# ev semi. no critisism just info please



## jackbauer (Jan 12, 2008)

Ok i'll jump in. First , the bad news.
A truck trailer rig is heavy. Either laden or unladen. Newton's first law tells us that when that truck is stopped , it want to stay stopped unless we push it hard enough. That means you need tons of torque and why trucks have 16 speed boxes (or more i'm not an expert). This resistance to motion will require a lot of electric power to overcome. 

Your next problem is when you get up any speed much above 30mph. You hit wind resistance. A truck is a brick wall to air. Worst case scenario.

Now for some good news. Forget about 10 motors. The controller would be a nightmare. Large enough DC motors exist today to suit your needs using only perhaps 2 or even 3. A managable figure. Just today I saw the largest forklift truck I have ever seen in my life. Its a beast. Weighs in at 26 tons and about 20 or more feet long. Guess what? its electric! Runs at 80v dc from a 2000ah lead acid battery which weighs 5 tons itself.

If you have a look in the motor forum under the forklift motor thread a few pages back , i got a picture of a drivetrain from a smaller version of this. 2 or 3 of those motors would get you moving.
http://www.diyelectriccar.com/forums/showpost.php?p=181049&postcount=1092

best of luck!


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## DavidDymaxion (Dec 1, 2008)

A couple of other things to consider:

How are you going to hook up 10 motors? If inline, the torques are going to add up and twist the shafts in half. If a parallel connection, space is going to be an issue. Maybe a long driveshaft would work with motors belted to it.

Something else to think about is can you charge this fast enough? A car takes roughly overnight on a 120V plug after 40 miles of driving. It would take around 500 (yes, five hundred) of these plugs to recharge a semi overnight. Even with 240 V 50 Amp it would take 75 plugs.

Back of the envelope sanity check on your math: The semi is about 30 times the weight of a car, and you want to go about 20 times as far as a 50 Ahr lead acid car conversion can go. That means you'd need roughly 30 * 20 * 50 Ahr = 30,000 Ahr -- that's about 10x your number.


Wickedtrucker said:


> ok here goes. i seen a couple shoot downs of semi ev's but no techinals on applications. what i am interested in is info on how many strings of cells and such. here is the run down. the class 8 truck would be a 2010 international 9400i Over the Road tractor. Weight of tractor is 19,000 lbs. dry weight. Trailer would be a Dane as they are fairly light at 15,000 lbs. with refer unit. gvw would have to hit 80,000 lbs with 90,000 lbs possible as new laws coming into effect could see that weight in near future. I was thinking just 1 motor hooked to a 8 or 9 speed transmission. or possibly using 10 warp 9's. Theory on 10 warp 9's would be that 1 motor wouldn't be enough but maybe possible to push pull 80,000 lbs with some efficiency. shouldn't need all 10 as that would produce more torque then would be required even going from a stop. I would look into hybrids but Honda beat me to it by creating several otr hybrids already. This is what I can tell you so far on the truck. engine bay would be roughly capable of holding 4 x 4 x 4 ft of space erm I think that is 64 cubic ft. fuel tank area is 2 x 2 x 8 or 32 cubic ft per side. also the 2 axles on the 10 warps at 250 to 500 lbs each would be removed as that system would be direct drive. There is also 1 x 5 x 8.5 or 42.5 cubic feet available behind sleeper of truck for batteries charging outlets and such. If I used a day cab setup i could put more weight and batteries in that area to the tune of 6 x 8 x 8.5 or 408 cubic feet plus the 42.5 cubic feet of batteries. The day cab weight could be brought down to 9,000 lbs dry weight with out conversion, for a conversion weight up to 24,000 lbs if needed. The trailer would lose about 500 lbs from the axles but that would brought back by using electric motors and installing a complete wrap around of solar panels for no reason but to help with charging or extending range ( even an extension of 1 mile per day would be worth the effort for theoretical purposes ). Now keep in mind cost is only an issue if the truck can not break even in 7. 5 to 10 years. This is the life of the average OTR truck anyway. A few people have posted on here asking these same questions but all I have seen as far as real data is nothing. Just critisism and no real info on what was asked for. So here is what I am looking for. Which motor or motors would work well. (theory). data on said motor(s). battery packs. cells per string. controllers and which recharger(s) would work. I can look costs up if I can get part numbers or actual controller and charger names. my very bad math says that I would need to generate something in the neighborhood of 2,250,000 kwh for 750 mile day. using 2.3 ah batteries. with 10 warp 9's it would come out to 21600 wh/mile and i would need 21600 kwh per day. i know my math is screwed up and was hoping for someone to help replan or re math my math. The batteries would need to come out to 2500 ah per day i think. i believe that is 100% dod use which is wrong. I need a recalculation of maybe 70% as the batteries would need to last 10 years if possible 7.5 years would be preferable as resale of truck should deffenitely be concidered. Sorry for long post as I feel all this info is very important to the over all theory of the project. I have been watching ev's for a couple years now and see we haven't really gotten anywhere yet but that could change in the next couple years drastically. Hoping for some serious data. and Thanks for any theories or designs info.


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## 2cycle (Jul 2, 2009)

If you plan on doing direct drive without using multi speeds through a gear box like the tractor originally has you better double up on those 9's, you likely will need about 20,000 lb/ft of torque available motor power if you want to achieve the same accel and speed as the OEM set up in high gear.


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## TX_Dj (Jul 25, 2008)

jackbauer said:


> That means you need tons of torque and why trucks have 16 speed boxes (or more i'm not an expert).


