[ClintK]

I'm a school teacher, so I don't have a huge budget for this. Any idea where I can get a REALLY cheap forklift to take parts from to start my conversion on a 1994 Saturn? I really want to do this, but it seems everyone spends $10,000 to make a conversion. Not bad for a new car, but money is one of the reasons I want to try a conversion, the other being fun of doing the job!

I've seen many conversions done for $3000 (and some much less!). It's definitely doable depending on your goals. Home made adapter plate, creative solutions for a coupler, used fork lift motor, lower end Kelly/Alltrax controller, and Walmart batteries - you can do it.

I'll let someone more experienced with fork lifts than I to suggest where to buy a motor. All I can think of is junk yards.

 

[Coley]

Ebay comes to mind, also if you have any small factories nearby, check with them to see if they have any old forklifts they would like to get rid of.

Scrap yards for forklifts is a good place also.

A fellow called the other day about a GE motor on eBay that was capable of running on 48 volts and making 10 HP. The price was $100.00.
I told him to get it, as he could drive over and pick it up.

They show up there from time to time.

I started with a 5HP and 48 volt.

The car was given to me which kept the price down.

Used batteries can be had as well.

Controllers are on ebay also.

 

[DavidDymaxion]

I've heard some folks scavenge used batteries from hospital equipment, or computer uninterruptible power supplies, or golf courses. Another thought is trying to scavenge Optima Yellow or Blue top batteries from car junk yards. Sometimes all a "dead" battery needs is a good charging to get going. Warning: You can get car starting batteries cheap, but they'll only last about a dozen cycles. You really need a deep cycle battery.

I've heard BMW cars put the battery in the trunk, and have a heavy duty battery cable that runs the length of the car. Given welding cable can be as much as $10/foot, this would be a great place to save some money.

Some folks have made battery terminals by crimping copper pipe over the cable, and drilling holes. They then wrap it around the terminal and use a bolt to cinch it on.

How fast do you need to go? A 3 step golf car controller might be enough control if you keep the gears.

My car currently has eight 12 Volt batteries, and I estimate I'm about $4k to $5k into converting the car, with all new parts. I saved a lot of money by doing my own adapter and by going with a custom WWI era technology controller. It would be OK as a city car, but needs more parts and money to be a freeway capable and 40 mile range daily driver.

 

[cdtomlinson]

Right now I live about 6 miles from work, but plan to move to a school that is 20 miles down a state hwy (60 mph zone) the other direction. The country here is really hilly, so I don't know how much that affects range. The town 20 miles away is where I go for 80% of my driving anyway, so getting there and back would be great. I think to not cause any big grief, I should shout for 50mph at least. Is there a formula or anything dealing with weight, volts, whatever other factors in the car to decide range and speed?

Also, I am quite capable of making my own adapters and mounts and I am adept at soldering if I have to repair or built a controller, though I am not able to design one.

 

[Guest]

Welding cable is the best way to go for that part of the build. Battery cable is not the best. It is built for a few quick shots of power to start a vehicle and not sustained amperage for a long time. All in all the welding cable is a small portion of the cost of a conversion.

Pete

 

[cdtomlinson]

You mentioned cable, could you use battery cables instead of welding cable if you had a long enough piece? The issue I imagine would be the current it would have to carry.

 

[Guest]

Fine Wire welding cable is high quality, and designed for high amperage and voltage for sustained periods of time. I have used battery cables for jumpers on my electric motors and they get hot fast at sustained speeds. I even have a set of jumpers and at 6 volts from my NiCD battery will get hot within minutes running my series motor. You do not want cheap o cables in you're conversion. Go to your local welding supplier and get the fine wire welding cable. Many here use 2/0 size cable. Some use 4/0. I use 2/0 through out my conversion. Works for me.

Pete

 

[DavidDymaxion]

Good points, I should have mentioned this stuff. Most battery cable is too small a diameter -- I literally explosively blew off a battery cable segment during some testing! It got pretty hot in my earlier tests, even on fairly modest currents of 100 to 200 Amps. In contrast, my 4/0 welding cable stays cold to the touch, while a segment of 1/0 got a bit hot on my race run. I believe the BMW cable is thicker than normal, since it is such a long run. In any case, if you go scavenging for cable, measure the diameter of the conductor (repeat, the conductor, not including the insulation) and compare that to a wire current capacity chart.

Battery cable and <shudder> home wiring is stiffer and harder to work with than welding cable. The many fine strands of welding cable make it more flexible, and it is designed to be dragged about.

Fine Wire welding cable is high quality, and designed for high amperage and voltage for sustained periods of time. I have used battery cables for jumpers on my electric motors and they get hot fast at sustained speeds. I even have a set of jumpers and at 6 volts from my NiCD battery will get hot within minutes running my series motor. You do not want cheap o cables in you're conversion. Go to your local welding supplier and get the fine wire welding cable. Many here use 2/0 size cable. Some use 4/0. I use 2/0 through out my conversion. Works for me.

