Cooley On Cars
Car Tech 101: Capacitors arriving under the hoodBrian Cooley explains why capacitors could be better than a battery for new and coming car-tech tasks.
[MUSIC] Most electricity stored in your car today is either in its 12V battery that runs the starter, lights and ignition, or in a big, motive battery if your car is an EV or a plug-in hybrid. But there is another way in a capacitor. Capacitors, or 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 lead plates and acid solution. And fourth, they laugh at extreme weather. [MUSIC] But traditionally one big downside has kept capacitors out of a cars power train 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. [MUSIC] 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 they're 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. [MUSIC] Toyota's Supra HV-R hybrid race car used a Supra cap in its powertrain to store power for an electric boost motor. And in doing so, it won the Tokashi 24 hour race in 2007. A capacitor Which is like a battery, but charges in seconds. More down to earth, Mazda is oddly named, IE loop tech, in their cars today uses the 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 free wheels 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. [MUSIC] More car [UNKNOWN] demystified, right now at CNETOnCars.com. Click on cartech 101. [MUSIC]