Well, not quite. Most trucks on the road use a 9, 10, or 13. Few trucks use less than 9 (there are a lot of 8's though) and few trucks use 15's or 18's unless they are commonly at max gross and cross mountains on most trips.

The torque comes from their gargantuan engines, some of which can belt out 2000 lb-feet torque!

Here's the issue as I see it.

1) Cost - Yes, new tractors cost a big penny. A significant portion of that cost includes the engine and transmission, APU if equipped, and so on. The bulk of it though is in the rolling stock and cab/amenities. An EV tractor would cost significantly more than an ICE tractor if the performance and range characteristics were the same.
2) Aerodynamics - Even the most aero cabs on the market today have pretty poor aero characteristics. Pete made a nice cab-over back in the 80's/90's (forget which exact model) which was very streamlined, and it got 11+ mpg at max gross! That's double what most large cars get, and even close to double what most modern aero conventionals gets.
3) Weight - Where are you going to stack all the weight of the components without tipping the scales too light or heavy on the steers and drives? Enough batteries to go the distance, using available lithium today, lets call out 260Ah Thunder Sky cells, using David's 30,000 Ah number, you'd need 116 cells just to get to 30,000 Ah at 3.2v. If you want decent performance, similar to what you'd get out of a big engine, you'll need something substantial, lets say 300v. So lets call that 94 cells in series just to make 300.8v nominal. So now you have a 94S116P pack of 260Ah cells, that's 10,904 cells.

Think about this for a second.

10,904 cells.
At 19.84 lbs each.
Where on earth on a road vehicle allowed to have 80,000 lbs or 90,000 lbs will you stuff 216,335.36 lbs of batteries?

10,904 cells.
At $316 each.
Who on earth is going to buy a road vehicle with $3,445,664 worth of batteries?


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## rillip3 (Jun 19, 2009)

For something this massive, you probably don't want DC. You'd have so much current coming in for all those motors you'd melt just about anything you tried to connect it with. AC would run a higher voltage, which would lower amperage and give you regen (without extra weight or cost), which might give you some decent power generation. But I don't know enough about AC to offer specifics. Almost all large applications like this are AC rather than DC though.


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## Wickedtrucker (Jul 28, 2010)

first thanks for some missing and inaccurate info i needed. I appreciate those numbers. At the very least they were entertaining while waiting for my truck to get loaded. I was at a shipper. Now i am broke down at a rest area from a flat tire.... owell life of a slave.... erm trucker. Anyway. some of your guy's numbers about trucks are off however. No current trucks run 16 speeds unless some guy special ordered it. they are 8 ( common ), 9 ( more common for fuel efficiency), 10's (cheaper and lighter then 13's), super 10's ( mostly ignorant companies buy these, and even dumber people drive them), 13's ( c.r. england favorite not bad but not super efficient either) 18's ( these are for the big boy toys 600 hp+ motors). My truck has only a 435 detroit with 600 lb's of torque. um were did you get the 2000 lbs of torque from???. even the 650 hp detroit in my bosses truck is only at 1750 lbs.... just for the record if you have anything above 550 hp in the truck you long sense gave up on fuel economy anyway. at that point it's all show and go! my truck with this crappy diesel we now have is getting 6.8 mpg at 80,000 lbs. my bosses truck gets 4 mpg. back in 03 when my truck was new it was common to see my truck get 7.2 mpg but not with this new crap they call diesel. And for the crappy pete you think is a truck. Well here's the skinny on your beloved pete. no one would drive it because it was a back breaker and butt ugly. areo? maybe then but now the newest trucks on the road will blow that pete away as far as areo dynamics go. you forget they changed diesel and emissions several times since that pete was made. and if you check the info on freightliner they can produce 11 mpg all day long on the new crappy diesel without being a crapover. but no one can afford the insurance. 

Brand new tractor from factory is roughly $105,000 without a discount or the owner operator flashy crap. standard 435 isx motor with 10 speed eaton fuller tranny. 2.66 rears 68" sleeper. white paint.
So for info I got 30,000 Ah at 3.2 v.
260 ah at 116 cells with 94 in each series? erm is this right?
or is it 94 series of 116 cells each?
These were lithium too you say? 
cost of batteries were 3.4 mil. Well will have to get that muslim socialist to help me pay for them. Grants anyone? did we forget that one?
weight is um yea well we'll just round off the the nearest 100,000 lbs with that one at 200,000 lbs...
the plan was 1 motor per wheel side as i believe with some work the could fit in between each wheel altho the drive axles would be tight. so having 10 wheel sides would mean 10 motors altho someone posted that wouldn't be needed. which would be a huge relief.
Now just need info on AC and how to tie solar into the system and I will have my 235,000 lb. Truck ready to haul freight.. Well I always wanted to be a heavy haul driver.... Hey theirs an idear. wind energy is heavy haul anyway! Again Big thank you. From the 18 wheeled side of life. Keep the shiny side up and the rubber side down, ya'll. Drive 'em safe.


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## IamIan (Mar 29, 2009)

I see needed torque as an issue , but one that was solved decades ago.

Electric Motors and Controllers that can handle The electric loads of fully loaded trains have been in service for decades ... which is far beyond the payload abilities needed here... some are ten times the power levels of this kind of truck.

So the question comes down to the batteries ... how much cranking power would it need ... how much range would it need ... how much space , weight and money $ would be needed to make that happen.

