so the nanotubes provide a great leap forward.

Despite this promise, researchers say they still have three to five years more work before they can replace a computer's main battery.

One drawback is that the ultracapacitor provides direct current power. That is suitable for running power-off functions like a laptop's clock, but most desktop devices use alternating current for their main operations.

High cost could also be a problem at first, because of low quantity production and meager capital investment in manufacturing facilities, he said.

On the other hand, the device could clear these hurdles by finding customers across a variety of businesses. From cell phones to automobiles, the ultracapacitor could supplement fuel cell power sources by acting as an emergency reserve for peak power use.

"The eventual implications are profound," says Schindall.

Join the newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.
Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Ben Ames

IDG News Service
Show Comments

Cool Tech

Bang and Olufsen Beosound Stage - Dolby Atmos Soundbar

Learn more >

Toys for Boys

Nakamichi Delta 100 3-Way Hi Fi Speaker System

Learn more >

Sony WF-1000XM3 Wireless Noise Cancelling Headphones

Learn more >

ASUS ROG, ACRONYM partner for Special Edition Zephyrus G14

Learn more >

Family Friendly

Mario Kart Live: Home Circuit for Nintendo Switch

Learn more >

Philips Sonicare Diamond Clean 9000 Toothbrush

Learn more >

Stocking Stuffer

Teac 7 inch Swivel Screen Portable DVD Player

Learn more >

SunnyBunny Snowflakes 20 LED Solar Powered Fairy String

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Tom Pope

Dynabook Portégé X30L-G

Ultimately this laptop has achieved everything I would hope for in a laptop for work, while fitting that into a form factor and weight that is remarkable.

Tom Sellers

MSI P65

This smart laptop was enjoyable to use and great to work on – creating content was super simple.

Lolita Wang

MSI GT76

It really doesn’t get more “gaming laptop” than this.

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?