Electric vehicles. Small diesel generator to charge??

[MARK_VANDERBENT]

Ok , this may seem crazy, but I have seen diesel generators run for very long periods on small amount of fuel.
Why not have a small diesel generator to run an inverter to charge batterys at any time they fall below a certain charge?
Mostly when running .
Only thing you need to do is fill a small diesel tank on your vehicle once a month for small amount.
Just a fun thought !

[ktmrfs]

most hybrids us a gas engine miller or atkins cycle engine rather than the typical otto cycle. The advantage is much higher thermal efficiency, nearing that of a diesel. The disadvantage is that miller or atkins cycle engines have very poor low rpm torque. But couple that with an electric motor that has very high low end torque and you end up with a great combination. High thermal efficiency and very good low rpm performance.

I suspect that the gains from going to a diesel are mitigated by the cost and higher weight.

For maximum thermal effiency you want the exhaust temperature to be at ambient and cylinder pressure at the bottom of the power stroke to be at atmospheric pressure. The atkins and miller cycle reduce both compared to a typical otto cycle engine.

[Grit_dog]

To clarify for those that think the Jenny would be powering motors directly, He was not talking about a generator to run the car’s motor(s). Only charging the battery bank.
Either way, it’s a novel idea. But using Tesla’s level 2 charging as an example. Level one won’t do anything if you’re burning up battery on a road trip (since this concept is not needed for local driving).
Level 2 is about 80amps worth of charging which puts you in the 10kw generator range.
That’s either a he!! of aload in the trunk or a small tow behind.
Bottom line, if you want to make enough power to substantially supplement the batteries you need a big generator.
If it was that simple, they’d all come with a Honda 2000strapped to the deck lid, but it’s not.

[camperdave]

It's more like 20hp to sustain freeway speeds which is like 15kW. Not unreasonable, but still a lot of charging power. Typical 220v EV charging stations charge at 6.6Kw, but DC fast chargers are 50kw. Up to over 100Kw for Tesla superschargers.

It could be done, but you'd need a decent sized genset.

For the record, the only true series hybrid car I know of was the Fisker Karma. It had a 2 liter turbocharged Ecotec that put out 260hp running a generator. Driveline was electric only.

[winniman]

colliehauler wrote:
It would probably work to extend the range. You don't need a 150 hp generator, most cars when up to speed take very little hp to maintain that speed. Stop and go driving would be different. The smallest Diesel generator I have seen is 6k watts.

Kind of defeats the purpose of a electric car eliminating emissions with a generator running.

6kw is about 8 horsepower. Even if you say the car only needs 50 hp to operate it, that is still 37kw of power. A 6kw generator would take quite a few hours to recharge an electric car.

[Hank85713]

Just read that Mazda is going to unveil an electric car with possibly a small ROTARY engine to run a generator, but not the car. Engine is to be small and LIGHT as it will feature almost all aluminum construction. This is to happen at tokyo motor show soon.

[naturist]

BMW i3 with range extender, except it's not diesel. Chevy Bolt, too, I think, except it isn't diesel either.

[8_1_Van]

MARK VANDERBENT wrote:
Ok , this may seem crazy, but I have seen diesel generators run for very long periods on small amount of fuel.
Why not have a small diesel generator to run an inverter to charge batterys at any time they fall below a certain charge?
Mostly when running .
Only thing you need to do is fill a small diesel tank on your vehicle once a month for small amount.
Just a fun thought !

Seem crazy ? Yes , get a car like the Chevy Volt if you are a Chevy fan that GM has a hard time selling. Tesla is years ahead of any car company on the planet and have the longest range with the 2020 Tesla Roadster having a 620 mile range.

[Groover]

I car that gets 30mpg on the highway only has an average requirement of about 50hp. If you had a large enough battery pack to smooth out the demand peaks and valleys there would be some benefit to having an engine running constant speed to provide that amount of power regardless of the fuel or even engine type. If the re-gen system could take advantage of a GPS system to anticipate impacts of upcoming terrain there would be even more benefits.

I believe that the Honda Clarity comes the closest to being that type of vehicle of any on the road right now. I was considering one but with only an 8 gallon fuel tank and a fairly small battery pack it just seemed to me that it would require too many stops. Plus the cost to benefit ratio just didn't seem to be there.

[colliehauler]

It would probably work to extend the range. You don't need a 150 hp generator, most cars when up to speed take very little hp to maintain that speed. Stop and go driving would be different. The smallest Diesel generator I have seen is 6k watts.

Kind of defeats the purpose of a electric car eliminating emissions with a generator running.

[winniman]

If you need say a 150 hp gas engine to move a car, you would need a 150 hp generator to produce enough electricity to power the car. There are no freebies. I guess you could park the car for two days while a tiny generator charges the batteries back up.

[thomas201]

Weight. The diesel weighs more, the enemy of electric or hybrid cars.

[HadEnough]

Unless you are talking about charging the batteries only when you have the vehicle parked, you need a generator the size of the normal engine, Plus a few percent larger in order to account for losses.

[camperdave]

That would be a series hybid, like a locomotive.

No reason you couldn't do it. Pretty sure any factory EV would not let you start the car while plugged in so you'd have to do some electronics trickery.

[philh]

hybrids bring the best of both worlds. But, they cost more than ICE, and pure electric costs more than Hybrid. Customers in general have been unwilling to pay for the technology change.