So for example a Mack Titan uses:
Peak of 605 HP ( ~451 kw )
Peak of 2,060 ft / lbs @ 1,200 RPMs

Without getting too much into technical ... Electric motors of equal power rating kick the snot out of any ICE in terms of torque... I've never seen an exception to this... and is one reason trains have been using electric motors as the prime mover for decades.

So we Need a Peak of ~450 kw.

If we used the A123 Prismatic 20Ah Cells:
~137 Wh / kg
~250 Wh / L
And If we pull them no harder than 10C discharge.

To meet our power needs we would need a minimum of ~45kwh.
~330 kg ( ~726 Lbs weight )
~180 L ( of space )

From here it is just a question of how much weight and space can you fit / afford ... in order to increase the range per charge.

- - - - - 

Of course ... if you filled an entire 80,000 Lbs trailer with these batteries....
You would have ~4.9 MWh of energy storage ... this would be enough energy to run a Mack Titan at full throttle ( max power ) for ~11 hours straight on one charge... and even 80,000 pounds does not need the Mack Titan's full ~450 kw power 100% of the time.

Now that is an EV with some range.


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## Wickedtrucker (Jul 28, 2010)

lol nice information there Iamian. Unfortunately the Mack Titan is a true heavy haul truck. that is why it has 4 axle's instead of 3 and has the big boy motor of 605 hp in it. the 51,000 lb Volvo A30E fully loaded with dirt, it's pulling should be a give away to another truck driver lol. For regular otr a motor of 450 to 480 hp is the ultimate effecient engine for the average steering wheel holder... erm truck driver. Not sure what 480 hp translates into for electric but i am sure it's some in kwh. ok the best possible empty weight of the truck would be somewhere in the area of maybe 28,000 lbs without the motor, tranny, and fuel tanks. could lighten it up some more by using aluminum frame and a daycab, to roughly 22,000 possibly 20,000 lbs. But I can't afford hotels every night. That would cost 700 bucks a week which is more then i make before taxes are taken out. I only really need to haul 40,000 lbs of freight as a rule but 44,000 lbs is normal in my truck and if I get a van trailer instead of a refer trailer I can hold 46,000 lbs which I usually do. I think i can hold about 7,000 to 16,000 lbs comfortably of batteries and motors and controllers on the truck. Depending on configuration used. Not sure how your math works out tho.


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## Duncan (Dec 8, 2008)

Hi Wicked

Just a few thoughts - I don't know how much power it takes to run a big rig but
You are talking 11mpg

The sort of cars that normally get converted get about 33mpg - call it 44mpg (diesel)
We normally talk about 200 - 300 watt hours per mile

So for your 11 mpg rig maybe 600 - 1200 wh/mile

That is pretty good considering that the rig is 20 times the weight!

You want 750 miles range

750 x 600 = 450,000 whrs or 450Kwhrs, 750 x 1200 = 900Kwhrs

(750 sounds high, at 60 mph that is 12.5 hrs driving - are you permitted to drive that long?)

A Thundersky 200Ah cell contains 200 x 3.2 = 640 watthrs and weighs 6kg
So a 450Kwhr battery will be about 700 cells and 4,218Kg - 9,300lbs
at a current cost of $220/cell it would cost $154,000 - I am sure you would get a good deal if buying that many cells

The 900Kwhr battery would be double

28,000lbs Truck + 9,300lbs battery + 2,000lbs motor and gearbox + 44,000lbs cargo = 83,000lbs - almost legal! - need to drop cargo to 41,000lbs to get under 80,000lbs

There are lots of motors that can do that sort of job - all of the big mining trucks are basically diesel electric.
I used to work on Cummins engines "3,500Hp at any altitude"
(78 liter V18 with 12 turbos!)
So even if the really big trucks use four motors (one for each wheel) one would do for your comparatively small rig 

As I see it the issue is cost, 
for the motors -unknown but probably (a lot) cheaper than a medium sized Cummins (N14, Signature-600)

The batteries however!!

You could look at Lead Acid,
The batteries would increase in weight by about three times- 9,300lbs would go to about 27,000lbs (and the 900Kwhr pack would be 54,000lbs)

28,000lbs truck + 27,000lbs batteries + 2,000lbs motor and gearbox = 57,000lbs 
leaving only 23,000lbs for cargo

Power requirements for acceleration

Assume a 320v system - with the Thundersky that would mean 7 strings in parallel (actually it would mean bigger cells do Thundersky do a 1400AH cell?)

at 2C that would give 2800Amps x 320v = 896Kw or 1200Hp *Should be enough*

As you would rarely (if ever) go up to 1C the Lead Acids would not degrade as much as in a car EV and would be about a quarter of the cost - $40,000?? 

Do these numbers make sense?


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## Wickedtrucker (Jul 28, 2010)

hi Duncan. Thanks for the info. you are correct that 750 miles would average 12.5 hours out east. however i run west were the speed limit is 75 and 80 even for big trucks. I can average 68 mph from des moines, IA to salt lake city utah and about 64 mph from slc to primm, nv. That is at 79,660 lbs. your numbers sound the most promising as they would still be doable and actually i could lower weight of cargo or see about getting lighter on the truck even or both. 35,000 lbs are quite common anyway. only loads that I really see pushing 40k+ lbs are steel and frozen food for the most part. atleast atm. I have also hualed plants and carpet at the 40k range. The nice thing about the cost of semi's versus cars is that the truck can make it's profit in years the cost savings of electric would add to that profit in the long run. That is why no one has tried it as of yet. still need those magic numbers to be on the black side. But if your numbers are correct then I can atleast look more seriously into converting a tractor trailer into electric. 3,000 lbs is really easy to shed. 200,000 lbs of batteries would be another lol. almost forgot. the cost of the whole setup could come to about 1.7 maybe 2 mil and in still be profitable enough to make it worth while, over the course of 7.5 years. 10 years i would have to take a guess at maybe 2.5 mil. even if for no other reason then just to say i did it first. lol.


