Grid-Battery "Hybrid" Tractors

[Mark Thorson]

Bret Cahill wrote:

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

10 recharges during a work-day

I was planning for 6 - 10 an hour.

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

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.

 

[Bret Cahill]

If a battery with a capacity of 2 AH (120 ampere-minutes) needs to be
recharged in two minutes, then you've got to fill it back up with the
same amount of electricity, but you've only got 2 minutes to do it in,
so you've got to pump it in faster than it came out. ?

And it "came out" in 6 - 10 minutes.

The tractor is moving 6 - 10 mph.

---
So how long would you want to wait for the battery to charge up?

One minute? you'd still have to pump in at least 6 times as much
current as came out.

Which is trivial merely by wiring in more batteries in parallel.

Are you just acting dumb or are you really this stupid in real life?

.. . .

Alternatively, if the tractor is moving slowly, then it won't require
400 hp, and you'll _still_ have a short charging time.

You were the one who stipulated 400HP

The real savings appear in the energy intensive operations.

The more energy intensive the operation, the bigger the savings from
moving from diesel to batteries.

If you go to less energy intensive operations, say a garden tractor,
it is of course cheaper to go Li-Ion instead of liquid fuel, but the
absolute savings aren't all that great.

Are you just acting stupid or are you really a moron in real life?


Bret Cahill

 

[Bret Cahill]

Not that pausing a few minutes is a problem either but a fast
recharging battery just isn't a serious issue.

All that is necessary is make the cells smaller.

The smaller the cell, the faster the recharge.

This should be common knowledge.

Bret Cahill

Show us a link to a datasheet for such a battery.

Meanwhile, consider a AA size battery with, say, a 2 AH capacity.
Consider charging it in one minute.

See the problem?

No, at least nothing compared to the problem of paying $30 billion a
year -- soon to be $100 billion/yr -- for diesel used in agriculture.

Avoiding the issue by changing the subject, are we???

_You_ not "we."

The original issue was _always_ the $100 billion wasted on diesel.

But it's not the issue presently,

The cost of liquid fuel compared to grid-battery is the only reason to
discuss the electric tractor.

If you try to weasel out of the relative cost of diesel vs grid-
battery everyone will know you're a loser as well as a moron.

what is is whether you understand
the economics of battery charging. ďż˝

There is one reason and one reason only to discuss the cost of grid-
battery energy:

To compare it with diesel.

To win this debate you'll need to show how diesel power is cheaper
than charging batteries and running an electic motor off them.

You cannot so you will try to dodge the issue of diesel costs
altogether.


Bret Cahill

 

[Bret Cahill]

Not that pausing a few minutes is a problem either but a fast
recharging battery just isn't a serious issue.

All that is necessary is make the cells smaller.

The smaller the cell, the faster the recharge.

---
And the more expensive the finished battery cost per watt-hour.

Which is still a fraction of the cost of diesel at today's prices.

Next year batteries will be an even smaller fraction of the cost of
diesel.


Bret Cahill

 

[Bret Cahill]

There are dozens of farm service companies in agricultural areas
because the reality is no farmer needs the same equipment 24/7/52.

Lol, the problem with this idea is that farmers producing the same crop
generally all do the same job at the same time.

Another argument for grid battery tractors. For longer higher power
applications, all you really need to rent _or_ buy is another battery
in parallel.

There is just no situation where diesel is more cost effective than
grid battery.

Not in energy costs, not in labor costs, not in capital costs, not in
maintenance costs.


Bret Cahill

 

[Mark Thorson]

Bret Cahill wrote:

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

10 recharges during a work-day

I was planning for 6 - 10 an hour.

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

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.

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

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.

 

[Bret Cahill]

It's a whole lot cheaper to electrify, even if you have to buy 14,000
laptop batteries (twice that of the 200 kW Tesla) and install them
yourself.

Actually, your system might work better if the tractor camewith a pair of
swappable battery packs that you dock in and out of a charging station.

I mentioned that here last summer. It might take 2 - 3 dozen large
expensive battery packs.

But I don't deny even that might eventually be more cost effective
than diesel.

The cheapest fastest way to go now is the trolly wire - battery
"hybrid."

Batteries can be wired in parallel for fast recharging. So the guy
pauses a minute or so at the end of the field . . . no biggie. His
job is to make money and he can no longer make money burning 2-oil.

