Re: Grid-Battery "Hybrid" Tractors

't think that full-electric tractors are going to show up

That's why the grid-battery "hybrid" is the most cost effective solution

The tractor never goes very far and can work with a relatively small battery, a couple of Teslas would be more than enough.

The small cell phone or lap top batteries wired in parallel would charge up in a couple of minutes.

rs, and higher in efficiency than gasoline cars.

Diesel power is already 3X more than grid power and the spiraling is _not_ going to stop.

A few percentage points in efficiency over spark ignition will not save diesel.

high power; near the most efficient RPM possible).

They waste tons idling at the end of a field.

Even EVs don't get much either, maybe 20% efficiency.

s to provide high-power for an entire work-day out in the

Sounds like the perfect application for an electric moror.

To drain money out of the farmer's pocket.

back-of-the-envelope calculations, we need a 6-10X

n be matched with equal power and equal weight.

That's why the tractor is recharged each lap. It can get by with a relatively small battery.

Passenger vehicles don't have the option of getting recharged every 6

- 10 minutes.

The electric tractor is a much better application of batteries.

The driving range of a tractor is half a mile with the two wire system on a quarter square.

electric for a while.

A tractor would be easy to prototype.

It's not like retolling a production line for a Prius or Volt.

in diesel-electric locomotives) does save fuel, increases

The savings aren't significant.

I was planning for 6 - 10 an hour.

Every time the tractor makes it across the field or back it recharges.

Every time you decrease the time between charges you decrease battery cost and size.

Road vehicles do _not_ have this option.

X per work day.

Farmers find it acceptable to paying drivers $100 to sit at border crossings to buy diesel at $3/gallon.

Why not instead pay the tractor operator to sit at a line a couple of minutes after each pass?

Bret Cahill

Reply to
Bret Cahill
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Laptop batteries are typically good for about 1000 charges before becoming seriously degraded. Your hypothetical tractor would need a fresh set of batteries about every

2 weeks. You haven't taken this major cost into account.
Reply to
Mark Thorson

How would this cost be any different than the plug in hybrid or EV like the Tesla?

At least here the batteries are relatively small and replaced relatively often allowing for frequent upgrades.

I have yet to hear even one poster claim any knowledge of anyone in the battery industry or academia or any other authority who will not agree that battery technology is still improving fairly rapidly, energy density as well as recharge times.

Bret Cahill

Reply to
Bret Cahill

Because a car is only charged once or twice a day. If we assume an 8-hour shift, your tractor is being recharged 48-80 times a day. If this big, expensive tractor is used for multiple shifts, it could be much higher than that. You'll be producing mountains of dead, expensive batteries. There isn't enough hazmat landfill to handle them all.

Reply to
Mark Thorson

I like that idea a lot. Could maybe even have a separate battery 'wagon' that follows the tractor closely by itself (with a distance sensors and a small computer). The battery wagon can be plugged in an out very easily (without having to remove the battery from the tractor itself). Only problem might be that the mass of the tractor might no longer be enough for good traction. So maybe we should leave the old ICE in there :o)

Reply to
Rob Dekker

You throw a wire over it. Just make sure to wear rubber gloves :o)

Reply to
Rob Dekker

Please RECYCLE batteries. The metals in there are valuable (especially for lithium-based cells).

Although for tractors, you probably would not use Li-ions that are designed for small applications, although even these would already be economical (as Tesla shows). But for tractors, the low-cost, high energy density molten salt batteries (Zebra's, sodium/sulfur etc) are excellent :

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Cheap, powerfull, thousands of cycles, and easy to recycle. With their high operating temperatures, these are rather 'clumsy' for small applications. But for tractors, busses and anything big, they should be great.

Rob

Reply to
Rob Dekker

Tell us about your farming experience.

John

Reply to
John Larkin

Here, I'll try again:

How does this change the cost/number of cycles?

How does this change the cost/number of cycles?

And?

Again, why wouldn't this also apply to series hybrids like the Volt?

Bret Cahill

Reply to
Bret Cahill

Because the tremendous cost of the batteries must be factored into the cost. I have two dead batteries for my ThinkPad laptop, because I bought a spare for nearly $100. This laptop has not used anywhere near $100 worth of electricity, and the batteries didn't last long at all.

Because unlike a car, you are beating on the batteries at a far higher rate -- about two orders of magnitude higher. What is barely feasible for a car is obviously unfeasible for a tractor.

So instead of burning through a set of batteries in two weeks, it could be one week or less than one week. The cost of batteries would greatly exceed the cost of the vehicle or the cost of electricity. If the other killer arguments against your proposal were not sufficient, this one by itself is sufficient.

It does, but on a time-scale that is two orders of magnitude longer. Farmers aren't going to be spending tens of thousands of dollars every one or two weeks to replace batteries. Your proposal is an obvious non-starter. Calling people morons who point this out to you does not increase your credibility.

Reply to
Mark Thorson

Again, how does this change the cost/number of cycles?

=2E . .

Does the number of cycles/battery decrease with frequency?

Bret Cahill

Reply to
Bret Cahill

Well, I guess I won't be ever buying their batteries then.

Reply to
terryc

ROFL.

Reply to
terryc

Sigh. Basics of electrical pwer distribution; distrubte in as high a voltage as you can to reduce current being moved,then transform down for local requirements.> AFAIK, 11Kv is the next step up from 415V supply.

Reply to
terryc

Seriously, it isn't really ever an issue because oce you start looking at the alternatives, it just beats them hands down.

Now, at about $1,000/barrel, it might be a big issue.

Reply to
terryc

Oh, how do I find your figures?

Reply to
terryc

Huh, you want to encourage extreme peaks in demand for electricity?

There is, there is. I keep doing the figures on a battery car and every time, it is far cheaper to run a diesel car.

Reply to
terryc

Do you have any idea how much it will cost to put up that infrastructure and maintain it?

Crop farmers will just love that idea; massive bird perch for the seed eaters.

ROFPMP. You are just so hilarious. Have you done any maths on this matter?

Oh, do you know that all the existing fast charge batteries are liable to explode when fast charged?

Reply to
terryc

Yep, that would have just made my day, when I was ploughing; do a lap of the paddock, disconnect plough, drive over to recharge point, connect up, make a cuppa whilst it recharged, disconnect, drive back to plough, reconnect plow, do another lap and repeat.

Reply to
terryc

(Zebra's, sodium/sulfur etc) are excellent :

Low cost? I want a url to a price sheet. What is the energy density?

Reply to
terryc

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