Maybe large capacitors for hybrid vehicles also?

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Just a thought. Would it be a good idea to insert high capacity capacitors in between the batteries and the electric motor on hybrid vehicles? My idea here is to lessen the initial load on the batteries on launch maybe making them run cooler and longer?

Something like this maybe:

http://www.sonicelectronix.com/item_133 ... CAP30.html

i already think it is normal in purely electric vehicles, as part of the engine controller.
i know motor controllers for smaller engines include a decent size cap to increase respone times.

They do on vehicles with a hydrogen fuel cell as a power source-they are called ultracaps and they are used to eliminate the lag between instantly wanting to accelerate-they store a charge which is immediately available to the motor for no lag when trying to get up to speed.

Oooh. okay.

Interesting topic!

I love capacitors, they are probably my favorite electronic component next to transistors.

I did some quick research and was surprised to find very little about this on the Web. What I did find was that there is already a 'hybrid battery' being used in prototype electric vehicles. It is a combination battery/supercapacitor designed to reduce battery heating and extend battery life. I had assumed I would find info on basic 'motor-run' capacitors being used already as you stated, but didn't see much.

Drawing on what I already knew about capacitors, I can tell you that even ultracapacitors will never be able to replace batteries or fuel cells for long term energy storage/production, but that is not to say we won't be able to use them in vehicles. Capacitors charge fast and discharge fast, and as they discharge, the voltage across them drops. Even very large ultracaps will never match the overall available energy stored in todays modern batteries.

The most interesting thing I read that might be the best answer to your question concerned using capacitors for regenerative braking. I could definitely see this, a large capacitor could soak up the energy from a regenerative brake system and apply it back to the road while the battery does the work during cruising.

Another thought I had would be safety concerns. If involved in a collision, a shorted capacitor could be a dangerous thing, but, would only be lethal if a human shorted it and not a part of the vehicle's sheet metal. I suppose it could be a fire hazard in a hybrid vehicle too, as an ignition source for spilled gasoline, but we already have that risk in normal vehicles...

Cool question cw10

I've seen the effects of a LARGE set of capacitors if discharges accidently like a bolt of lightining and just as loud

the bank was used in a test cell that had an input of 460v/3ph an engineer was using a wire to keep his leads out of the way but was careless when removing his instrumentation leads and the wire used swung near the bank of capacitors.

It vaporized the wire instantly sending out a spray of molten copper that left a line across his clothes os flame. at least he had his glass' on ! ! they were ruined as well.

Has anyone ever heard of a slow discharge capacitor? I haven't.

Capacitors make terrible storage batteries. They cannot be drawn down in small increments.

ruveyn

^^^
but the powers that be are working on just that. at least that is what pop sci has been writing now and then for the past decade or so.

^^^
I'm still waiting for my flying car,

^ Wow, that's an awesome story.

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Most of you in this thread probably know this, but one revelation to me was that you can conceptualize that (high current) difference between a cap and a battery in terms internal impedance. With a cap there's virtually no resistance to limit the current flow (or generate heat to destroy a battery).

I guess the situation with caps and batteries in vehicles is sort of like with RAM and L2 cache; both have a role to play.

talk to paul moller and co. after your ship comes in. or befriend paul allen. in a more perfect world...

I suppose if a "temperature compensating thermistor" were used in the construction of a ultracap it would slow down the flow of electrons sufficiently enough. It's funny you mention that Ruveyn, I remember my folks got involved with Bulb Miser a number of years ago, and it's affect on a lightbulb was interesting. You'd hit the switch and instead of an instant-on, the bulb would light up fairly slowly.

Apparently it was developed by NASA and used to buffer electrical surges. Here's a link describing it: http://www.understandwebsites.com/bulb- ... tives.html

There could be a conductive layer of this stuff (separated by terminal of course) right before the terminals on a capacitor to keep it from discharging too rapidly.

i read that nissan was working on using ultracaps for its electric cars, maybe they are using something like the bulb miser technology on it.

I was at the very beginning of a team at the University of Akron called Challenge X. At the time, I had to sign a non disclosure agreement with GM and all that fun stuff, but now that it's over, I can blab all I want. The purpose was to design a hybrid vehicle that produced the least amount of pollution. Well, anyone who goes to Akron knows that Dr Hartley loves Batteries and Capacitors, so we set out to design a car that ran off of mostly capacitor power, if I am remembering correctly (I was only part of it for a semester, and it was at the beginning) Here is a pic of one of the bundles going in the vehicle. You can dissect the link to go to he main site and look at the challenge X page: http://challengex.uakron.edu/photos/bin ... &bg=c4d1db (Just delete to the .edu part) Good idea, but from what I heard, there were more problems than they anticipated. They did get it running and had fun driving it around the city though. It is actually funny if you know Dr Hartley seeing him and ANYONE in this car driving in downtown Akron in this thing. It must have been a site to see. I like him. He loves to blow stuff up... and make pickles glow. Seriously.

^^^
glowing pickles, eh? when day breaks and you don't need the light anymore, just eat 'em.