Picture of DIY Plug-In Hybrid Car
This Instructable shows how I built a Plug-In Hybrid Vehicle.

A plug-in hybrid is a car which can run off a combination of electricity (stored in batteries) charged from a wall outlet, and some other fuel, such as gasoline.

This vehicle uses ONLY the battery-electric system to start with, and has manual control over when the other energy source is used, in this case, a propane generator.

Using only electric power, and THEN switching to a hydrocarbon fuel only when needed, is sometimes also called a Range-Extended Electric Vehicle, or EREV.

Think of this car as a poor-man's Chevy Volt or Plug-In Prius.

I already converted this Geo Metro to run on electricity. You can read all the details about that at my ELECTRIC CAR CONVERSION INSTRUCTABLE.

This Instructable will detail adding a second power source to the vehicle to extend its range.

I've been driving this car for about two years now as electric. The only thing I don't like about it is that I find that there are a few too many times where my destination is just a little outside my range, or there is no access to electricity at the destination to be able to recharge while I was there.

Adding the second power system to the car allows me to make trips that I would otherwise need to use a gasoline vehicle for.

In a nutshell - the generator makes AC electricity that powers the traction pack battery charger. The charger passes DC electricity into the batteries. By constantly "topping-off" the batteries, they are kept more full and allow the car to drive farther. The generator is NOT powerful enough to drive the car directly from. However, the generator can continue to run while the car isn't using any battery power, such as rolling downhill, or at a stop light.

So, the smaller, but steady power of the generator provides additional range, while the torque and energy of the electric motor and battery pack give the car good power for acceleration and hill climbing that the small generator engine would NOT be able to provide.

Also, engines running at a steady speed at fairly wide open throttle are MUCH more efficient than one running lightly loaded or at varying speeds (such as in a standard gasoline car.)

See more of my clean transportation projects at
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urwatuis8 days ago

This is a cool idea. Are you still driving this car? Did you address the propane tank safety issues? I would think all you have to do to make the passenger compartment safe is A) remove the hatch. B) weld a metal sheet vertically behind the rear seat. C) install a safety glass rear window

my clz prjct

Bobey1 year ago
This is crazy but my favorite car is a Geo Metro I know crazy right
rdelaplaza2 years ago
The whole thing is excellent... BUT talking about efficiency;
you are losing energy in the conversion from 120 VAC through the battery charger. That means part of the energy of the propane you are burning
is becoming heat besides the heat loss of the engine itself.
Which by the way could be used to heat the car in winter.
Generating 120 VAC power with the generator then
using a battery charger to convert it to 12 VDC is not efficient.
You should get a generator which generates 100% of its power at 12 VDC
(there are a few with that will generate 12 volts; problem is that only as a small percentage of the total generated power.. not good)
Then use those 12 VDC to charge the batteries directly, other solution could be using a 120 VAC 3 phase motor (very efficient; with an IGBT controller that will generate 3 phase current to control your motor) and feed the system with 10 x twelve volt batteries in series, that way you will only need a bridge rectifier (converts AC to DC) directly from the 120 VAC generator output to the batteries.
A suitable "regulator" should be used to avoid overcharging the battery pack, there are 100's of circuits out there, to build your own battery charge regulator. That will do the job in the most efficient way.
I'm an Electronics engineer and I'll help you if you want or need any help.
Electronics engineers- anyone Help. I have the Range issue on my Zappino electric scooter so i bought a 900 watt generator and hooked it up to a schumacher 72 volt charger (10 amp). But the motor is pulling 1500 watts at governed mode. (3000 watts max). So even going 10 miles an hour i couldnt charge fast enough.. It seems just like mentioned here that i should be able to turn the ac to dc and have more amperage. A bridge rectifier, Im not afraid i will build whatever or cant i modify the charger for more amps output. Speaking of output any input please will be much appreciated. Hell i will reward any savior(s)with some Grgich Hills Wine...Thanks -Treeology
bennelson (author)  rdelaplaza2 years ago
A few good points in there, but to be clear...

I got the generator for free. I did the whole hybridization with existing components I already had.

Also, I would NOT want a generator that puts out 12V, I would want one that outputs a bit higher than the voltage of the battery pack, which can be anywhere from 72 to 144V depending on how many batteries I have in the car.

While creating AC to go to the charger to create DC is NOT the most efficient way to go, I already had both the generator and charger. As for a suitable "regulator" to prevent overcharging, that's built right into the charger as well.

