Ben Nelson's Electro-Metro Build thread

[bennelson]

(THREAD NOTE - ADDED 12/4/2009: Many of the original photos were posted through a .MAC web page. Later, Apple changed the name of their service to "Me", which wrecked everyones .Mac web pages, and broke many of the photo links early in this thread. Later photos were posted through other services and not effected.)

(EDIT: Note Added Sept. 23, 2010.
After all the work I put into this car, I decided to distill down everything I learned into an instructional DVD. If you are interested in building your own electric car, please support my open source, DIY projects by purchasing a video at 300MPG.org.)



OK- It's official.

I am starting a build thread for my next electric vehicle and I am doing it here.

The premise is this.
I am going to build an electric vehicle based on converting a street-legal four-wheeled automobile to run on a DC electric motor and battery pack. I need to do this as an ecological/economic project

The plan is to buy parts as I can, with cash, and only when I can find good deals. Recycled/Reused is highly encouraged.

The motor will come from a forklift and be over-volted as much as I can for a resonable, but not high top speed. The vehicle will be used for local travel, errands, and short commutes.

When finished, it will be something that neither I, nor my wife would be (terribly) embarassed to drive.

I will start off using free/existing controller, batteries, and other parts. When I know what I am doing, I will upgrade to either a purchased, or specially home-made controller. I plan to really look around to see what is possible for batteries. I will check with power utitites, firealarm companies, etc, to see if I can get used/surplus batts.

Planned vehicle will be a two seater. Most the time it will be driven by only me, but occasionally will have a passenger. I never plan on using it for four people.

I am thinking that either a compact car because of its light weight and small cost, or a light pickup truck for ease of work and repair, and battery-carrying strength.

I am only in the really early stages on this. I am currently working on buy the forklift which will supply the motor and other parts.

Next will be to decide what vehicle will work best, and then start looking around to find the deal on it.

Right now, please feel free to suggest what you think would be the best donor vehicle. Let me know why you think it would be best.

Thanks in advance,

-Ben

[bennelson]

Wow, I just put this up and I have something to add already.

I got a response from Jim at High Torque Electric.

He said that this forklift has a good motor, but the brushes and commutator are relatively undersized, thus it would be best for only a smaller vehicle.

Looks like if I use this motor, the vehicle will have to be more like a Geo Metro than an S10 or Ford Ranger.

All I really want is a roof and more wheels on the pavement than the electric motorcycle gives me.

I may end up going with a different motor than the one from this forklift. I am still planning on buying the forklift because it's such a deal and includes a BIG charger with it.

[bennelson]

I just starting poking through Craigslist for good cars with bad engines.

I found a 9 Neon for sale:
Craigslist link

Looks pretty good, only one little bit of rust on back. Price is right and it doesn't have a million miles on it. I don't know if it is stick or automatic.

What would you think of a vehicle like this one for an electric conversion?

I am guessing that it has two more doors than I need. An Neon owners out there that can comment?

[SVOboy]

Nice poking so far! I've finally understood your forum nickname, . I didn't get it before.

Anyway, what kind of stuff are you looking for in the car in terms of handling and sex appeal?

[MetroMPG]

Cool! Another EV build thread. I'm going to enjoy this immensely!

Since you're limited to a smallish car by the motor size, and you only need two seats, my first choice in superlight cars would be a CRX or Metro convertible. In normal light cars, a Toyota MR2 would be fun, or maybe a Miata. For cool, old & still relatively light: how about a Karmann Ghia or old Bug. Rabbit convertible?

I enviously eyed a dead Miata in a local junkyard shortly after we started working on the Metro...

However since you're operating on a strict budget, you may have to just choose
whatever comes up. But - get a car with a manual transmission (or one that you can replace with a manual from a junk yard).

I stopped over @ diyelectric car and read the good advice that Jim Husted provided. Man, that guy deserves a medal for all the help he gives people like us!

On the question of the charger, being an industrial machine, do you know if it needs a 120v or 240v hookup?

[MetroMPG]

What kind of performance are you going to be looking for? What are your minimum acceptable range & speed goals?

My suggestion: think about doing a 72 volt conversion. That will permit you to use a series/parallel setup with the 36v forklift controller for smooth, lower speeds @ 36v (2 strings of 36v in parallel mode), and switch to 72v (2 strings in series) for speed.

It'll also let you use your 36v charger - you can charge both strings in the pack in parallel mode.

Very exciting.

[bennelson]

I don't know if the charger needs 120 or 240. It was buried behind a bunch of other things - I could only get the view I did when I snapped a photo.

Friend of mine said it looked like a decent one.

Over at my parents house, there is a 240V jack in the garage for a welder. My gargage has a 100 amp fuse box it it. My garage is also in crumbly condition. I am hoping to rebuild it this summer. If I do, I plan on getting an electrician in there to wire up for anything I could ever want.

I talked to a guy a while back who had a forklift motor for sale. He also has several Miatas and about 8 Cub Cadets in his garage.
Maybe I could talk to him. A little electric convertable would be sooooo cool.

[MetroMPG]

Woo, Miata!

BTW - 72v worth of floodies is probably at the edge of GVWR limits for most small cars, and about the limit you can get away with before absolutely needing a suspension upgrade (stiffer springs), at least in a Metro.

[bennelson]

You are right on with 72 volts.

I figure, use what ya got.

This charger has a lot of amps, but only 36 volts.

I have been told that a forklift motor can easily have its voltage doubled or tripled.

Controller costs seem to jump up above 48 and above 72 volts.

72 volts seems like a reasonable way to go.

I would like to do 45 or 50 mph. I would like a 50 mile range, as one place I often work is exactly 25 miles each way. I know that is asking a bit much on a budget converson.

I do not need to take this car on the highway, but do need to go fast enough for some large country roads.

[bennelson]

I just looked up some info on the Miata.

I hadn't thought about it, but the Miata is rear-wheel drive/longitudinal engine - the same as how many pickup trucks are.

I thought one thing that would be nice about a pickup conversion is how the motor would attach to the transmission would be a little simpler.

A Miata sure would weigh a lot less than a pickup and be cooler to boot.

A 72 volt battery pack by using Trojan T-145 flooded lead acid batteries would weigh 864 lbs.

Here is a Miata conversion using Optima 12 volts to sacrifice range for speed. I think I would want to flip that and get more range/less speed. Not that I want no speed, but it would be an acceptable trade-off for better range and low cost