DIY Volt Hybrid - Open ReVolt style

[cujet]

The 20 pound (really 15-17 pound) propane bottle will get quite cold running a 3500 watt genset. You may have problems sustaining rated power unless you run a larger tank.

I like your idea very much. A pilot I work with built a gem car with a Honda generator. He was able to extend his range enough to drive it to work. However, his 115V charger only ran on one leg of the 220V genset. So the generator/charger setup was not putting out anywhere near enough power to sustain the vehicle. Maybe 1500 watts total boost.

I wanted to work with him and build a simple charger and voltage regulator that would be much more effective. However, the generator was stolen right off the back of his car. My idea was simply to build a basic FWB and regulate the output according to need. The voltage of his battery pack was close enough to work, without massive difficulty or expensive equipment.

[bennelson]

Cujet, let me know more about your idea.

I am SUCH a NOVICE when it comes to exactly how battery chargers work.


I did order that "demand" regulator, and it just showed up in the mail today. I am hoping to hook it up tomorrow. Hope I have the right adapters to connect everything together!!!

[cujet]

In the case of the gem car, he was running a bigger battery setup, a more powerful motor and controller. The nominal voltage was 120, so simply taking each 120V leg and rectifying it to DC would give enough voltage (maybe 150 or so) to charge the batts without any form of "charger". Setup an electronic (or manual, rheostat adjustable) regulator that limited generator output to some "adjustable" level that worked (say, 135-140v downstream of the bridge) and it would be self regulating enough to work while driving.

Not much to a system like that. Just a full wave bridge and a commercially available generator voltage regulator.

Remember, the DIY regulator would limit voltage to the rotor (armature) of the 115-115-220 genset, in my example. So, both 115V legs would be at the same voltage if under the same load.

Your genset could be different and I am unfamiliar with it.

[cujet]

Put another way, the system I proposed functions just like an automotive alternator. It produces AC, rectifies it to DC, includes a regulator to control voltage at 13.8v and simply connects directly to the battery. The battery never overcharges and the battery level is maintained.

[bennelson]

I just got the genny to fire up!

I was working out of town for the last few days. Before I left, I ordered the on-demand regulator.

By the time I got back into town, it had arrived.
The demand regulator is interesting. It only allows fuel to flow is there is a vacuum on the output end. I could blow into the intake end of it, and no air would go through. If I sucked on the outtake end, the valve inside allows air to flow.

In this way, you can open up the valve on the propane tank, fuel will flow to the demand regulator and stop right there, UNLESS the generator is running.

This means I SHOULD be able to have everything mounted on the back of the car, open up the propane, drive a while, and THEN start the generator (assuming I can figure out that remote start.)

I should still add that 12V solenoid shut-off, but it's not needed for the moment.

Today, I went to the hardware store to get hose barb adapters to connect the regulator to the propane tank and the generator.

Once I had it all hooked up, I cranked the starter. It fired right up!
Now I did NOT have a load on the generator, and the exhaust was kinda smokey, but it DID START!

Next up, move it outside so I don't gag on the exhaust, and try out a load on it.

[bennelson]

Further Experimentation:

The 20-amp GFI outlet I got refuses to work with the generator. I didn't have any other spare outlets around, so I just directly connected the bare wires up to a Kill-a-watt.

With that, I was able to measure volts, amps, and hertz. The generator is a little erratic with no load - like a lawn mower when you aren't running the blades, you can hear the engine speed change up and down.

I load tested it, first with a 250 watt heat lamp. When that worked, I tested it next with an electric space heater. That heater has a low, medium, and high setting, which is actually 500, 800, and 1250 watts.

I fired up the generator, then turned the heater to low. The genny speed increased, but smoothed out as well. As I turned the setting on the heater up, the speed (and loudness) of the generator increased.

I ran the heater at 1200-1300 watts for about 5 minutes or so. The generator had no problem, although its exhaust started melting a hole through my plastic cart....

[bennelson]

Well, I have sort of been messing with this generator all day.

The good news is that I got all the hose barbs needed, the demand regulator, and the primary regulator working together.


THE DEMAND REGULATOR


200,000 BTU PRIMARY REGULATOR

I even took an inexpensive breaker box and got it set up with an electric outlet. (Although it was a 15 amp instead of the 20 amp GFI)



Once I had everything rigged up, I was able to fire up the generator and have it power an electric heater. The generator seemed to work well providing over 1200 watts to it.







Watching the Kill-a-watt, I could check the electrical specs on power from the generator. it sure isn't wall power. It does vary a bit in its frequency and voltage.

Also, the primary regulator gets COLD! Like -3 degrees farenheight cold. It doesn't help that it was 19 degrees outside today.

After I had played with the generator a bit, it got into a mood where I could start it, it would run for almost exactly 3 seconds, and then die. It was very regular, like it was an electronic issue. The generator would just cut out, not sure why.

I came back to the generator an hour or so later, and it seemed to work ok again. Weird.

The generator is pretty loud too. I need a muffler for it.

[Nerys]

if you run into a flow rate problem just use TWO tanks. double the flow double the range and half the load on each tank (the freezing tank issues that someone else said you might have might be causing it not to run till you come back later??? ie it warms up??)

maybe a small heating pad on the tank itself? (safe??)

[sawickm]

Originally Posted by bennelson

This means I SHOULD be able to have everything mounted on the back of the car, I went to the hardware store to get hose barb adapters to connect the regulator to the propane tank and the generator.

Ben,

You should look at a toroidal LPG tank for your finial installation. It mounts in the trunk were spare tire goes. This is an example: ICOM North America :: Tanks

They can be found anywhere propane/car conversions parts are sold.

-Mark

[bennelson]

That toroidal tank looks pretty cool. I had never even heard of those before!

I know that some of the dual-tank "Grease-Cars" used oil tanks that were designed to fit in the spare tire well. I always thought that was a nice use of space.




(EDIT)
ARGGGG!!!!
It's too darn cold outside!!! Well below freezing. I have no basement and an unheated garage. I can see daylight through the walls. NOT a good situation for working on a hybrid car!

I can't hook propane hoses up any more. The hose is too stiff in the cold to be able to get connected or disconnected!