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## Duncan (Dec 8, 2008)

Hi Wicked

If a truck can cost $1M and still make money then go to it!

Seriously you need to find

How much energy (Kwhrs) you need - my rough calculations show it is possible

I assume you have contacts in the trucking industry, 
When I was at Cummins they had data about energy requirements on various routes - it was being used to develop engine torque curves and to select gear ratios

You need that data to home in on your requirements

Motors
Cat and Komatsu both make mining trucks (400 tonne units)
I am pretty sure they are all diesel electric - you need to find out more about them 
I expect that they will be high voltage high frequency AC systems - probably one on each wheel

If I was in your position I would be trying to scrounge some bits off a dead mining truck

But then I am a cheap Scotsman!

The engines in those trucks are $250,000 or more, the trucks must be well over a million dollars

Did one of the posters mention a big forklift for a motor - or even a small train!

Passenger trains in the UK are 5 car units, four of the cars would have two Cummins N14's under the floor driving alternators
All five cars would have electric motors on the bogie's

They would do 150mph with an engine down 

The electric drives would have to be about 400Hp (each)


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## Wickedtrucker (Jul 28, 2010)

Well yea it can cost over a 1 million and still make money and here is why. I spend 430 to 475 dollars a day on fuel. I am on the road 350 days a year. I don't have a home of my own, I actually live in the truck. Sof take the minimum of 430 time 350 days and multiply. That is $150,000 a year that it costs me to fuel my truck... Well it costs the owner operator I work for anyway. Well now multiply that by 7 years and that is close to what the truck can cost and still make money. $1,053,500 in fuel alone over a 7 year period. Not to mention the $255 dollar oil changes I need every month and a half. That is another $2040 a year and over 7 years is $14280. I am not including the engine overhaul or anything else that accours during that same 7 years of course. But that is why the cost can be 1 million dollars and probably more.


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## jackbauer (Jan 12, 2008)

Thundersky make cells up to 7000ah so your covered there!
In fact they have a big luxury bus running on them.


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## aeroscott (Jan 5, 2008)

Duncan said:


> Hi Wicked
> 
> Just a few thoughts - I don't know how much power it takes to run a big rig but
> You are talking 11mpg
> ...


 We talked over this a month or 2 ago , I worked with 7mpg and 10kwh/gallon of diesel (output power) . the big truck pays the least penalty for weight/aero of any rubber tired vehicle on the road. prof, 7mpg for 80k lbs . Good work Duncan .


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## IamIan (Mar 29, 2009)

Wickedtrucker said:


> lol nice information there Iamian. Unfortunately the Mack Titan is a true heavy haul truck.
> 
> For regular otr a motor of 450 to 480 hp is the ultimate effecient engine for the average steering wheel holder... erm truck driver. Not sure what 480 hp translates into for electric but i am sure it's some in kwh.
> 
> I think i can hold about 7,000 to 16,000 lbs comfortably of batteries and motors and controllers on the truck. Depending on configuration used. Not sure how your math works out tho.


Less Peak Power just makes it easier 

I don't have specs on motor and controller weights at that scale ... but I know they are being used every day in small trains and large forklifts ... and have been for decades ... finding a good deal on a good match might be a good place to start.

If you only need a Peak power of ~480 HP ... that means you will only need a peak kW electric motor about ~360 kW peak ( maximum )

Lead is the cheapest kwh per $ ... but gives you the least kwh per lbs.
Translation: Lead is the cheapest to get a working vehicle ... but gives you the smallest range ( for a given amount of weight ) ... if that range is good enough for your needs ... than there is nothing wrong with using lead acid batteries.

Li options like the A123 cell I first referenced is at the other end ... cost allot $ per kwh ... but giving you the most kwh per lbs... so going that route would cost allot more ... but would give allot more range out of the same weight.

You have a better feel than I do how hard you are pushing the engine ... or how close you run to the max HP ( full throttle ) ... to travel for 1 hour if you spent 100% of the time at the peak of ~480 HP or ~360 kw ... You would need ~360 kwh of usable battery storage.... If you average more like ~50% of the engines max power ( ~180 kw or ~240 HP ) you would need about ~180kwh of usable battery storage... I'm not a truck driver but I would assume the average is allot less than the maximum peak full throttle level.

Lead Acid runs around 40 to 50 wh per kg.... or ~88 to ~110 wh / lb
So for ~180 kwh from lead Acid you would need about ~1,700 to ~2,100 Lbs of Lead Acid batteries per 1 Hour ... if during that hour you averaged using only about 1/2 of the total peak engine full throttle power... or ~240 HP or ~180 kw... if you ran 100% full throttle 100% of the time for the whole hour you would need ~3,400 to ~4,200 Lbs of Lead Acid batteries to give you the energy you would need for each 1 hour.

