Gadgetory

most electricity stored in your car today is either in its 12-volt battery that runs the starter lights and ignition or in a big motive battery if your car is an EB or a plug-in hybrid but there is another way in a capacitor capacitors are caps store electricity like batteries but differing in four major ways first they charge really fast second they discharge or deliver electricity really fast both of those behaviors because unlike your car's battery capacitors store electricity as electricity not as a chemical soup that contains electric potential thirdly caps are light no LED plates and acid solution and fourth they laugh at extreme weather but traditionally one big downside has kept capacitors out of a car's powertrain and that is low energy density capacitors have usually held a small fraction of the energy found in a car battery and took up a lot of space to do that enter ultra capacitors these have a much higher energy density so they can do more work and yet still fit inside today's tight engine bays and other locations and their time seems to have arrived on the coattails of new car tech like automatic start/stop electronic adaptive suspension and electric turbos each of those demand a lot of new current that is delivered in as little as milliseconds yet to preserve efficiency want their power source to be recharged easily capacitors have that written all over them Toyota's Supra hvr hybrid race car used a Supra cap in its powertrain to store power for an electric boost motor and doing so it won the tokachi 24-hour race in 2007 a capacitor which is like a battery but charges in seconds more down-to-earth Mazdas oddly named ie loop tech in their cars today uses a capacitor but not to drive the car in their case they use it to power accessories and that takes load off the traditional harder to charge lead acid battery ie loop uses a special alternator that freewheels when the engine moves the car but the moment you let off the gas it wakes up to turn outgoing energy into electricity capacitors themselves are nothing new but super capacitors being found under the hood likely will be more car tech demystified right now at CNET on cars.com click on car tech 101