An Austin-based startup called EEStor promised "technologies for replacement of electrochemical batteries," meaning a motorist could plug in a car for five minutes and drive 500 miles roundtrip between Dallas and Houston without gasoline.

http://ap.google.com/article/ALeqM5i...HZ0ryEBSrvGgWQ

Does using capacitors to power vehicles have a promising future or is it just another perpetual motion machine?

 

Everything i've read about it before has always been an "in theory if...." type thing.

 

Ultracapacitors are very, very good at absorbing or dumping a huge amount of power, but they are poor at storing energy - the energy density is maybe a tenth of what lithium-ion provides, and the discharge voltage curve makes much of that difficult to access.

They'll have a place in electric and fuel cell applications (in fact, Toyota's hybrids already use a sizable ultracapacitor in the inverter module), but I really have difficulty seeing the day where they are an outright replacement for chemical storage batteries.