EV + Gas Generator = Hybrid?

[alohaspirit]

When my crx engine dies I might EV it
(now where have we heard that one before)


But my friend brought up an interesting point
which I dont exactly have all the answers for.


Can you put a small generator in the back and power it off that?

Will it work when its running or does the current need to be off for it to run?

It would be mostly used as a fallback. Going too far and draining the battery.
No need to tow back


Its just nice for someone to be asking questions. Means theyre interested.

[bwilson4web]

What sort of catalytic converter does the generator have? What are the emissions?

You realize 1 hp ~= 745 watts so that generator is about 3 hp.

What is the fuel burn per unit of electric power at 3 hp? Many generator fuel burn rates are at 50% power, not full power.

Understand I'm sympathetic with the goal but the engine-generator needs to be well designed. It might be simpler to get an older Prius, one that needs work, and rebuild it while keeping the Civic as backup.

Bob Wilson

[RobertSmalls]

The above generator may be able to recharge an EV at least partway, in a few hours. Therefore, leaving one in the car as a contingency might not be a bad idea. However, using a generator as a range extender is somewhat silly.

When you plug your charger into a gas generator, what you have is energy being made in the generator's gas engine, then a portion of that energy is lost in: the generator's electrical circuits, the charger, the batteries, the electric motor. Also, you'd need an enormous generator to do that in real-time. For a long trip, the only real option in my mind is to directly connect a small gas engine to a wheel.

[NeilBlanchard]

Hi,

This would be called a serial hybrid, which a very efficient way to go.

[alohaspirit]

Hmmm... ill explain

using it as a "range extender" is rather silly

but its mostly for contigency, or a "what if"

such as "what if" im 20 miles from my house but my battery only has 10 miles left
will this allow me to limp home?
or will i have to wait X hours at starbucks while the generator charges my car


of course, the ev will run purely on well, E
being plugged in whenever possible

[jamesqf]

Originally Posted by RobertSmalls

However, using a generator as a range extender is somewhat silly.

Why? It seems perfectly sensible to me (and to all those engineers working on things like the Chevy Volt :-)). Say I have an EV with a 40 mile range, and I want to make a 50 mile trip. So I crank up the generator, and effectively drive 40 miles on electric, 10 miles on gas (even though the generator is running all the time). Seems like that's better than driving a gas vehicle the full 50 miles.

Of course there are losses in the generator, but what you overlook is that an automobile engine is usually running at much less than its peak efficiency. Hook it up to a generator, though, and you can run it at best efficiency all the time, which ought to do a lot to compensate for the generation losses.

[Thunder]

That helps I just wanted to make sure I would not hurt the batteries doing this. The reason I am asking is we all know that lead acid batteries for now are the cheapest to use for EV converted cars. But from work to home its 20 miles 1 way with ½ being 55mph and the other being 35-45. And I go to the beach a lot which is 42 miles 1 way and no where to charge up but I am always there for at least 4 hours or more. So you can see why the extra miles are needed.

[Christ]

There is an E-Mini concept (not built my Mini or BMW) that has hub motors and makes 0-60 faster than most sports cars, with like 660HP (that number might be off, but it's a somewhat ridiculous HP figure for an EV) I don't remember the range, but it's got a small generator and gas engine where the spare tire should be, and it gets 80+ MPG while the generator is running. You ain't doing that with a fixer-upper Prius.

PML Flightlink Electric Mini Cooper - Car News/Green Machines/Car Shopping/Hot Lists/Reviews/Car and Driver - Car And Driver

It was also on TreeHugger

[NeilBlanchard]

Hi Christopher,

Yes, that Mini hybrid is a prototype that had 160HP electric hub motors in each wheel, for a total of 640HP, and IIRC, the generator was spun by a 2-cylinder 250cc ICE. And yes, they claimed ~85mpg while running in the hybrid mode, which is very impressive indeed.

The Aptera 2h will also be a serial hybrid, and again IIRC the ICE will be ~15HP -- big enough to "keep up" with the battery discharge in any situation. And it is projected to get ~130mpg, which is even more impressive.

GM really missed the boat using an existing 1.4L 4 cylinder ICE in the VOLT -- it is way too big, and adds way too much weight to the car. I think they are mentioning mileage in the 50mpg range -- woo woo.

[alohaspirit]

So is it safe to conclude


Q: Can you put a small generator in the back and power it off that?

A: YES


Q: Will it work when its running or does the current need to be off for it to run?

A: Yes to both!