I had considered using a bridge rectifier to convert the output of the AC directly to DC, and running the car at that system voltage, but by that time I had decided that I wasn't really that interested in continuing to run the car as a hybrid, due to noise and space considerations.

Were I going to build a new hybrid from scratch, I would definately consider using an AC motor, IGBT control, etc, etc, but sometimes you can to weigh efficiency VS cost as well.

PS: Actually, I AM considering building a dedicated hybrid right now, but it will be a parallel hybrid rather than a serial hybrid. Still, the electronics and controls will be the most challenging part of the project.
trav9973 years ago
If i did this conversion with a truck and put batteries and propane in cargo area would this be legal?
Yes. people have been turning ford rangers into electric vehicles for years.
tootall11212 years ago
to love4pds. Your idea is self defeating, the power it takes to propel the car is one thing, adding the required energy to propel fans is another, and self defeating. You can't take in more power than the fans would take away. That's one reason electric cars need to be as aerodynamic as possible, to create less drag, and hence take less power to propel. I think teaming an electric motor with a CVT transmission is the way to really go, it would certainly help on take offs, CVT stands for constantly variable transmission, or gears to put it simply. Thus a motor spinning at a given speed would be able to propel the car from a standing start to high speeds without the motor ever changing speeds. What would change is the amount of power required to maintain that speed, but the slicker it is, the better. It doesn't take all that much power to propel a car at a steady fifty miles an hour, but to get there takes torque, and when you go faster than that, the power requirements to do it go up exponentially.
Why have a transmission at all? Put a motor at each wheel and you don't need a transmission.
tootall11213 years ago
Henry Ford's original idea was an electric car, but Edison recommended he not do that, with the technology available at that time. The model T's were made so that they could also run on alcohol, since at that time having a still was legal and there were a hell of a lot more of those around than gas stations. The Chevy Volt is doomed to failure. The batteries that would make it work well were bought out by Chevron, and hidden away, even though Toyota had already started building all electric cars with those batteries with good results and reasonable range. The Volt, however only gets 100 miles at best, 40 to fifty miles at worst, and has no self recharging method. Seems to me, a solar panel on the roof and or trunk could recharge the car while people are at work, the major use of many vehicles. However, if the range might only be fifty miles, and many people commute farther than that, it won't do the job... it's also gutless and has a hell of a time with hills, while depleting the batteries faster. Tesla is on the right track, but their methods are still too expensive to be viable. They actually use bunches of laptop batteries.

As to the safety issue, so what? Life is a gamble. So what if a bunch of people get killed in such vehicles? That helps the planet by reducing the population... you won't see me in one, I think there are better alternatives. You can fuel a vehicle with almost anything that will burn, with a few modifications and installing a "smoker" pot. I've seen a truck that runs on wood chips, dry grass clippings, anything burnable.
You're completely misinformed about the chevy volt. It has a 50 mile range which has been shown over and over again to be the average distance most people commute in a day. The generator recharges the batteries if you aren't the average commuter or if you are going farther. Considering the price of the vehicale and the enormous savings on gas, the Chevy volt is the best hybrid out there right now. The prius is awesome but only gets about 55 mpg. The volt gets closer to 98 eMpg.
bennelson (author)  tootall11213 years ago
The Volt is designed to run 40 miles on just batteries, and then switches to gasoline power after that. Between the batteries AND gasoline, the driver can go HUNDREDS of miles. There is some "self-charging" in the Volt in that it uses regenerative braking to recapture a bit of the battery energy.

I wouldn't say the Volt is gutless either, it has a sport mode, which gives fairly fun acceleration. I do not live in an area of mountains, but hills were not an issue at all.

I did a video test drive review of the Volt a while back. Please watch it if you have any other questions.

The SL version of the Nissan Leaf has a PV solar panel built in to the rear spoiler. It doesn't charge the traction battery pack, but DOES top off the accessory battery.

Full specs on the Volt and the Leaf are available on their web pages, for anyone who wants to know the actual range, horsepower, fuel economy, etc.