Pete

 

[madderscience]

Even if you buy largely new stuff, as long as you stay with a 72V rated components, you can keep to more like $5000 in parts even if most things are sourced new, instead of the $10K or so for the 120 - 144v DC conversions. This is largely because you are now in golf cart territory and you have many cheaper options in terms of controllers, contactors, etc.

an 84V (some 72V alltrax and curtis controllers can apparently be safely overvolted to 84V) 3 door 1990s geo metro (basically the smallest, lightest car you can possibly find) with a 6.7" DC motor (D&D sells them, or there are forklift motors in this category), an ebay controller and golf cart DC/DC, breakers, fuses, etc and fourteen, 6V flooded batteries (roughly 840lbs) or seven 12V flooded batteries (roughly 560lbs) should stay in fairly low budget territory and still be a usable car.

Said geo with the 12V batteries would probably end up weighing only about 2000lbs, and with the 6V batteries, 2300lbs, well within what the suspension and brakes can handle. You'll probably have about 25 miles of useful range on the 12V batteries and 35 to 40 on the 6V ones.

Hit a few golf courses and see if they have any decommissioned golf carts or spare batteries with life in them. take a specific gravity meter and a volt meter and know how to use them if looking for batteries this way. Tip: flooded batteries have a date stamp on one of their terminals (forget which) that will tell you how old the batteries are. Anything older than 3 or 4 years probably isn't worth much. I don't remember off the top of my head, but you can contact the battery manufacturers or a local battery shop to figure out how to read the date code.

I agree with the comments regarding welding cable; don't use anything else. 1/0 is probably OK in a very small car but 2/0 is what most people use. I bought mine (new) for about $3 a foot from an industrial supply warehouse that looks like the sort of place that would have king tut stashed in a corner next to the ark of the covenant. Stay away from retail with that stuff. $10/foot is highway robbery.

Biggest downside of an 72/84V conversion is top speed isn't going to be very good, especially on the hills. with a really light car and the small diameter motor and 84V, in 5th gear 55 is probably the best top speed you can expect; but you will be pulling quite a few amps due to the low voltage system.

Whatever you do, do not compromise safety and reliability (in that order). doesn't matter how cheap you managed to build it, if it is undriveable or it hurts you or somebody else, it was still a waste of money.

Go to a local EVA meeting if any chapter is nearby and see who can offer advice and a garage full of parts to sell cheap.

Another option is to watch ebay and craigslist for an already-built conversion that needs a rehab. Most commonly they need batteries and frequently a new controller. There have been several on the seattle craigslist recently ranging from $1000 to $3000; but in all cases they needed at least a couple thousand in work to be runnable, but still well under $10K. Ensure whatever you get if you go this route was well done with appropriate parts to begin with, or it may not be worth it unless you are just buying it for the parts.

Good Luck

 

[Guest]

an 84V (some 72V alltrax and curtis controllers can apparently be safely overvolted to 84V)

Actually it is not advised to over volt them. The 84 volts you see on the controller is the max voltage of lets say a 72 volt system. When the pack is fully charged you will be in the max range of 82 to 84 volts and at the upper limits of the controller. If you add any extra batteries to get a nominal voltage of 84 volts then you will be in the 90 volt range when fully charged and will risk opening that secret door in the controller and let out all that precious secret smoke that makes them work.

If you have a 72 volt controller stay with 72 volts. If you want more go with a controller that will allow you to run at higher voltages like the Synkromotive controller. It will allow you to operate at voltage ranges from 72 volts to 156 volts nominal pack voltages then decide which voltage range you want from there. You also must remember that you need to charge your pack too. Chargers are not cheap and multiple chargers are just a plain pain in the butt. One charger, one pack to charge. If you go 72 volts you will most likely want to stay on flat ground and stay within 55 mph or slower. It is considered the very minimum voltage for a decent street ev. For freeway speeds you will want more voltages. Most want the ability to do some freeway driving so I'd consider from the start to go with a higher voltage. Plan on it. I did and went from 72 to 96 posthaste and found I want even more. I have the controller to do it too. In order for me to safely go any higher voltages I will need lithium batteries because I am limited in space and weight capacity in my VW Ghia. I could go with 12 volt batteries but I want the distance too.

Pete

There is lots to think about before you build. Be sure what you want before you spend your hard earned money. It will save you a bundle. Upgrading can be expensive.

 

[Guest]

A fun around town car only can be done very well with 72 volts. And it will be cheaper than a higher voltage vehicle.

Pete

School projects like this are done all the time.

 

[cdtomlinson]

Thanks for all the input. Is there a list or site anywhere to tell me where the nearest EV meeting would be? I really want to do this, but have to work out the budget side of it before I start.

 

[electromet]

Try the Electric Automobile Association at www.eaaev.org. They show two chapters in Missouri, with KC probably the closest to you.

Mike