Although much more expensive ... the higher energy density of the Li options like the A123 20Ah parismatic cells which give you ~137 Wh / kg or ~301 Wh /lbs ... would about you to get much more range out of the same weight ... but at allot more cost in $... The same 1 hour at ~240 HP or ~180 kw would only need about ~600 Lbs of A123 Cells per hour of run time ... the 100% full throttle 100% of the time for the same hour would need ~1,200 lbs of the A123 Cells per hour of run time.

Sourcing the needed motor , controller etc , is also important part of it ... Just for a moment let's look just toward the batteries.

Given your available weight expectations of ~7,000 to ~16,000 pounds ...

At an average of ~240 HP or ~180 kw being used ... 

Lead Acid would give you a maximum range of about 2 to 4 hours Run Time at that average of ~240 HP or ~180 kw.

In the same expected weight the A123 Li batteries would give you a maximum range of about 5 to 12 hours Run Time at the average of ~240 HP or ~180 kw.

As an Average that does allow for peak periods of the full ~480 HP or ~360 kw ... but will be balanced by other times when you are using even less ... so it is if the average is only using about 1/2 the maximum full throttle power of the engine.

Of course cost can also be a major determining factor ... this will be a very very expensive project for up front initial expense.

There are allot of people on this site , many who know far more than I do ... who are happy to help ... best of luck.


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## Duncan (Dec 8, 2008)

Hi Wicked

Another thought - where do you park at night? 
you will need a fair amout of electricity to re-charge while you sleep

450KwHr - will be 60Kw for 8 hours
the 900Kwhr would be 120Kw for 8 hours

I believe a normal household supply is around 20Kw

You will need an industrial power supply at your overnight stop
just about any medium sized industrial unit will have more than enough capacity but you may need a heavy duty connector - three phase 100Amp - three phase 200Amp 

Night rate electricity is normally cheap - I pay $0.09/Kwhr
so a nightly charge would be 450Kwhrs x $0.09 = $40.50 - there will be some inefficiencies that will take it up to about $50 for the 450Kwhr pack and $100 for the 900Kwhr pack


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## Wickedtrucker (Jul 28, 2010)

Hehe well can't park at home anyway. The cops don't like my truck on the street. Their $65 parking tickets told me so. I would have to rent a place to park a truck but if I actually did this project I would have to rent a place to build the truck anyway. Need an inside overhead crane just to remove the engine and tranny. A thought just acurred to me. If I would need about 7800 lbs of Lithium battery to go 5 to 12 hours then maybe I would go ahead and fill up to the 16,000 lbs with Lithium batteries or at the very least to have that amount ready just in case. While Wisconsin and Illinois are both fairly flat. Out west it is seriously mountainous. Just go done going up a 6% grade at 30 mph that was 12 miles long. Sheesh that took forever. However only took about 10 minutes to go back down the otherside. It was in Utah and the speed limit was 80 mph all the way. Was fun blowing by the cops at 83 mph and not seeing the flashy disco's. The major hurdle of this whole theoretical project tho, is supply of electricity. As idleair went out of business last year and they could have setup their stalls to recharge the truck. I am certain it wouldn't have taken that much extra work to do, conscidering what they were spending on each truckstop anyway. Alas, will have to wait to see if they re-emerge again. At their peak they had like 120 locations with over 5000 stalls for electricity, cable, high speed internet, heat, and a/c units available for trucks. They were ahead of their time unfortunately. As you can see Trucks should have been high on the list for government funding to convert into ev's. At 145 gallons a day x 350 days for just one truck is 50,750 gallons of diesel a year. Their are 3.5 million trucks on the road and when the economy picks up that number could very well double or triple. I have seen in the last 4 years 300,000 to 500,000 truckers lose jobs because of the economy.


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## TX_Dj (Jul 25, 2008)

Well, I'll try not to take your comments directed at my information personally, though they were fairly well charged...

No, I don't drive trucks for a living, but I've been interested in trucks for 30+ years (most of my life).  My comments of on the number of gear ratios was simplified, for the benefit of others who don't know as much about the topic as you do, but it seems you took those comments as an attempt to educate you on your own livelihood, which it was not.

Anyhow, I think Duncan' 600-1200W/h mile figures are significantly under-estimated. My S10 pickup is estimated to require 500W/h mile when finished, with a gross curb weight of just under 5000 lbs. Just scaling that up by a factor of 16 to get to 80,000 lbs, we're talking 8000W/h mile, but that will vary greatly depending on how hard you are on the hammer.

Yes, COE's are a back breaker, yeah, it was butt ugly. These are great reasons why we don't see that old pete. Never said it was my favorite, just threw it out as an example.

As for the 2000 torque number I threw out, I took a big number and rounded up for simplicity. 500HP @ 1500 rpm = 1750 lb-ft. What's another 250 lbs between torque fans? MORE FUN! 

I think a key factor of my suspicion of Duncan's numbers is that they seem to stem from an "all things being equal" point of view of a 2500 lbs 30+ mpg vehicle's requirements, vs. an 80,000 lbs ~7 mpg vehicle. All things aren't equal, because if that 80,000 lbs vehicle had a gas engine it would be rated in gallons per mile.

The key thing to remember while you plan this idea is that torque won't be hard to find in the electric. You'll probably need even more of it than the diesel provides, because you'll get less HP from most electric setups. I *think* you dropped a 1 from your torque number on your engine, because 600 ft-lbs and 435 HP from a low-revving diesel doesn't make any sense. If your peak torque comes on at 1200, then you're only seeing 137 HP there. If your peak HP comes on at 1600, then you're seeing 1427 there, which is higher than the "peak torque". However, 1600 lb-ft at 1200 makes a lot more sense because that's 365 HP, and the torque will be less at the peak HP number.