It would certainly help the economics by reducing the peak power demands.

If they are using lasers and GPS they can plow at night. TVA has 7 GW
available at 7 cents / kW hr. at night, about 1/4th the cost of diesel
power

The SW will soon have a lot of solar anyway.


Bret Cahill

 

[Bret Cahill]

Put out the shoe and the idiots step right in.

Not that pausing a few minutes is a problem either but a fast
recharging battery just isn't a serious issue.

All that is necessary is make the cells smaller.

The smaller the cell, the faster the recharge.

---
And the more expensive the finished battery cost per watt-hour.

The tractor only goes a mile between charges so a tractor battery
doesn't need a lot of watt-hours / work done.

---
Really?

Your 400 horsepower tractor, working for an hour, would need a battery
which can supply about 300KWH, (300 000 watt-hours) and if it's doing
it with an output voltage of 300V that means it needs to be rated for
an output of 1000AH at C/1.

That's a lot of watt-hours and a lot of work done.

True.

Not true.

The tractor only needs to make one "lap" between charges -- a few
minutes.

---
Did you miss the posts about when a tractor goes 0.5 MPH?

Did you miss the response?

That the more diesel the tractor burns the more cost effective it is
to switch to battery-grid electric tractors?

Are you just acting dumb or are you really this dumb in real life?


Bret Cahill

 

[Bret Cahill]

how much do they cost,

Whatever happened to rugged induhvidualism? ?Visitwww.homedepot.com
and look it up.

? ?Whatever happened to clear thought,

IWe're still waiting for some clear thinging on the fundamental
differences between plug in hybrids and grid-battery tractors.

Bret, I admire your out-of-the-box idea of battery-driven tractors, I don't think that full-electric tractors are going to show up
any time soon.

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.

Couple of differences with plug-in hybrid passenger vehicles come to mind :
- The use diesel, which has a higher value of combustion than gasoline cars, 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.

- They are (when working) operating at near-optimal efficiency (constant high power; near the most efficient RPM possible).

They waste tons idling at the end of a field.

- The don't gain much from regenerative breaking.

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

- Tractors are essentially a big engine on wheels. Their entire purpose is to provide high-power for an entire work-day out in the
field.

Sounds like the perfect application for an electric moror.

The diesel tank is configered accordingly.

To drain money out of the farmer's pocket.

Battery technology is not competitive with such modes of operation. In my back-of-the-envelope calculations, we need a 6-10X
improvement of battery energy density (w.r.t. Li-ion) before the range can 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.

Battery tech IS competitive for passenger vehicles,

Passenger vehicles don't have the option of getting recharged every 6
- 10 minutes.

The electric tractor is a much better application of batteries.

although even there we need to compromise on the driving range (hence PHEVs).

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

So
from all the vehicles around, tractors have a lower chance of going full-electric for a while.

A tractor would be easy to prototype.

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

Different story for electric-drive tractors. Electric-drive (such as used in diesel-electric locomotives) does save fuel, increases
torch, and simplifies operation.

Caterpillar has at least one of these fuel savers :http://www.heavyequipmentforums.com/Forum/showthread.php?t=5853

Smaller tractors (lawn-mowers and other etc) could actually go electric rather easily.

The savings aren't significant.

I already provided one difference: �The tractor battery only needs a
charge that will last a few minutes, an order of magnitude less time
than the hybrid.

True, if it needs to re-charge during the work day.

10 recharges during a work-day

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.

would compensate for the 10X difference in battery tech.
So your idea might work IF the farmer finds it acceptable to re-charge 10X 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

 

[Bret Cahill]

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

10 recharges during a work-day

I was planning for 6 - 10 an hour.

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

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.

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

 

[John Larkin]

On Thu, 24 Jul 2008 12:44:16 -0700 (PDT), BretCahill@peoplepc.com
wrote:

And we haven't gotten to the favorable torque/rpm curve of electric
motors which allows a much smaller hp motor.

Didn't somebody already invent gears?

You _want_ to go Rube Goldberg?

If your goal is to cost farmers more money then that explains a lot.


Bret Cahill

Tell us about your farming experience.

John

 

[John Larkin]

On Tue, 22 Jul 2008 07:35:57 -0700 (PDT), BretCahill@peoplepc.com
wrote:

On Jul 21, 10:45?pm, John Larkin
jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
On Mon, 21 Jul 2008 22:13:12 -0700 (PDT), Bret Cahill

BretCah...@aol.com> wrote:
Not that pausing a few minutes is a problem either but a fast
recharging battery just isn't a serious issue.

