Geo Metro plug-in parallel hybrid EV - in progress

[roflwaffle]

GL! I'm really curious about how well the welded sprocket will hold up since that would make things a lot easier.

[metroschultz]

Hey Rick,
Would you please put up a list of parts and prices.
Probably in the first post to make finding it easier.
I am following with interest and would like to know what you've got invested money wise.
Thanx,
S.

[Coyote X]

I can't edit the first post. Guess the permissions of the board are set to not allow edits after so long. I have all of the expensive parts purchased already so I can list that part of it.

PMSM Motor for Burnisher Motor was $450+40 shipping
Batteries are Everstart Maxx Marine deep cycle/starting batteries. $70 x 6
https://www.kellycontroller.com/shop...product_id=115 KBL72301 controller $550 + 40 shipping
https://www.kellycontroller.com/shop...product_id=450 72V,8A charger $200 shipped with the controller.
X00078R [Shoup Manufacturing Company] Sprockets $73

Misc stuff:
2 battery boxes $8 ea
12 Terminals $2 ea
Wire ? have to find it first
Chain, Prob get a #50 chain from Lowes for $25 to make sure everything is good. Then get a good 530 O-ring chain ~$100
GameCube controller to cut apart for the analog triggers ~$10
Random wiring and switches I already have.
Parts for battery balancer circuit ~$75
Alternator Mods ~$25

Total so far: $2,000

So I arbitrarily picked $5,000 at the start of this thinking buying all new parts would cost a bit more. Guess I came in under budget. I am not done yet so it might get more expensive. I might have to build an idler shaft if the gearing doesn't work out right. I know the batteries I picked are pretty cheap so it will limit my electric only range. Getting good batteries are more like $200 each for optima yellow tops. I plan on going to LiFePO4 next summer so that is the reason for picking those batteries. If I add solar cells to it then I am looking at another $350 added to it.

The welded sprockets are really heavy so I don't see how they could possibly fail. They are made for tractor attachment use. So they can handle 100hp PTO drives. The mars brushless motor can put out 15hp so I should be well within the safe range of power. I guess I will find out when I start driving it

[roflwaffle]

When I was looking at it I wondered whether or not I could get enough penetration/metal on there to keep it on with ~100ftlbs of torque w/o screwing up the CV. Otoh, too little M/P and the sprocket could come off. Maybe I'm thinking the CV is dinkier than it really is.

Edit-I finally remembered why I didn't want to put it on the CV shaft. If the weight in the car changes appreciably then the CV shaft angle will change, wouldn't this require some sort of electric motor mount mechanism to keep the chain lined up? If the sprocket is on the flange/end of the CV before the joint, as opposed to the shaft, then changes in ride height aren't a problem.

[Coyote X]

If there is a lot of movement where the sprocket is attached to the cv shaft then it would probably be a lot of work to get the chain to stay on and not jump off or wear out quickly.

My car has been lowered and only has about a half inch of travel before hitting the bumpstops. So I have a pretty small amount of movement up and down. There is a bit of front to back movement from the wheels steering. But in total there is less than an inch of movement so that is fine for a chain drive setup. The main thing that seems to kill a chain is a twisting motion that stresses the links.

I really wanted to put the sprocket on the axle hub sticking out of the transmission but there just isn't much room to get a sprocket around the hub without hitting the trans. I figure putting it on the axle shaft is a compromise and if it doesn't work then I am only out like 20 bucks trying it out so no big loss really. I don't think it will be a problem though. I guess I will know for sure next week after it is all put together.

The batteries are all here, the motor and sprockets are here, the controller is on it's way and will be here in a day or two, and all that is left is I need some chain and some wire. Spring break starts next week so I am hoping to get it basically done next week.

[Blue Bomber Man]

Little late since you have your batteries already but I found a site that has the Thundersky batteries for $80 a piece, 40Ah 3.2V a piece. 1.5kg each, but I imagine you need 15+ for the voltage you need (I didn't check to see what you were running into your motor).

Electric Motorsport EV Parts :: Thunder Sky Batteries

[Coyote X]

Made a tray to fit the two batteries that go behind the seat. The way the caps are made it won't be hard to attach a hose to them to vent them under the car. I will probably make a cover of some sort to hide them. They don't look that good back there.

The controller and battery charger should be in tomorrow. I decided to get a jump on spring break and start on some of the easier things today. I have some time tomorrow so I will try to get the rear battery tray built and stick a different set of springs under it to get it sitting level again. Hopefully this weekend I will be able to get the sprockets and motor mounted up. I am thinking of taking the dashboard out when I wire up the controller. There are a few issues I need to look at anyway and it would be a good time to get everything sorted out and working.

[Coyote X]

Originally Posted by Blue Bomber Man

I didn't check to see what you were running into your motor.

Running 72V. From what I can tell the Mars motor really won't live long if I exceed 72V 300A on a regular basis. So keeping the voltage and current at the proper limit should give me a nice long service life out of the motor hopefully.

[Blue Bomber Man]

So 22 of those puppies would get you to your voltage and also give you 880Ah's for a weight of 73 pounds. Of course this would run you about $1800 total and you would still need the BMS. I don't know the stats for your setup but I would bet that would be 20-40 miles of all electric range at city speeds.

I could run the numbers through a spread sheet for you if you want. I would need to know Cd, Frontal Area, vehicle weight, estimate of rolling resistance of your tires (if you don't know I will just throw a reasonable number there), electric motor efficiency (usually around 90%).

My numbers though will assume no drag from the cars normal engine hookup.

If you want me to run the numbers for the batteries you got I can do that as well.

[Coyote X]

Cd .360 hatchback. Prob ~.390 for a 'vert with the top up.
Frontal Area 1750 m2
vehicle weight prob 2000lbs total
rolling resistance of your tires Sumitomo htr tires 0.0092
electric motor efficiency (usually around 90%). sounds good

The batteries I got are pretty weak. Exide Maxx 125A@20hr but they are light so I figure they won't handle high current well and I would be lucky to get half that under load. I mainly got them because of the 18 month warranty. The guy said he didn't care what I did with the batteries, if they die before 18 months bring it back and get new ones. So they will do me for now and once lithium batteries are cheaper I will go to them and use the walmart batteries for other cars and things.