Geo Metro plug-in parallel hybrid EV - in progress

[Coyote X]

I should be filling up my car tomorrow and be back in the 50 mpg range with it hopefully this tank if nothing else unknown is wrong with it. So it is pretty much ready for normal use. My long term goals have always been to add electric drive to the car somehow though.

So my criteria for how to do it are that it needs a a small set of batteries and would like to keep the costs reasonable. Reasonable meaning I would like to stay under $5000 if possible. My car is ~1500lbs right now so with me and any random junk in it I would say a maximum load of 2000lbs as it is now. I don't have lots of room inside the car to put stuff and taking up what little room is left with batteries would suck. My goal would be able to start and run only electric drive for 5 minutes at 35mph. Any longer or faster would be a bonus but if I can do that then I'm happy.

For the motor and controller this one seems like a good setup to me Mars Brushless PMAC Motor with 250A Controller Kit and is complete for 1500 bucks. The only clue I have about what is needed is an online calculator that says it will pull 150 amps at 50mph flat ground with the weight of my car put in it. AGM batteries seem like a good choice since they are a bit stronger than regular deep cycle marine batteries. But maybe optima or some other types would be better?

With that controller I can run 48V and that is a good voltage range to modify the alternator to charge them if needed. I plan on not charging them with the gas engine most of the time but having the flexibility to be able to might be nice. A 48V charger would not be hard to either find or make to charge it at home. I could also Cover the trunk and hood with solar panels even though they would cost way more than they would be worth really.

As far as connecting the motor to the drive. I can add a sprocket to the drivers side cv axle and put the motor over top of the transmission. It would spin all the time while driving but that should not be much of an issue. I am not sure if it is possible to rig a clutch up to it to keep it from always having to spin. The suspension doesn't have much travel so the drive chain would not have any issues with binding or slack. I have read that a brushed DC motor would not work well spinning as fast as I would be driving it while under gas power. The brushless motor seems like it tolerates high rpms better according to it's specs.

So enough rambling. Does anyone think it would work or am I way off? I am not committed to buying any of the stuff I listed or even mounting it like I described. I am mainly trying to plan what to do and experiment with a spare Metro this winter and start putting it in my good Metro this spring. ٩(͡๏̯͡๏)۶

[MetroMPG]

Cool - if anyone's going to follow through with this, it would be Coyote X.

Hope you don't mind I changed the subject line a bit. It really would be a hybrid...

Originally Posted by Coyote X

My goal would be able to start and run only electric drive for 5 minutes at 35mph. Any longer or faster would be a bonus but if I can do that then I'm happy.

That's totally achieveable with the parts you linked and 48v worth of either floodies or AGM batts. (Optimas are AGM.) Another benefit of AGM is you can mount in any orientation - they won't spill - so "packaging" is easier.

The only clue I have about what is needed is an online calculator that says it will pull 150 amps at 50mph flat ground with the weight of my car put in it.

FYI, the ForkenSwift pulls roughly 70-100A @ 48v to go 30-35 mph. That's with a less efficient motor, heavier (2070 lbs) car, and horrid rolling resistance (snow tires... in the summer).

As far as connecting the motor to the drive. I can add a sprocket to the drivers side cv axle and put the motor over top of the transmission. It would spin all the time

The motor & controller you linked to can do regen, so that may not be a bad thing to have direct drive, always turning. Though the rule of thumb is to expect only about a 10% range increase with a regen system.

What about a sprag/freewheeling clutch? Maybe a little less parasitic drag, and you could potentially use a cheaper brushed motor/controller.

This is totally do-able. I think about it often and want to do the same thing to the Flea, though it's further off in the future than next year if at all.

Another thought: what about using the 5th gear shafts on the end of the transmission? http://ecomodder.com/forum/showthrea...-fwd-1605.html

[ZeroFuel]

Hey Coyote X

Good luck on your project. I would suggest if you haven't seen it yet is the link I am enclosing from the Cornell X Prize team. They have a mule that will be substantially modified, but on their first attempt they only achieved mid 40's. I'm sure your getting much more on your ICE. Weight is a big issue.

Cornell AXP Mule: PHEV Geo Metro - X Prize Cars

[Christopher Jordan]

Originally Posted by Coyote X

. Reasonable meaning I would like to stay under $5000 if possible. ....My goal would be able to start and run only electric drive for 5 minutes at 35mph. Any longer or faster would be a bonus but if I can do that then I'm happy.

With that controller I can run 48V and that is a good voltage. A 48V charger would not be hard to either find or make to charge it at home.۶

Today I will make you a great deal! For $4999.99 I can sell you a 50 mph, 48V (four chargers onboard) City-el!