I AM a big fan of "gasifier" vehicles. I have several friends working on gasifier systems for home heating and power generation.
The guys over at Beaver Energy built a really nice wood-gas car:
I am not a car person, so this could be a very stupid question. But why not put a fan in the front to help generate electricity as a turbine would, or even use the one that is on the inside for the water thingy (please don't make fun, cant think of the name of it), while driving to recharge the batteries?
J-Ri love4pds3 years ago
Having a wind turbine on the front requires energy to turn. Even something small, like a radiator fan (is that the "water thingy" you mean?) in it's original location will use more energy to turn that you get out of it. I believe the best thing to do would be to completely seal off the grille area since very little cooling is required, or leave just enough to provide adequate cooling if heat is an issue.
love4pds J-Ri2 years ago
I meant as the car is driving using batteries the fan would spin from the wind of the moving of the car. So could that be the energy that moves the fan and charge the battery with that wind while using the battery or engine?
J-Ri love4pds2 years ago
That's what I thought you meant. It takes more energy to turn the fan than you get from a generator it would turn.
Unless you're driving into a strong wind, yep, that would be the case. The odd thing I don't see any of the electric car makers doing is adding a few solar cells for charging the batteries while it's parked. Granted enough solar cells to run the thing constantly wouldn't be weight efficient nor would they work at night, but most people drive to work, or wherever, then the car sits outside in the sun all day. Even if the solar cells only gave back half the charge used to get to work, it would be worth doing. I think in the eight to twelve hours most people work, a couple of cells in the roof, hood, or deck lid would be able to charge it to full capacity. Why aren't they doing this? Seems like a Duh to me.
bennelson (author)  tootall11212 years ago
Solar cells right now are not efficient enough for a few cells to do much in charging for an electric car.

A full-size, main-stream manufactured EV like the Leaf has a VERY large battery pack, and requires considerable power for recharging. The Leaf has something like a 20 hour recharge time from a 120V 15 amp outlet.

There are a few vehicles out there that do have a small solar panel, but it's for the ACCESSORY battery and or some summer cooling of the car. There are versions of both the Leaf and the Prius with small solar panels on them, but neither is for propulsion.

Don't get me wrong, I'm not saying it can't be done, it's just that it's not practical, due to the expense, size, and shape of the vehicle (PV panels are NOT aerodynamic!)

Vehicles that spend nearly all their time in the sun, use less energy, and are boxier, are good candidates for PV on the roof. There are a fair number of electric golf carts with PV roofs for example. I also know a guy with an electric pontoon boat. He has a fair number of PV panels on the roof of the boat (which shades the boaters from the sun.) He has lake access that is OFF his property, so there isn't any shore power available to him there. The boat is COMPLETELY solar powered, he doesn't even have a wall charger for it.

For most people, solar panels on their garage, with a grid-tie and net-metering payment system is what would make the most sense for a clean energy source. Alternatively, many electric power providers offer some sort of Renewable Energy Program, where you can purchase renewably sourced electricity over the grid.
Au contraire, recent advancements have improved them a whole lot. Still, any extra charge would be an improvement over nothing, since most parking lots are not equipped with charging stations.
They have improved a lot, but it would still be impractical to use them to charge the traction battery, unless by recent you mean in the last month or two. Look at all the protection that is required for the high voltage wires, not for functionality, but for safety. If you had PV panels that were connected to put out the voltage to be able to charge the traction battery directly, they would have tons of insulation around them, and the cars would closely resemble the VW Thing with a roof probably about 4" thick and quite top heavy. If you have the panels arranged to output a low voltage, you would lose huge amounts of energy stepping it up to a voltage that could charge the traction battery. The panel would also be nearly horizontal, which at many times of the year and at most times of the day results in very little direct sun exposure due to the high angle of the panel relative to the sun.
I see you're not up on the latest tech. There are solar panels that are much like cloth now. Not much thicker or heavier than a good denim. I'm not sure of their output, but ANY help would be good. It doesn't take the output you think to charge the batteries some of these vehicles use. In fact, it's better to add charge slowly. Maybe the tech hasn't reached these car makers yet, or maybe it's still too pricey. Everything is when it's the new thing. one thing I have always wondered about, is that solar panels traditionally use the light alone for conversion There has to be some way to put the heat energy to use as well. Oh, by the way, why not enough of a solar panel to keep the battery of a normal car charged? That wouldn't take all that much, but would be a boon to people like me that have vehicles that sit for long periods of time between uses.
Even driving into a strong wind, you would be ahead by blocking any unnecessary air flow (such as through the grille) in an aerodynamic fashion (such as having a contoured piece of fiberglass or aluminum covering the opening)

You would never get anywhere near half the energy it took to drive to wherever you are parked with PV panels, even if you were parked there from sunrise to sunset and a panel the size of the entire car were pointed directly at the sun all day. As installed in a vehicle, you might have an average of 25% of the panel's rated output due to the angle the panels to the sun. This, of course, assumes that the drive is further than a person in decent health could pedal a bike without breaking a sweat. If you drive 2 blocks, you might get half the energy back, but it's still a small amount.

