Who knows something about electric cars?

I'm needing some ideas for a low (ish) budget electric drivetrain.

We've got an idea for onboard generation that could produce about 1kw. Any drivetrain/ storage ideas, or estimates of what we could accomplish with this?

I may be out of the Challenge budget, but I wouldn't mind trying.

I haven't played much with 'lectric cars.

I got excited about trying to build an electric about a year ago but realized that to do it right would be more than I wanted to spend. Google it if you haven't already. There's a world of info. there including some useful forums and hardware suppliers. Good luck and please keep us posted.

http://forkenswift.com/

I burned up my golf cart at the last lemons race. Does that count?

Seriously, I know the basics. The big question is how fast do you want to go.

I still have a couple of motors in my shop from a project I was considering years ago. What brought me to a screeching halt was the controller. Ten years ago they were well over a grand and out of my budget.

My plan was to run a forklift motor through a stock 5 speed transmission. That way I wouldn't have to hit the gearing dead on. Not the most efficient rout, but it was in my budget.

There is a pile of info on the web, and google is your friend. One day in the distant future I'll build one. For now, I guess I just fix the golf cart.

Zomby woof wrote: http://forkenswift.com/

Cool site. Now I'll have to look into EVs again. Thanks for that.

Diyelectriccar.com

The NEDRA guys specialize in cars with a 1/4 mile range, but some of their links might still be useful to you

http://www.e-volks.com/about.html?

Looks like it would be one of the easiest and cheapest to do. A VW van would be cool with tons of battery storage.

-Rob

toyman01 said: Seriously, I know the basics. The big question is how fast and/or far do you want to go.

fixed that for ya.

the basics are pretty simple... mount an electric motor to the stock trans of whatever trans the car has (manual gearbox please), wire up a bunch of batteries... how you wire them depends on your choice of how far or how fast you want to go, wire up your controller and go...

small pick ups are also a fav for the EV crowd... easy location to mount a bunch of batteries... not hard to find with no power options (power steering requires more work to run the PS pump or an electric PS pump, power brakes require an electric vac pump.

there was an EV s10 in hotrod mag that was doing 10sec 1/4 mile passes or something like that... want to say he had over $5000 worth of batteries in that thing to do it though

wish i could figure out where they got the electric motor at school.
Teacher has one of the coolest project's I've seen: audi tt quattro, manual transmission, with a gigantic electric motor (about 240 tq supposedly) bolted up to the stock transmission. So it's going to be an awd manual transmission electric vehicle.

Way back when (late 1970's), there was a guy who built several DIY electric cars and they were featured in Popular Mechanics etc. His biggest stumbling block was a throttle which would allow smooth acceleration, somehow he wound up using a four brush Lucas starter to build what he called a 'chopper'. It pulsed the electric current for the main motor until the big high power contactor kicked in. Other than that, it was pretty much off the shelf forklift stuff.

$5K for a battery is nothing in the EV world . That might get you a good used 36V battery for a small forklift. That would be for a plain old lead/acid deep cycle batt. I work in the electric forklift buisness, and I hope that EV cars make it in to the main stream soon . Everything they need execpt light weight batteries has been in the forklift industry for ages. Do you think the Tesla roadsters A/C drive system is impressive? A/C drive forklifts have been around for over 15 years . D/C drives with seperatly MOSFET controlled armatures and fields are pretty good too. There also electric forklifts that have completly given up their lead/acid batteries in favor of hydrogen fuel cells and lithium batteries.

Curmudgeon wrote: Way back when (late 1970's), there was a guy who built several DIY electric cars and they were featured in Popular Mechanics etc. His biggest stumbling block was a throttle which would allow smooth acceleration, somehow he wound up using a four brush Lucas starter to build what he called a 'chopper'. It pulsed the electric current for the main motor until the big high power contactor kicked in. Other than that, it was pretty much off the shelf forklift stuff.

If that was realy in the late 70s that guy was behind the times, he could have used off the shelf GE EV 1 forklift parts to do that . I might have to do some research, but I think that was on the market by '77. Btw GE never made a forklift, just motors and controll systems, in fact GE EV controll systems are the SBC engine of the electric forklift industry.

Li-poly batteries cost $ 1000/kWh and weigh 20 lbs/kWh now for just the cell packs. At even 25C you can draw more power than you can use; 25C means full discharge in 2 1/2 minutes.

Think very carefully about how far and how fast you want to travel. A compact passenger car uses about 20 hp at 65 mph, so you need 15 kWh to run it for a full hour. That's a heavy (300 lbs), expensive ($15,000) battery. Cut the power requirement to 10 hp and you cut $7500 out of the battery cost; same goes for cutting the range by half. Regenerative braking helps in town if you have front-wheel-drive and can engage it before the normal brakes come in. Burst power is free aside from motor and wire weight; at 25C a 15 kWh battery gives 375 kW (500 hp).