I finally got new tires on it and an idiot light began flashing. I took the lid off to check connections on the lower 3 batteries and darn near had heart failure; then got angry since I could not believe the wires, blocks, relays, clips, and more. MORE than a car. An electrician who saw it could not believe it! Multiplied problems many many times. I will not touch it.

I just closed the lid annoyed- with that mess. I asked at the P-A Group whether City-el will ever come to the US hoping to get another "normal" one
Everything works great, just ignore the flashing light. I'm not sure about going the classified ad route and waiting 6 months for a lowball offer. So much for that EV. I have enough trouble charging it her sneakily because the complex does not allow it.

[Coyote X]

I thought about the 5th gear shaft or using a rear wheel to drive the electric. But it pretty much came down to keeping it simple, reliable, and easy to work on. If I modify the trans and something happens later on I will have to remake a lot of parts. Or at least have a huge mess trying to take it apart when I have to work on it in the future. Same thing with finding a euro awd swift and using the rear drive. When I need a part it will take a month to get it shipped so maintaining it in the future would suck.

The main thing about attaching the drive to a cv axle is that it really won't make anything else harder to work on. At most I would have to swap the axle shaft over to a different halfshaft assembly to keep from having to remake the sprocket mount. If I do make it then it will be on a new half shaft so I should be good for 150k miles before having to deal with it. The sprockets and chain will wear about like any good O-ring chain and I figure 25k miles out of it. If I use a master link on the chain I could also just take the chain off if anything happens to the electric drive and it needs disabled to get the car home. Making the sprocket mount should be pretty easy. Just find a non cushioned drive motorcycle rear wheel hub that has an axle shaft size big enough to stick the cv axle through and center and weld it solid. The sprockets are big enough to slide over the cv joint and bolt to the hub when they wear enough to need replaced.

[bbjsw10]

Originally Posted by Coyote X

Making the sprocket mount should be pretty easy. Just find a non cushioned drive motorcycle rear wheel hub that has an axle shaft size big enough to stick the cv axle through and center and weld it solid. The sprockets are big enough to slide over the cv joint and bolt to the hub when they wear enough to need replaced.

The nice thing about this as well would be sprocket selection, tons of them on the market of different teeth count.

Good luck on your project. If you get it done for Geopalooza next year you should bring it by.

[metroschultz]

When I left you had an engine and trans combo laying on the floor to use as a mock-up guide.
I thought by now you would at least have a bracket hammered out for the elctric drive and a sprocket welded to one of the half shafts just to see how it all would fit.

We all have faith that you will make it work.
"You can do eeet"
Schultz

[bennelson]

Well, I have both an Electric Geo Metro, and an electric motorcycle with almost the exact same motor and the one suggested, so I will weigh in on the topic.

>Battery Weight
>Motor Gearing
>Where do you put the motor?

I think one limitation you will have is space - where the batteries go, and where the motor goes. The Etek is a very compact motor, but it still has to be spaced and mounted. You also need room for the motor controller, and charger if you want to recharge while out and about. Since you will have gas power, figuring out charging and regen braking would be pretty slick. Kelly controllers have a regen feature available. A Permanent magnet motor like the Etek RT could be used for regen.

Please keep motor gearing in mind. Electric motors want to spin fast with less load to be efficient. My motorcycle has about a 6;1 great ratio on it. It has plenty of power. I have heard of guys using higher gear ratios, and burning out their motors because of it. Faster spinning motor = less amps = better range and happy equipment.

I have 450 lbs of lead in my car, and I can go 20 miles on a charge.


I mostly have space for everything in my car because all the gas stuff is out of the way. I would be a challenge to fit everything in as a hybrid. Not saying you can't do it, just that it might be a puzzle!

You might want a higher amp controller. Keep in mind that most controllers are rated at their "peak" amperage - the power they can put through for only a minute.

Also, if you are using the electric for pulling away from stops and getting going, that's when you are pulling a lot of amps. A higher amp controller means better acceleration.

I really don't know what the best place to put the motor is, just make sure it's mounted solid and geared down well!!!

AWESOME project!

[MetroMPG]

Originally Posted by bennelson

I think one limitation you will have is space - where the batteries go, and where the motor goes.

Ever seen the hood on the Volt mule?



I've thought some bodywork like that might be needed to mount a motor on top of the transaxle to drive either the 5th gear shaft or the driver's side axle.

[bennelson]

Actually, and Etek sticking up through the hood would air-cool the motor AND look pretty cool, but you would take an aero-hit at high speeds.