Electric tractor

[bill177]

I have been reading up on the subject of electric cars - the kind you do the converison work on yourself. All this got me thinking about doind a conversion on a tractor.

For short jobs - which most of mine are - I think there might be some fire amongst the smoke and mirrors of the battery operated technology.

I till my garden in about 30 minutes (30 x 70). That is twice a year. I use the bucket loader a couple of hours a week for various "stuff" moving. Weekly trips to the burn barrel. Even snow moving takes me no more than an hour at a time.

All told, I probably put a hundred hours on the tractor a year. Again, mostly short jobs.

Finding a runout tractor around here is not a problem. They can be found all over the place. Engines are shot and there is no interest in rebuilding them.

Well, enough air castles - anyone else ever give thought to a project like this?

 

[2manyrocks]

Apparently, it has already been done.

Electric Tractors on Small Farms

 

[ToadHill]

When I worked in industry the company I worked for made electric motors, both AC and DC. Many of the DC motors were what were called Traction motors. They were used in rapid transit rail systems and both powered the rail car and acted as the brakes.

If they could power these heavy cars it would stand to reason they could be made to power a tractor. The battery pack could certainly add to the weight of the machine.

Many of the very large earth moving machines that run diesel engines actually have traction motors driving the wheels and the diesel engine powers a DC generator.

 

[EddieWalker]

LaTourno was a big time, heavy equipment builder back in the 40's all the way to today. His company still makes some of the larger mining equipment there is. He invented hydrualics on a dozer blade and the self propelled belly scraper. In his modifications and improvements to the scraper, he came up with putting electic motors at each wheel. He said that the electric motor has so much more power then a diesel engine, that it was the logical thing to do. Of course, that was before modern hydraulics, and I don't know anything about electric motors. He used the diesel engine to generate electicity and the electric motors to turn the wheels.

The problem I think you'll have is getting electric motors big enough to do the job and then having enough electicity to power them.

Eddie

 

[IXLR8]

My neighbor, when I lived in Conn., had 2 GE electric lawn tractors, they were totally electric, 4 batteries I think, he loved them. I have no idea if they had more tractor ability than just mowing lawns, no idea what happened to them, haven't seen him in 8 years.

 

[Wayne County Hose]

Interesting idea. The one big drawback for you is the limited use. The batteries in a high draw machine such as this are made to be discharged down to 80% discharged, rested 8 hours, then charged. Your application would be very similar to a forklift application. For short uses, less than 4 hours a day, you are far better off with an IC power. You would destroy a set of batteries in a couple years using them the way you would like. The other alternative is to use an IC powered generator to power the motors, which defeats the purpose of installing electric motors in the first place.
Forklift electric motors would have plenty of power for something like this. Just go into one of those warehouse clubs like Sam's club and watch the little 3 wheel electric forklifts lift up 3,000 lbs pallets, plus they are lifting the weight of the mast which is another 1500+ lbs. And these are the little 3 wheelers, you should see the 4 wheelers.
Unless you have quite a bit of knowledge in electric motor controllers and their technology, and a place to access the parts pretty cheap, I wouldn't even bother.
I had entertained the idea of building an electric jeep years ago. I have the schooling and the parts readily available for almost nothing. I determined that even for me it was a huge project and abandoned the idea.

 

[js5020]

I have given some thought to this idea myself, how big a machine are you thinking of converting? A major drawback with any electric vehicle is the costs involved in the conversion, new motors, controllers and batteries are expensive, basically all the expenses are "upfront" before the machine can be used. The big issue really is the battery,, or fuel, it's a major cost as your essentially buying 5 to 8 years of fuel upfront, not as you use it. Batteries get expensive, even a pack made of 4 six volt commercials for 24 volts is gonna run in the area of $400 or more and a charger will have to be added to that cost.

Run times for the equipment obviously will depend on power consumed, and unlike gas/diesel once the power in the battery is consumed ya can't just tip another can into the tank it will take some time to recharge. But you can get around this problem, the solution is easy,,, but involves more cost, have another pack of batteries and change the pack out. With enough battery packs and adequate charger capacity the machine could be run 24/7 if that was your goal.

Components can be expensive if purchased new or if you have some knowledge and adaptation skills cheap, there are many sources of cheap parts , depending on what your looking for of course. The system can be simple or complex, depending on your needs, and of course the more complex the more cost will be involved.

I'll have to find the links for some of the conversions that are out there on the web, they range from conversions to full scratch builds.

 

[jeff_jeff]

Here's a link to plans for an electrict gardern tractor - Its on my future projects list.

Home built (DIY) small electric buggies and go kart plans - DIY 1300 Watt Yard Tractor.

 

[Wayne County Hose]

Here's a link to plans for an electrict gardern tractor - Its on my future projects list.

Home built (DIY) small electric buggies and go kart plans - DIY 1300 Watt Yard Tractor.

That little thing isn't worth the scrap it's made out of.
First of all, the drive wheels have about 1.5 hp each after losses, it would barely climb a small grade.
Second, they have no provisions for turning. No, I don't mean the steering wheel. On a dual drive motor truck, you need to have provisions to slow down or stop the inside drive wheel when turning. Kind of like what spider gears do in a rear axle. This can be done with either limit switches on the steering or electrically thru the controller with a steering feedback sensor. And I could go on for pages.
Personally, I would have gone with a 36v controller. This way you keep the amps down prolonging the life of all the electrical components. If I were to build anything larger, it would be at least 72 volts. I would go with higher voltages except for lack of obtaining a controller. I know that 72v controllers are easily obtainable, I don't know about higher voltage.
If anyone is interested, some good motor controller companies are Curtis, General Electric, and a fairly new one on the scene is Danaher. The cheapest and most popular are the Curtis units. GE has gotten their butts kicked lately by the other 2. I've worked on some of Danaher's stuff, DC power converted to AC to power the motors. Their stuff is very reliable, but pricey too. Also, AC drive is the way to go. Most forklift manufacturers have converted over to AC drive and lift systems. Some Forklift manufacturers don't even make a DC motor anymore. I can set-up an AC powered forklift to smoke the drive tires. DC trucks could never do that. Pretty funny seeing an 8,000 lb. electric forklift smoking the tires.
Ugh, now you guys have me thinking about building an electric powered vehicle again.