All that is necessary is make the cells smaller.

The smaller the cell, the faster the recharge.

This should be common knowledge.

Bret Cahill

Show us a link to a datasheet for such a battery.

Meanwhile, consider a AA size battery with, say, a 2 AH capacity.
Consider charging it in one minute.

See the problem?

No, at least nothing compared to the problem of paying $30 billion a
year -- soon to be $100 billion/yr -- for diesel used in agriculture.


Bret Cahill

Ah, the $100b is "soon to be." The number didn't make sense; in the
US, I figured farmers are currently running around $20b a year for
diesel. More is probably spent on transporting the products after they
leave the farm.

Crude oil is down to $124 today.

John

 

[Mark Thorson]

Bret Cahill wrote:

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

10 recharges during a work-day

I was planning for 6 - 10 an hour.

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

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.

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

Because a car is only charged once or twice a day.

Here, I'll try again:

How does this change the cost/number of cycles?

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.

If we assume an 8-hour shift, your tractor
is being recharged 48-80 times a day.

How does this change the cost/number of cycles?

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.

 If this
big, expensive tractor is used for multiple
shifts, it could be much higher than that.

And?

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.

You'll be producing mountains of dead, expensive
batteries. Â There isn't enough hazmat landfill
to handle them all.

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

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.

 

[Bret Cahill]

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

10 recharges during a work-day

I was planning for 6 - 10 an hour.

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

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.

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

Because a car is only charged once or twice a day.

Here, I'll try again:

How does this change the cost/number of cycles?

If we assume an 8-hour shift, your tractor
is being recharged 48-80 times a day.

How does this change the cost/number of cycles?

 If this
big, expensive tractor is used for multiple
shifts, it could be much higher than that.

And?

You'll be producing mountains of dead, expensive
batteries.  There isn't enough hazmat landfill
to handle them all.

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


Bret Cahill

 

[terryc]

On Thu, 24 Jul 2008 12:47:24 -0700, BretCahill wrote:

Still trying to dodge the OP issue, the cost of diesel fuel?

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.

 

[terryc]

On Thu, 24 Jul 2008 13:14:04 -0700, Bret Cahill wrote:

To win this debate you'll need to show how diesel power is cheaper
than charging batteries and running an electic motor off them.

Oh, how do I find your figures?

 

[terryc]

On Thu, 24 Jul 2008 13:22:36 -0700, Bret Cahill wrote:

There are dozens of farm service companies in agricultural areas
because the reality is no farmer needs the same equipment 24/7/52.

Lol, the problem with this idea is that farmers producing the same crop
generally all do the same job at the same time.

Another argument for grid battery tractors.

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

There is just no situation where diesel is more cost effective than grid
battery.

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.

 

[terryc]

On Thu, 24 Jul 2008 13:36:18 -0700, Bret Cahill wrote:

The cheapest fastest way to go now is the trolly wire - battery
"hybrid."

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.

Batteries can be wired in parallel for fast recharging. So the guy
pauses a minute or so at the end of the field . . . no biggie.

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?

 

[terryc]

On Thu, 24 Jul 2008 16:20:32 -0700, Rob Dekker wrote:

"terryc" <newssixspam-spam@woa.com.au> wrote in message newsan.2008.07.24.13.50.30.164653@woa.com.au...
On Tue, 22 Jul 2008 18:34:37 -0700, Rob Dekker wrote:

True. But technically speaking, a 300 kWh battery is not completely rediculous : It will cost about $100,000 wholesale, and weigh
less than 2 ton.

Well, that is an interesting battery advancement.

For current deep-discharge lead acid, it would weigh 84 tonnes.
In LiPoly,it would currently weigh 20 tonnes.



Did I make a calculation mistake ?
Mmm. Not really :

Li-poly gets us about 160 Wh/kg. That's less than 2 ton for 300 kWh.

You desperately need new batteries in your calculator.

300Kwh = 300,000 wh.

The only problem with this one (technically) is that it recharges up to 500x.

This is the whole point about why diesel has to rise another order of
magnitude before this idea even gets considerable.

 

[terryc]

On Thu, 24 Jul 2008 14:17:54 -0700, Bret Cahill wrote:

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

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.