Starting the Chevy ReVolt Hybrid project

by Ben N on November 30, 2010

Propane Generator for use in Electric Car NP-40 generator

Well, I guess I just threw my hat over the fence.

For some time, I have been wanting to do some work on my “Electro-Metro” Electric Geo Metro conversion to add a “range-extender” feature to it.

The idea is simple – provide SOME of the energy to power the car with an on-board generator. The car will still be electric, and still run on batteries, but will be able to go father per trip. In my case, I find that I do a lot of short trips (which I use the Electro-Metro for), but I also do some fairly long trips. For those longer trips, I use my Chevy S10 pickup truck. While I can get up to 30 mpg in that truck, there are still plenty of times where I am just transporting myself (not heavy/bulky items, tools, or materials) All I really need is just a very small, efficient car.

Rather than try to fill my Metro to the brim with batteries, what about using a generator to extend its range? By using a smaller generator, costs can be kept down, and the generator will run mostly near max throttle, which should keep its efficiency fairly high.

In ways that it will be DIFFERENT from the Chevy Volt, I simply picked two common complaints that I have heard about the Volt on web forums.

1) You have to haul around the engine, fuel tank, exhaust system, etc ALL the time, even if you never use it! (What a waste of space and weight!)

2) The Volt uses GASOLINE. Anyone who has ever left gas in a weed-wacker over winter knows that old gasoline sitting around is a bad idea. (GM solves this problem by automatically running the engine at a certain point if you never do.)

So, my solution to these problems is a) make it removable, b) run it on something other than gas.

A friend of mine donated to me an RV generator. It’s a variable speed, computer-controlled 3400 watt generator. And it runs on propane. Being from an RV, it’s ALREADY DESIGNED for use in a vehicle. It even features a remote start, allowing the user to electric start the generator from somewhere other than directly at it. This means I could control the starting the generator with something as simple as a button on my dashboard, or possibly even rigging it up to the original ignition crank position of the car!

Ever see those “cargo trays” that slide into the hitch receiver on a truck? It’s a great way to add a little more cargo room to a vehicle. Hey, what if somebody put a generator on there? Ooh! and it’s removable!? Imagine that. A way to extend the range of an electric car, that you don’t have to lug around on all your short trips!

I have often found that the best way to get something done is just to tell everyone you are going to do something. Now you HAVE to do it! That’s what I did to build my electric car. I just told everyone I was building one. I had no idea how I was going to do it. However, just telling people was the start.


Here’s a video to get your creative juices going.

Got any suggestions for this project? Leave a comment and let me know!


EDIT: After completing this project, I made a write-up on how I did it. That can be seen at:

More videos about the project at:

{ 2 comments… read them below or add one }

1 Daniel NETHERCUTT March 1, 2019 at 3:20 am

I am interested to see how this project turned out. I can’t find any more videos on it. I am wondering how long an ev would run strictly off of a generator like yours. I know that trains are electric and run very efficiently on diesel generators. One gentleman ran his 800w RV a/c unit on one for 12 hour before running out of a 20lbs bottle of propane. That’s about 4.5 gallons. The Tesla uses approx 300 watts/mile at 55mph. If it were powered by a generator it should go 800 miles on one tank by my figures. Or did I miss something?

2 admin March 1, 2019 at 5:02 pm

Hi Daniel,
Yes, I converted the electric car to a plug-in hybrid and ran it like that for a summer. It was a great project, although the generator certainly made a lot of noise and vibration. The joy of an EV is NOT having that noise!
I got the generator for free (because it didn’t work) and fixed it up. Unfortunately, it never ran at full power, so I didn’t have “unlimited range” with the car. It extended the range by about 50%, but didn’t have enough power to keep up with the average energy use.

The concept is similar to how a diesel locomotive works, although trains have special 2-stroke diesel engines that are specifically designed for running at peak efficiency. Unfortunately, generators are nowhere near as efficient as modern electric batteries and motors, so it’s still better to either have the gas engine power the wheels directly, or simply use just a large battery and motor.

Here’s a playlist of videos about the plug-in Hybrid Geo Metro:

Here’s a write-up on Instructables on how I built the project.

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