You can make that kind of torque with a big enough electric, enough amps between the motor and controller, and a big enough pack voltage to control the sag that will happen when feeding the controller.

The big problem is still battery capacity. If we take my earlier "size up" and then scale it down to even 3000 wh/mi, you're looking at 2250kWh to make a 750 mile trip at that average. If you have 300v pack, you're still looking at over 7500 Ah usable capacity to 70-80 % DoD, so we're back to rounding that up to 10,000 just to be safe.

The 260Ah batts I used in my example before would then need about 38 parallel by 94 series to come out to a 10,000 Ah 300v pack, 3572 cells, times a rough rounding of 19 lbs per cell is 67,868 lbs just for the battery pack.

*shrug*


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## IamIan (Mar 29, 2009)

Wickedtrucker said:


> If I would need about 7800 lbs of Lithium battery to go 5 to 12 hours then maybe I would go ahead and fill up to the 16,000 lbs with Lithium batteries or at the very least to have that amount ready just in case.


Remember at this point we are doing lots of estimating ... as we don't have an Real world EV rig to quantify our numbers.

The 5 to 12 hour estimate was based on an average of ~240 HP or ~180 kw as an average power rate ... of course depending on how you drive and the road conditions ( uphill vs down hill ) your distance may vary... thus the 5 to 12 hour number.

I was also not assuming all 16,000 pounds would be batteries ... I thought that 16,000 pounds was the maximum you thought you would have for all components ... I was estimating ~10,000 pounds of good quality ~300 wh / lb Lithium batteries and the rest for all the other components and pieces you would need to make it work.



Wickedtrucker said:


> The major hurdle of this whole theoretical project tho, is supply of electricity.


100% agree... or more specifically access to supply ... as there is plentiful supply of electricity is distributed all over the country.

I work in a Carpentry shop that uses on average about ~600kw of power for the working hours of the day... sometimes more , sometimes less... but ~600kw is the average.

The lines that feed this supply could recharge your whole battery from 0% to 100% in just a few hours... so the supply is there ... And there are dozens of other industrial companies in the industrial park where I work... but access to this supply is restricted.

I think this access issue will be your #1 issue ... unless you do local routes , where you can return back to your own base station charging station each night.


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## Duncan (Dec 8, 2008)

Hi Tx

We need some actual experience - it would be good if wicked does get his truck so that we would have measurements of power used

In defense of my argument - the fuel used is a measure of the energy consumed - 
11 mpg diesel is not equal to 11 mpg petrol
diesel has 20% more energy and a diesel engine is a bit 15%?? more efficient
This gives a 38% advantage

Diesel cars do give better fuel mileage - but not 38%!!

In my calculation I increased the mileage for the 200-300wh/mile electric car from 33mpg to 44mpg to allow for this.

For a big truck I kind of assumed an AC system with re-gen that would help on some routes

The low power to weight ratio on the truck means the battery should be able to cope with the re-gen 

Overall I think if a diesel truck gets 11 mpg on a route then I would still expect an electric equivalent to use 600 - 1200whrs/mile 

Until fairly recently (60's) the USA used petrol engined trucks - the diesels did take over but even then the petrol units were not gallons to the mile


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## aeroscott (Jan 5, 2008)

check out posts in " All EV Conversions and builds "thread under, heavy truck application from may to june 2010 . some links on a heavy truck being built for L.A. port . On the gas to diesel thing , well the new diesel has much less energy then the old high sulfur diesel . From DOE , diesel 1,058,000 btu/cu ft , gasoline 950,000 btu/cu ft (about 8 gallons/cu ft). everything I drive and generate electricity with is diesel , except a 58,000 lb truck crane 6x6 with 560 cu. in. gas engine gets about 4 mpg @45mph maxed out @3300 rpm .Duncan your close .


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## aeroscott (Jan 5, 2008)

1058000 btu / 7.48 (gal/cu ft)=141,443 btu/ gallon diesel divide this by 3.4 (for3.4 btu= 1 watt hr.) 41,600 watts / gallon before it goes into the engine . ask any trucker if he gets fuel with this high energy content ,he will say no way . I bet this is a old diesel or off road high sulfur spec. ok so 41,600 watts x 33% =13728 watt hrs out put per gallon of very high spec. fuel under perfect running conditions . 13,728/748 (watts/hp.)=18.35 hp/gallon . 7mpg @70mph =10 gal./hr or 183 hp . diesel engine specifications use a lbs. of fuel per 1 hp. hr. of .33 lbs to .375 lbs , if diesel weighs 7 lbs divided by .33 lbs.= 21hp /gallon , 7 divided by.375= 18.66 hp per gallon . just found a site that put diesel weight 9.4 lbs/gallon heavyer then water , and another said 129,500 btu/gallon diesel this sounds right .


