DIY Open Source Plug-In Hybrid

[Daox]

I'll have to ask Tom. He has the literature for it but it doesn't seem to be real clear as to what the min/max input voltage is for it. I know we hooked it up at the makerspace and I'm assuming that that was 3 phase 240V input.

[MetroMPG]

I think I'd also start by making a list of other DIY plug-in hybrids.

See if you can improve somebody else's wheel, rather than re-inventing it completely!

[Daox]

Just looked up the specs on the controller. The literature says 200-240VAC which I'm told by an engineer at work needs to be multiplied by 1.35 to get the actual DC voltage that is used after the power is rectified. So, that brings us to 270V DC. Talking with the electrical engineer here he didn't seem to think that it would hurt the controller to try out lower voltages. It will simply set off an alarm on the controller.

I did send an email to the mfg. We'll see if I get a reply.


Edit: Corrected formula

[bennelson]

Originally Posted by MetroMPG

I think I'd also start by making a list of other DIY plug-in hybrids.

Anyone have some good links for other DIY Hybrids? Please post them here!

If I want to be able to "cruise" at 55mph+ and have the ability to do that at least some of the time on the motor, instead of the engine, I'll need to know how many horsepower are required to do that.

Can anyone help with some horsepower calculations? For now, let's assume that we want to use either a VW Rabbit Pickup, a Subaru Outback stationwagon, or Chevy S10 pickup truck. How many HP are needed to push those vehicles down the road at 55mph? Then we can find a motor - AC, DC, or brushless DC powerful enough to do that. We also need to figure in the RPM range of the motor for how it would be connected to the vehicle, and the gear ratio required. Does anyone have a link for a good HP calculator?

Once we figure on a motor, a matching controller can be found/bought/built to go with it.

[ProDarwin]

I'm late to the thread, maybe I'll have more time to contribute later but:

A) I am a mechanical engineer, I'd be happy to lend Design/Modeling/Drafting/FEA services.

B) Regard a vehicle for an AWD hybrid... choosing something that has a longitudinal mounted motor is a poor choice as you have the drive losses of the 90deg bevel gearset. This would eliminate Subarus, S10, etc. Something that is FWD based would be a better start as the FWD engine/trans could be left intact, while AWD rear components could be sourced/modified.

A Honda Civic can be converted to AWD through some fab and use of CRV rear components connected to the electric motor for example. Or just start with a CRV. Many FWD SUV Crossovers are like this (and this is exactly how the RX400h works - ICE front, EV rear).

Also when connecting to the rear diff , it would be worthwhile to machine a straight/helical gear to replace the bevel ring gear on the diff. This would again eliminate the 90deg turn in the driveline which is a significant loss contributor.

My gut feeling is the easy button is a FWD crossover, or a Civic/Integra with CRV parts out back. Getting further into home-fab, you could simply make a frame to mount a Miata crossmember under the back of almost any fwd car. Not sure how much $$ you want to spend on a donor vehicle.

Edit:

C) HP calcs are easy. Make sure you take into account grade-ability. I can help with this if necessary. I have spreadsheets for this, and also spreadsheets for simulating all of the drive-cycles, provided you have a BSFC chart for the ICE.

[Daox]

Just respoke with the electrical engineer here and he corrected himself. You have to multiply the AC voltage by ~1.35 to get DC voltage. So 270V looks to be the minimum per the literature.

[bennelson]

Originally Posted by MetroMPG

start by making a list of other DIY plug-in hybrids.

Great, lets start that list:

XR-3 - Plug-in Parallel Hybrid you can buy plans for.

Poorman's Propane Serial Hybrid.

Mike's 5th Wheel Honda Insight

The original Mother Earth News Hybrid

(Looks like some good info coming on this project, but not updated on their web page yet.

[MetroMPG]

http://ecomodder.com/forum/showthrea...ress-5599.html

http://ecomodder.com/forum/showthrea...pgs-19823.html (though he doesn't post details of his build on EM)

Jeffrey M. Reiss' 2004 BMW 530i EMIS

David Hrivnak's 2004 Chevrolet Avalanche

Douglas Hartley's 1994 Skoda Favourit Elta Pickup

A builder in the Ottawa EV community has hybridized both a Miata EV and a Cavalier EV:

Alain St-Yves' 1997 Chevrolet Cavalier

Building the "Zero-Carbon Car" out of a Miata, incl. biodiesel hybrid drivetrain

[Ryland]

Vehicles I would look at using would be a Dogde AWD minivan, the Honda Civic WagoVan, Toyota Corrola 4wd station wagon, or a 4wd Ford Ranger pickup truck.
If you get a 1996 or newer vehicle a friend of mine who is computer engineer likes the idea of working on an Arduino based OBDII plugged in motor controller, of course it's looking like tapping in to existing sensors might be just as easy and a bit cheaper.

[roflwaffle]

Originally Posted by bennelson

Anyone have some good links for other DIY Hybrids? Please post them here!

If I want to be able to "cruise" at 55mph+ and have the ability to do that at least some of the time on the motor, instead of the engine, I'll need to know how many horsepower are required to do that.

Can anyone help with some horsepower calculations? For now, let's assume that we want to use either a VW Rabbit Pickup, a Subaru Outback stationwagon, or Chevy S10 pickup truck. How many HP are needed to push those vehicles down the road at 55mph? Then we can find a motor - AC, DC, or brushless DC powerful enough to do that. We also need to figure in the RPM range of the motor for how it would be connected to the vehicle, and the gear ratio required. Does anyone have a link for a good HP calculator?

Once we figure on a motor, a matching controller can be found/bought/built to go with it.

The site power calculator is pretty good, just plug and chug the specifics (Cd, Crr, etc) of each vehicle.

In terms of the specific design, I'd shy away from a caddy because of the limited carrying capacity (~1000lbs IIRC). By the time the driver, motor, controller and rear end are in there you'll only have enough weight for about 25 miles of electric range.

Given LA batteries to start out with I think a better bet is something like a basjoos style compact body on a 4wd pickup truck frame. Put an old VW diesel engine in up front and hang a big DC motor behind the transmission. If someone is an absolute whiz with shift linkages, or if we could somehow adapt or create an automated shifter, we could shave off a hundred + pounds and increase overall efficiency by mounting the diesel drivetrain transversely, and doing the same to the electric but with a multispeed trans bolted to that as well. Old four speed manual transaxles don't weigh more than about fifty pounds or so, compared to the couple hundred a RWD drivetrain weighs, and multispeed transmissions can significantly increase DC motor efficiency at lower speeds/higher loads.