Any car tech enthusiasts here?

[DaveKDEN]

Looking for info from someone who's got a tech background for a question regarding gas/electric hybrids.

Thanks,
Dave

[Wing_Z]

...?

[DaveKDEN]

Hey,
I was wondering about the feasibility of a small efficient internal combustion engine hooked up to a constant speed integrated drive generator providing electrical power for dual electric drive motors (front and rear) on a gas/electric hybrid car? I've been musing about whether such a system would benefit from any efficiency improvements over the system GM is using in the Chevy Volt. My understanding of the Volt is the ICE drives a generator that charges onboard batteries (which can also be charged via a plug-in as well). The batteries then provide power to the electric motors. I was wondering if a CS-IDG providing power directly to the electric drive motors would be more efficient, since it would bypass the battery charge/dis-charge cycle. By using a small ICE "tuned" to operate at it's maximum RPM efficiency, it's relative fuel efficiency should be fairly high. I'm thinking such a vehicle could bypass the need to have a large battery bank thereby lowering it's cost and complexity (at least until battery technology improves and costs come down). I threw this question out as my expertise in this area is very limited.

Cheers,
Dave

[Wing_Z]

Dave you do need to have storage of some sort, otherwise you'd have to size the IC engine for peak load, which defeats the purpose somewhat.
This can be a battery or a capacitor, or better still, a combination of both.

Hybrids fall into two main categories:
One is where the engine doesn't drive the wheels directly (series hybrid)
The Volt is in a sub-category, which allows plug-in charging of the batteries

The other is where the engine drives the wheels, assisted by the electric motor (Parallel hybrid)
The Prius is in here, and the newest one can plug in too, to charge the battery.

Don't know if this helps, I'm sure others might contribute better...

[safn1949]

I don't pretend to be an expert on this type of thing but you have to take into account the various inherent inefficiencies of any system.Some power is always wasted,thus the need for a storage system.The generating setup will always be at less then 100%.The generating engine would have to run almost constantly in my opinion to power such a setup and it would seem to be an inefficient way to do things.But until there is a major breakthrough in battery technology,I feel electric cars are a waste of money.

It has been stated that the break even point of a hybrid is around 9 years or so.I might be off on the actual number of years,my memory fails me.In other words you would have to drive that crackerbox that long to save enough gas to make it worth buying in the first place,The Volt is 15 years or so.

People also don't realize you have to plug that thing in somewhere,thus using energy.They act like it will come from some magical source that won't use any fuel.

Remember,the opinions expressed are worth what you paid for them....nada.:USA-flag:

[Piglet]

Any car with basically two engines is gonna cost more in maintenence, reliability, complexity. Just ask any twin aircraft owner! If you are trying to save the planet, just drive your present car till it falls apart, thus saving the materials, and energy to make a new one.
I've always felt that hybreds will prove to just be a blip in automotive history.

[DaveKDEN]

Any car with basically two engines is gonna cost more in maintenence, reliability, complexity. Just ask any twin aircraft owner! If you are trying to save the planet, just drive your present car till it falls apart, thus saving the materials, and energy to make a new one.
I've always felt that hybreds will prove to just be a blip in automotive history.

Hey Tim,
I've heard that electric drive motors are actually quite a bit less complex than ICE's. Also, a small "optimized" ICE acting as an electrcial generator would be mechanically less complex than modern ICE's. However, I'm not an expert.

I'm not looking to replace my cars, as I feel the payback on getting rid of a perfectly good car for a hybrid is too long to make it worthwhile. My thoughts were more of a musing on the possibility of such a drive system. Seemed somewhat logical to use a small ICE combined with a CS-IDG for a generator as the infrastructure is already in place (gas station on just about every corner). Was just thinking of a way to get more bang for your buck out of a gallon of gas while battery technology matures enough to make pure EV's practical and cost effective.

To me, the two biggest problems of EV's are limited range and long re-charge times. I like the concept of the Chevy Volt because you can travel practical distances and don't have to worry about your batteries dying on the road - just drop by a gas station and fill it up as your elecrtical generator is on-board. I was just thinking you could simplify things further by getting rid of the expensive battery bank and run the electric drive motors directly - thus saving cost, complexity, and weight.

Makes for an interesting discussion though.
Cheers,
Dave

[DaveKDEN]

One other thing - I'm not sure if all the proponents of pure EV's have thought enough about what happens to batteries during extended duration cold weather conditions like we can get in the Denver area (as well as many climates throughout the World). Lots of So. California types seem to be running the show with EV's. Last I checked, it rarely gets to freezing in So. CA.

Not really meant (too much) as a slam, but it's something that needs to be considered from a practical standpoint.

Dave

[Snuffy]

I can tell you from experience that batteries tend to blow up more frequently in excessive hot weather as well.

Since I've lived in FLA for almost 8 years now I have had to replace my battery in my truck 4 times ... battery life here is about two years due to the power consumption to run the A/C at excessive quantities.

[GT182]

When automakers can build an electric car like the Telsa, and have a lower price I might buy one.

Their Telsa gets 280 to 300 miles per charge and only cost about $6 dollars to recharge, as I was told by the owner and his wife who own one here in DE.

Link here.... http://www.teslamotors.com/

[thedude247]

This little rant of mine doesn't have anything to do with pure electric cars, but rather hybrid vehicles.

I'm a mechanic by trade, I won't pretend to know all there is to know about cars but I do know my engines quite well. To put it simply for you, the best possible efficency amd operation of your engine relies heavily on the 'Loading' that the engine has to endure.

What I mean be your engine 'Load' is that your vehicle engine is never just propelling your car, but other systems in the vehicle, be it you AC, Radio, the number of wheels driven. You will never notice the droop in you RPM's because all these systems are being run regardless if you using them or not.

Back to the Hybrid question, your engine will have an electric generator running of it, as mentioned already, this means that you engine will have to work a little harder to keep up with the extra 'Loading' on the engine.