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## Wickedtrucker (Jul 28, 2010)

Iamian. yep I forgot about motors and controllers and such. Was just thinking batteries. Well I seen a single motor or a couple of them that are ac I believe could run the truck but I would have to use my tranny with them. So no direct drive on it. http://www.baldor.com/products/deta...ncy&hp=400&winding=18WGW344&rating=40CMB-CONT is the biggest of the motors and it would power the truck. But it doesn't say if it can regen on a downhill or in a costing situation. I can coast without slowing down quite a ways but probably not very long with regen engaged. But this electric motor was rated at 95.4% effecient. but ouch almost 3500 lbs. and of course multiple smaller motors seemed to be more weight together. I remember about 3 or 4 years ago, maybe longer, seeing a ford escort converted into electric and checked on a motor like this same one then. Not nearly as efficient and I couldn't even begin to figure out how many batteries then it would have taken. But idleair was available and it was expanding with possible 220v access coming at the time. Well that's all changed. I realised early that I would have to be able to return to my own shop to recharge as nothing comes even close to being able to charge a truck in 10 hours let alone in just a couple hours. And if I did go that route I would have a wind energies and solar system as being hooked into grid would be too much drain even for a small industrial shop. I am still confused on some of the batteries tho I seen thunder sky's 700 ah 2 v which I thought I needed 156 per string but couldn't figure out how many strings as I am not a math wiz. I also saw they made a 9000 ah 2v battery and a 7000 ah battery as well. there is another company out that makes 11,000 ah batteries but now I forgot which company that was. Anyway still dreaming the dream and all. Thanks to everyone for atleast lending to my theory. I also did check into grants to help but I am not an auto or truck manufacturer which I didn't realize you needed to be. bugger. figures everything is for big business and nothing for small business, as usual. Now if I could just win the lottery say the 150 mil+ one I could just build it for no other reason but to say hey look what I did. lol wonder if that virgin ceo dude would help lol.


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## aeroscott (Jan 5, 2008)

that motor is rated for 60hz at1800 rpm .the australians have tested standard industrail motors to 10 times the rated power with a volts/hz that works like this, as the hz and speed is increased more voltage is added ,every time the hz goes up so does the voltage . motors drop in torque as speed is increased ,normally. this is because as the motor turns faster it starts making its own voltage called back emf (electro motive force) this is reducing voltage that we want in the motor . the motor has a resistance (ohms) , this holds back the amps (torque),to get past the ohms we need voltage . as voltage drops( as speed going up, because back emf )so do the amps and torque drop, losing more torque the faster we turn our motor . the fix is adding more voltage as the speed increases to fight back emf .they used 1/3 hp 3 phase to 4 hp if I remember , with less heat at this high hz , high volts and high rpm . that's less heat then running at 1/3 hp . this is the big secret of aircraft electrics and other high performance motors . the motors need thin laminations for the high hz ,but this is done on the high efficiency motors anyway.so that $50,000 motor could power a train . but then it would cost $500,000 and have better bearing , a cool paint job some stanles steel cooling lines.


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## aeroscott (Jan 5, 2008)

the cat engine and trans weights about 6,000 lbs. if replaced with a 75 hp that weighs 1100 lbs , I figured about 1hp/1lb that's common in ev ac drives . you save near 5000 lbs to offset batteries .


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## Duncan (Dec 8, 2008)

Hi Wicked & Aeroscott

That motor is rated 400Hp at 60Hz and std 3phase (415v?)
- I think a smaller one would do at higher frequency and voltage 
but I think you would need to retain the gearbox although less speeds would be required


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## IamIan (Mar 29, 2009)

Wickedtrucker said:


> Iamian. yep I forgot about motors and controllers and such. Was just thinking batteries.


Batteries a a very big part of it ... no doubt... the 'heart' of it for allot of people... and setups.



Wickedtrucker said:


> Well I seen a single motor or a couple of them that are ac I believe could run the truck but I would have to use my tranny with them. So no direct drive on it. http://www.baldor.com/products/detail.asp?1=1&page=1&catalogonly=1&catalog=ECP44404T-4&product=AC+Motors&family=Premium+Efficiency|vw_ACMotors_PremiumEfficiency&hp=400&winding=18WGW344&rating=40CMB-CONT is the biggest of the motors and it would power the truck.


While that is a nice big motor ... it might be more powerful than you need.

That one is being listed as rated 400 HP on a continuous duty cycle.
Your trucks Peak ( or Maximum ) was something like ~480 HP.

There is a difference between the continuous power rating and the peak / maximum power rating... peaks and maximums can not be used continuously , but they are always significantly higher than the continuous rating.



Wickedtrucker said:


> But it doesn't say if it can regen on a downhill or in a costing situation. I can coast without slowing down quite a ways but probably not very long with regen engaged.


Coasting is always more efficient than regen when it is safe to do so.

You will always be less than 100% efficient ... so it is always most efficient to conserve energy in one form than to convert it when you can ... to do regen some would be lost converting mechanical to electrical , some of that would be lost converting electrical to chemical ( Into battery ) , some of that would be lost converting chemical to electrical ( out of Battery ) , some of that would be lost converting electrical back to mechanical.

So when you can do so safely ... coasting is always more efficient.

Now if you have to use brakes ... friction brakes throw away 100% of the braking energy ... so regenerative brakes are always more efficient than friction brakes ... when you have to brake.

One benefit of keeping a transmission instead of going direct drive ... Neutral.

You can coast in neutral without spending energy like you would have to in a direct drive system.

Although there are pros and cons in both methods ... I would recommend keeping a transmission ... You know the peak output power rating of the OEM motor ... the torque needed at certain RPMs and such ... you can monitor your engine usage to try and determine how often you use that 100% full power Max peak of ~480 HP ... and you can try to determine your average load on the engine you already have with a transmission ... without a transmission you won't have gearing to help you ... That means you will need different motor output numbers in order to have the same performance ... yes it can be done ... and there can be benefits to doing so ... but I think the project already has enough unknowns and potential issues to deal with ... I would not add one more without a good strong reason to do so.



