Hacking the Hybrid Vehicle  

by John Gartner 
http://www.wired.com/news/autotech/0,2554,69519,00.html
November 16, 2005 

Engineers are developing adapter kits for hybrid vehicles that will 
increase their efficiency to 100 miles per gallon by powering them 
solely on electricity during short trips. 


Today's hybrid vehicles use electricity stored in batteries to assist 
the gasoline engine in acceleration and to completely power the 
vehicle while idling or at steady low speeds (generally less than 
25 mph). Vehicles such as the Toyota Prius, Honda Civic Hybrid 
and Ford Escape Hybrid include drive-train management systems 
that automatically decide when to use the batteries or 
internal-combustion engine. 

Enter CalCars and EDrive, organizations developing modification 
kits that enable the Toyota Prius to be recharged from the grid. 
And a new group of automotive component suppliers, the 
Advanced Hybrid Vehicle Development Consortium, hopes to 
develop technology that enables hybrids to run without help from 
the gasoline engine for up to 50 miles. 

Referring to "plug-in" hybrids, David West, vice president of 
marketing for consortium co-founder Raser Technologies, said 
that "80 percent of cars would be able to drive five days per week 
without using their combustion engines." West said consumers 
would save money since the equivalent of one gallon of gasoline 
costs just 60 cents in electric power. 

Consumers have rejected plug-in alternative vehicles in the past. 
But with gas prices hitting record highs, members of the 
consortium believe the timing is right to try again with new and 
improved technology. 

The consortium will develop a prototype hybrid vehicle within a 
year that includes more-powerful electric motors, longer-lasting 
batteries and ultracapacitors that can store electricity used for 
acceleration, West said. The prototype will cost about as much 
to build as today's hybrids, because some components such as 
the flywheel will be eliminated. Not only will the vehicle get more 
than 100 mpg, but consumers will save even more by tapping 
into the grid. 

The group hopes to license the hybrid technology to auto 
companies that have yet to produce hybrids, which would 
"enable other automakers to jump in the game without having to 
do 15 years of (research and development)," West said. 
Other companies participating in the group include lithium-ion 
battery manufacturers Electrovaya and Enax, utility Pacific Gas 
and Electric and Maxwell Technologies, a company that wants 
to introduce its ultracapacitor technology into hybrid vehicles. 

Richard Smith, Maxwell's executive vice president, said 
ultracapacitors -- which store energy by separating negative and 
positive charges along plates -- should eventually be included 
in all hybrids because they are 10 times more powerful than 
batteries at providing the bursts of energy needed to accelerate 
a vehicle. Ultracapacitors are 98 percent efficient when receiving 
energy from the regenerative braking systems used in hybrids, 
while batteries are 60 just percent efficient, according to Smith. 

But ultracapacitors aren't nearly as efficient at storing energy, 
so cars traveling more than a few miles will need batteries as well, 
Smith said. Ultracapacitors haven't been practical until recent 
improvements were made in the technology. 

Earlier this year, BMW introduced the X3 EfficientDynamics 
concept car, and students at Brigham Young University 
developed an electric drag racer, both powered by ultracapacitors. 

Perry Carter, an associate professor at BYU who worked with 
students on the vehicle, said ultracapacitor technology is 
promising but not yet practical -- the drag racer used $22,000 
worth of ultracapacitors for a 14-second run on a track. 

The original Toyota Prius concept car included ultracapacitors, 
according Dave Hermance, Toyota's executive engineer for 
advanced technology vehicles, but they didn't make it into 
the production vehicle because of their cost and size. 
But those were previous-generation technologies, and Smith 
said the price of new ultracapacitors is now on par with batteries. 

Hermance is still not convinced. In general, he said, 
ultracapacitors are better suited to large vehicles like trucks or 
buses that stop and start frequently, because their heavy loads 
generate a lot of energy when braking. 

Plug-in hybrids "are not viable with today's battery technology," 
Hermance said. He said the Prius' power-management system 
keeps the batteries charged at 60 percent, plus or minus 
15 percent to extend their life. Running solely on electricity 
would discharge the batteries beyond their optimal range and 
burn them out after approximately 2,500 cycles, or about 
six years of use, he said. 

Selling plug-in hybrids will also cause confusion with consumers 
and could hurt sales, Hermance said. Most people don't want 
the responsibility of recharging batteries every day. Plus, he said, 
manufacturers spent years convincing consumers that hybrids 
were not like the electric vehicles that failed to gain commercial 
acceptance. 

But Raser Technologies' West said powering a vehicle with 
electricity will cost about a quarter the price of using gasoline, 
which he believes offsets any inconvenience from having to 
charge the vehicle overnight.