It would also add a few thousand dollars to the initial cost of the car, and due to the depreciation on a car, would be money thrown away. I doubt that anyone would keep the car long enough for a PV system to pay for itself.

Since it would be foolish to RELY on car-mounted PV panels to get you home from work, one would be much better off setting up a grid tie system at home and charging the car there at night. There, you would be able to have the panels pointed directly at the sun, and sell the energy to the utility company during the day for more money that it costs you at night. Those panels will still be there making you money after the car is gone, and there's no way a van can park next to your house and block the sun.
love4pds J-Ri2 years ago
oh, got ya. i was thinking backwards.
The version I saw the test of was battery only. A prototype, perhaps. Still, the powers that be want it to burn at least some gas, or other fuel they can charge you directly for. What I'm saying is that with the batteries that Chevron bought up, it wouldn't be required to have the gas engine at all, if one was to make sure the car was charged and or charging stations were widely available. If that charge was created by solar or wind power, then there would be no pollution from it at all, no use of non renewable resources. The biggest drawback to battery power without the lightweight, high output batteries is that the vehicle gets heavy having to tote common batteries around. Also, the current electric motors are still rather heavy, weight as we all know is the enemy of mileage. The advance that will change everything either hasn't happened yet, or has been hidden. You used to hear a lot about room temp superconductor research, but the last few years, I've heard nothing about it. Did it get invented then tucked away somewhere? We'll never know. It's actually possible to have a super miniaturized reactor that would power a vehicle pretty much forever, but try getting that past the regulators. Cold Fusion would make that even more likely, and fairly safe. Don't hear much about Cold Fusion these days either, hmmm.
grimdaddy4 years ago
Your rig is very well designed and constructed. ...But You really need to think A LOT more about safety. Although propane tanks are relatively safe. The tank should either be better protected and/or centrally located in the vehicle. The best option would be an external mounting above the vehicle. The same goes for the combustion chamber as noted by other comments. Isolation is critical to passenger safety. To help you better understand my concern, please do a bit of research on the term BLEVE: Boiling Liquid Expanding Vapor Explosion. It is a nasty and very real possibility in the event of an accident. I have friends who are propane SFX guys and they have related some very scary stories concerning faulty equipment. Please be careful and seriously rethink a redesign for fuel tank protection.

OMG It Might be unsafe!!! People, living on the planet earth is inherently unsafe. Yes you try to make things as safe as possible but I am starting to get really tired of the alarmists squealing like a stuck pig on nearly EVERY instructible. The only way to be safe enough for these alarmists is to snuggle into a cocoon with purified water and intravenous feeding and never do ANY thing at all. Excuse me but life itself is a terminal occupation with risks around every corner. Minimize the risks as much as possible and don't do things that are blatantly stupid.

Many people are very correct that if these alarmist had gotten their way through the centuries we would NOT be living as we are today... Don't go outside the cave, you might get eaten! Don't stay inside the cave, it might collapse. Yeesh!!
I'm old enough to have used metal monkey bars over concrete in my local parks and never had soft stuff to land in when on the swings with rusted chains. I used metal cap guns with out bright orange plugs in the end too. Putting a Propane cylinder made for a BBQ and not made to be carried inside a vehicle is just stupid dangerous to others. I don't care if this guy kills him self, it's just the kid next door does not deserve his home destroyed because this guy wants to experiment in a housing neighborhood. You can tell from the look that it is even an old cylinder. He does not even have a safety bar above the cylinder. That would protect the valve from being sheared off in an accident. That's not alarmist, it's a reasonable cheap precaution.
Considering that I have recently seen playgrounds with just such equipment does not mean anything as to your age... you could be 5 or 25... Point is moot.

As for the rest... pray tell, how do you get that propane tank from the place of purchase to your house? Do you carry it home by hand? No? Perhaps you use a cart or dolly? No? Then golly gee whiz you just put it into your car... and probably far less securely than this guy did... did he put the tank out on the front or rear bumper? No? Gee, it is reasonably protected.... point is also moot.

What about that kid who decides to smash a lighter against the ground with a hammer... does anyone deserve to lose their house from the resultant fireball? Nice appeal of "for the kids"... Point is moot.