You will need a battery management system; Lithiumate builds an OK one but I bet the designers never figured on drawing 200A/cell on a 105-degree day out in the Texas sun, so it let a couple cells cook. You will also have to think of a good way to charge it and keep it cool during charging. The Lithiumate BMS costs around $2000 and the chargers aren't terribly cheap or expensive.

You will want to design the cell mounting carefully. Think about how far the heat and burning liquid from a burst and burning cell travels; can you keep it from lighting off the other cells? If the battery burns, is it a large enough fraction of the car value that you may as well let it torch the rest of the car?

Avoid Kelly controllers like the plague. We have put blood, sweat, and tears into them and they have let us down every time. The throttle response is the pits and they never let full power to be really used. They're made in China and consequently many weeks away anyway. If you use a brushed motor there are many options.

Don't be afraid of high voltages as a designer; it cuts down on the heat you have to dissipate, and most of the components are already rated for more voltage than you'll be dealing with. Do be afraid of high voltages as a car builder or mechanic, as it gets dead-before-you-hit-the-floor dangerous.

The last three Formula Hybrid seasons have been won using a Perm-132 electric motor; about 30 lbs, about 35 peak horsepower. That may be mostly because Texas A&M and Politecnico di Torino used them, though.

One really cool possibility for the grassroots builder would be figuring out how to use Prius components.

The battery's 1.8 kWh, weighs around 120 lbs, costs $600 at the junkyard, which is far, far cheaper than any other solution. Similar stories go for the motor, controller (goes for $300), and wiring. If you can make it like its new non-Prius home you will have won the hard part of the battle.

To point out the obvious, the Hybrid Fiero that competed in GRM $2009 had prius batteries, but one prius pack doesnt get you far or fast by a long shot.

I have a project using prius batteries to make my Caravan a hybrid.. and AWD, and Manual, for the guy mentioning the TT. And im working on a certification to teach automotive. Small world.

fhalA wrote: I think a vw is a good idea.cheap and loads of battery storage.By the way have you heard?there is no love lost between the hosts of television show “Top Gear” and green automobile makers. A dismal overview of the Nissan Motors Leaf has started a new beef amongst the BBC show and Nissan Motors.If you wanna know more check out this article source: Top Gear starts new electric car quarrel over Nissan Leaf

Osterkraut wrote:

fhalA wrote: I think a vw is a good idea.cheap and loads of battery storage.By the way have you heard?there is no love lost between the hosts of television show “Top Gear” and green automobile makers. A dismal overview of the Nissan Motors Leaf has started a new beef amongst the BBC show and Nissan Motors.If you wanna know more check out this article source: Top Gear starts new electric car quarrel over Nissan Leaf

Glad someone else caught that. We've had to delete four other canoes by this user in the past....the thing is, the people behind this are a little more careful to use complete sentences and spam a related thread. Never the less, they need sinking.

A couple years ago, on the Team ZX2 site, a fellow built an electic ZX2. Very nice professional job. He use car batteries connected to produce the necc. voltage. He sourced almost all used parts. So some one could do a search on that site for info.

I hate to E36 M3 in the punch bowl, but isn't 1kw only about 1.3hp? Are you planning on using a whole bunch of these on board generating devices? Is it going to run all the time and charge a battery 24/7? That would allow a lot more instantaneous power, giving your vehicle a bit of acceleration.

Have you checked your local Barnes and Noble (Borders is going out of business - they might have books for cheap!)? Their automotive section, typically has at least one 'build your own electric car' book. Your local public library might have some books too. When I was at the library a couple of months ago looking for the service manual for a friend's Neon (yes, my library has factory service manuals!) I saw a couple of those books. They had a few from the 1970's gas crisis era, and a few new ones.

Good luck,
Bob

Skip the EV build and put your 1kw device on an insight or Prius to demo it, seems like the easy route.

Typo. 10kw. Yes, it will run all the time.

So, it is an opportunity to augment the batteries, not a sole source. Of course, that is assuming there ARE batteries!

Vehicle will be sub 1000 lbs, so the power needs are much less than many EV's.

But if I told you ALL the details, I'd have to kill you!

not relevent to the OP ... just sumthin' to get y'all amped up

11 sec. electric drag car

http://www.youtube.com/watch?v=UAYrsEOxqYc

chaparral wrote: You will need a battery management system; Lithiumate builds an OK one but I bet the designers never figured on drawing 200A/cell on a 105-degree day out in the Texas sun, so it let a couple cells cook.

(105 F= 40 C)

To answer your question:

A) The Elithion Lithiumate BMS does monitor the temperature of each and every cell, and it controls the shuts down of the battery if any cell is too hot (default is 60 C, but it can be adjusted by the installer).

B) The Elithion Lithiumate BMS includes a fan driver, that turns on whenever any cell temperature exceeds a set value, to cool down cells that heated up during operation.

chaparral wrote: The last three Formula Hybrid seasons have been won using a Perm-132 electric motor; about 30 lbs, about 35 peak horsepower. That may be mostly because Texas A&M and Politecnico di Torino used them, though.

And, by the way, both winning teams used a Lithiumate BMS.