 

[keeney]

I was noticing that many of the newer Zamboni units being put into service are electric. Being used almost exclusively indoors for 15 minutes every hour or so, they are a perfect applicaiton for electric power.

 

[Wayne County Hose]

I was noticing that many of the newer Zamboni units being put into service are electric. Being used almost exclusively indoors for 15 minutes every hour or so, they are a perfect applicaiton for electric power.

Actually, this is a very poor application for electric power. Battery powered vehicles are made to run the batteries down to 80% discharged, rested for 8 hours (theoretically, rarely happens in the real world) then charged to full capacity. Short term use, under 4 hours a day, hurts a battery more than running it to 80% discharged. Zambonies are probably electric powered because of the lawyers. A 40LB. propane tank and exhausting fumes from an IC engine in the middle of 8,000 people isn't the safest thing.

 

[js5020]

Here is a link to a neat machne, RENEWABLES.com : living without polluting. Same machine is on youtube as well.

 

[js5020]

Wayne, I have never heard nor seen any documentation from battery manufacturers on short term use of a battery hurting it, unless there was opportunity charging involved could you expound on that?

 

[Wayne County Hose]

Wayne, I have never heard nor seen any documentation from battery manufacturers on short term use of a battery hurting it, unless there was opportunity charging involved could you expound on that?

It's actually quite common knowledge that storing a battery in a state other than a full charge is not good for it's longevity. The lower the level of charge, the worse for the battery. It's not the short term use that hurts it, it's the static time between the uses. The battery being used and warming up, then being unused and cooling. It's these heating and cooling cycles that hurts the battery as much as anything. An industrial deep cycle battery is made to be discharged to 80% in one specific time period, that being about 6 full hours of run time, as clocked on the machines hour meter. This is true run time, not the operator sitting on the seat bs'ing with his buddy while the hour meter counts. For the Zamboni application, unless the battery was taken to 80% discharged then charged, the battery will never see it's full life potential.

There are many concrete undisputable things that will hurt a battery. There are certain applications, such as short term use, where the battery company tells you it will be okay for your battery. Battery companies will tell you it's okay for a lot of things because their competition will come in and say that their battery can handle it where the first guy said it's not good for the battery. Bingo, salesman #1 just lost a sale. You would be shocked to hear what battery salesmen have told me.

I have seen properly taken care of batteries last 9 years. I have seen batteries run short term (less than 3 hrs a day) and all else done by the book that didn't see 4 years. I have seen all the literature from the manufacturers and I have seen what works in the real world. If you notice, all industrial battery care sheets read almost word for word from one manufacturer to the next.


There is opportunity charging technology that does not harm the conventional deep cycle industrial battery. I didn't believe it until I saw it, but it works. The system zaps the battery for a short time at well over 400 amps. In a 15 minute break, this provides the battery with one heck of a charge.

js5020, I suspect from your question that you are involved somehow with something related to the field where large capacity electric batteries are in use. Care to elaborate?

 

[Wayne County Hose]

Here is a link to a neat machne, RENEWABLES.com : living without polluting. Same machine is on youtube as well.

I looked at this electric tractor and it is a joke at best. Did you know that an electric car puts more pollutants in the air than a modern comparable gasoline car? Yes, it's true. How does the battery car get it's energy, from the electric power lines, most of which are powered by coal. Oh, and last I knew coal was a fossil fuel just like gas. When a battery charges it emits hydrogen gas. How good is that for the atmosphere. Did you ever stick your face over a battery while it charges? I have. I'll take a bong hit from a tailpipe before a battery any day of the week. And what happens to the acid in a battery after it's useful life is up? You have to look at the big picture, not just tailpipe emissions.

As far as the solar goes on this tractor, how long do you really think those solar panels would last. If you say anything over a week, you are not being realistic.

Look, I'm not trying to start a peeing contest here. I'm just looking at the facts and the practicality. Back up the diesel tractor they show to their electric tractor and hook up a chain. And to claim that their tractor is "not polluting" is at best a false claim. There is no such thing as a free lunch.

 

[js5020]

Well now,,,,,,,,,,, I was just interested in your perception of the sulfation process, and the link to the tractor was just for the tractor, nothing else.

 

[6sunset6]

I had one of those GE lawn tractors a long time ago. 6 6v batteries I think.
It was great for mowing the lawn. Not great when I had to replace the batteries (don't remember how long). Sold it when I had to graduate to doing other things besides mowing the lawn. Todays batteries are better but still It does not feel right for tractor kinds of things

 

[Wayne County Hose]

I could definately see electric tractors in the future. The only thing holding them back is battery technology. When batteries can be made lighter and more powerful, and be able to charge them at any time throughout the discharge cycle, they will really take off.

 

[Wayne County Hose]

Wayne, I have never heard nor seen any documentation from battery manufacturers on short term use of a battery hurting it, unless there was opportunity charging involved could you expound on that?

Hey, come on now, I answered your question.

 

[js5020]

Hey Wayne, I just like to get others perspectives and/or knowledge on various subjects that interest me be it for work or play. Not trying to be an irritant or dispell anything you have posted.