Your "reasonable precautions" are just that... if you are so awesomely clever about how it should be done with "reasonable precautions" then Please post your own instructable to show us how to do it "properly.... until then... Point. Is. Moot.
you are moot. this setup is not safe. Taranach, all your Points Are Moot.

there needs to be a division between the generator/propane tank and the passengers compartment. For example look at how RV's have used and mounted tanks and generators for many years.
Been a while since I last looked at this one, had to refresh the memory... Yours is the first that makes any sense as to the "safety" aspect... You are correct that in the pictures there is no separation between tank, generator and passenger compartment, you are also right that it should be addressed... However, did you also notice that he plans to box it in at the end of the instructable? There have been no updates so can't tell if he did.

As to what I said and what I was specifically referencing? Really? Seriously? that is the best you can come up with?

Your point is not "alarmist", yours is precautionary considering what you are working with. I have no problem with that. Suggestions that are proactive and helpful are all good. The others were "alarmist" and negative and indicating that it should not be done at all.. My opinions were valid for the issues raised and statements made. I still stand by them. Yes, sometimes refinements need to be made for various reasons, including safety, and suggestions to make something better are also good, but to not do anything at all because it might be "unsafe" is ridiculous. We wouldn't have 90% of what we have today if nobody ever did anything "unsafe".

Did you also know that when locomotives were first introduced, they were restricted in how fast they could go because "traveling above 30 miles and hour" was deemed unsafe and even hazardous.Guess we should all go back to horse and buggy. No more "unsafe" cars!
Don't forget the dangers of di-hydrogen monoxide (did I get that right?)
Heh heh heh!      ;)

Which part of the cave is the dangerous part again? Front (where the landslides hit one on the head with falling rocks if you venture outside), or the back where you can't dig out after a collapse?

BTW, I know a man who bought a car in the 1950's, converted it to propane and has been driving it ever since. He only wanted to buy one car in his lifetime and he's in his 80's now. The car has over 3 million miles on it and he just does basic maintenance, lube, oil, waxing, etc.
Kudos on an impressive project that I cannot even begin to comprehend. Electric cars aren't my thing, but I am glad there are guys like you out there thinking outside the box. One of you guys will be the next billionaire some day. I am only commenting because I saw all the negative stuff. Some people nit pick everything on here. The only safety thing I could see to anyone other than yourself would be to firemen. Maybe if you put a little hazmat placard on the back everyone would be happy.
ben2go4 years ago
This is a cool conversion.However, it's not legal in any state.With a sealed generator compartment to protect occupants from explosion and a DOT approved tank,it will be half way there.The flooded lead acid batteries put off a gas while charging that is both toxic and explosive.I'm not flaming or degrading your project.In fact I really like it and it would be fabulous in a small pick up.I'm just not sure that you have all the information needed to make this a safe conversion.
bennelson (author)  ben2go4 years ago
This car uses SEALED batteries, not flooded.

The main contactor, and other electrical connections are in a sealed box under the hood.
It's not the batteries that make it illegal, friend. Transporting a cylinder in an enclosed passenger cabin is against DOT regulations, as is operating a combustion engine in the passenger compartment.
I agree and any state some one lives in that has vehicle safety inspection as where I do will not pass the inspection with this "conversion".
Also propane is a heavy gas and any leak it will accumulate at the lowest point in the car and then BOOM...
As for your (bennelson) statement of no possibility of sparks you are wrong - THE GENERATOR. Also you have the generator sucking it's air from the passenger compartment as well. I would never ever drive or be in a car like this.. Now if it was in a pickup truck; I would put these items except the propane tank into a truck tool box. Then use a DOT tank mounted either in the bed or under the truck..
This would work except you will have to enclose it in a heavy sheet steel and insulated box with vents to outside and the propane tank mounted OUTSIDE of the car.. The tank will also have to be DOT certified - this certification means the tank will not rupture on impact in an accident if it is hit...
I and others are not putting down what you did; BUT how you did it; it is not a safe conversion..
I agree with what your saying, however this conversion looks to be more proof of concept rather than a final product. On that note if he ever got pulled over in that car they would arrest him and make him tow the car home.
rykonen jpayton3 years ago
I agree that this is great proof of concept. Now we just need someone to take menahunie's advice and make an Instructable with DOT certified transport so we can all see how to do it legally. Nice going bennelson!
yea this vehicle is badass but has some safety issues for sure. I guess for now... at least make sure the windows are open when the generators running hahahah and good luck!
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