Wickedtrucker said:


> I realised early that I would have to be able to return to my own shop to recharge as nothing comes even close to being able to charge a truck in 10 hours let alone in just a couple hours. And if I did go that route I would have a wind energies and solar system as being hooked into grid would be too much drain even for a small industrial shop.


If you can return to your own 'base' for recharging ... that effectively deals with access to electric supply.

When you look for a place to do this and to park the truck and such ... available electric service will be a very important question to ask ... but if you are in an industrial area , there is a good chance you can get access to 500+ kw service ... Like I said where I work uses more than that... at that level you would have little difficulty charging back up in a reasonable amount of time.



Wickedtrucker said:


> I am still confused on some of the batteries tho I seen thunder sky's 700 ah 2 v which I thought I needed 156 per string but couldn't figure out how many strings as I am not a math wiz.


You can spend the rest of your life learning about batteries ... if you have that interest great ... if not ... you can get some basic knowledge and work from there.

I would start off with your peak / max load needs ... you want a peak power roughly equal to the peak max power you have now ... ~400 HP peak is about ~300 kw.

Nominal cell voltage times peak discharge Amp rate = Peak kw power.
~300 kw from ~300 V is about ~1,000 Amps... 
you can get the same ~300 kw from ~1,000 V and ~300 Amps.

You can combine your battery cells in a number of ways.
Nominal 2V 700Ah cells 
10 of them connected in series adds voltage not Amps ( and Ah ).
So you end up with 20V 700Ah from 10 such cells in series.
10 of them in parallel adds current ( and Ah ) but not Voltage.
So you end up with 2V 7,000 Ah from 10 such cell in parallel.

Because the battery pack can be arranged around your voltage and current needs of the motor controller and motor itself ... I would suggest starting with sourcing a motor and controller that you would be happy with for performance and such.

So once you iron out the peak power needs , and you find source a motor and controller that you are happy with ... source the batteries you will need to be happy with.

I would recommend starting off in the battery research figuring your max / peak needs ... you're around ~300 kw ... how you want to divide that between Voltage and Amp current to make the motor and controller happy.

Then source the battery combination that will give you the results you want... make sure to include a buffer in the work ... if you think you will 
want to use ~300 kw ... planning for ~350 kw or so might be a good idea.

Now keep in mind the that if you use the whole Ah rating in 1 hour ... you're out of juice in ~1 Hour... That is when the 'C' battery rating comes in.

1C = Rated Ah used in 1 hour.
10C = Rated Ah used in 6 minutes
C/10 = Rated Ah used in 10 hours.


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## piotrsko (Dec 9, 2007)

anybody aware what siemens and mercedes are doing with their medium range EV delivery trucks?


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## jexter (Jul 13, 2010)

Really interesting discussion! It seems one of the problems with this type of conversion is that while automobiles have been improving in terms of wind resistance over the years, the basic design of tractors and trailers hasn't changed much from the time when fuel costs were almost negligible. 

But outside of designing a giant aerodynamic Prius-shaped EV long-haul carrier, or doing a straight EV conversion of a conventional tractor, how about some form of hybrid?

Battery capacity for small range of 20-30 miles, keeping the weight and cost of the conversion way down; small efficient diesel generator to keep the batteries topped up going up hills and on flat stretches, regenerative breaking topping up batteries on the downhills; option to plug in at home or the truck stop.

Does this make _any _sense?


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## Duncan (Dec 8, 2008)

Hi jexter

that makes sense but you missed the real big advantage - pollution is area specific some areas have weather systems that concentrate air pollution 
(I think LA,??)

A truck could use its diesels on the long haul where the area is not pollution sensitive and go to electric mode in the towns where every extra gram of NOX is a problem


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## Wickedtrucker (Jul 28, 2010)

hiya Jexter. The Hybrid class 8 (largest highway trucks in north america), has already been done by Honda in November of 2009. I haven't heard much about the truck other then it runs from georgia to south carolina somewhere. Honda has plans of putting more hybrid class 8's on the road soon as well. I was thinking of a hybrid first as well. But either of these concepts are super expensive for a single owner operator to convert to. Mostly I was just looking into this as a theory I really didn't expect to actually be within reach of the full EV conversion altho it is looking more like we are there or very very close. Hybrids are already here which means ev's are very close to follow. Unfortunately most trucking company's that are otr just don't have the extra funds to convert these trucks as freight prices are about 1/3 what they were 30 to 45 years ago. When i first started over 14 years ago you seen 2.00 to 3.00 a mile loads all the time. But now that is a thing of the past. Even the heavy haul and ice road pays have dramatically come down. my current job pays less then $8.00 / hr if you broke it down to a 70 hour week pay. Were 14 years ago I would scoff at a job that paid less the $15 per average hour worked. or roughly 37 cents per mile. This is the problem with deregulation and Brokerage firms double and triple booking loads.


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## Tronthor (Aug 2, 2010)

Hello Everyone,

This topic is so interesting that I had to register just to able to join in. It caught my eye because I own a 1984 "Class A" RV with a chevy 454 and 3speed transmission, and I've been so convinced that I can convert it that I actually started to do some math this past weekend....after 6 years, I figure I had better get to getting to it.

Anyway....

Wicked, I agree with you. EV or 90% or whatever it takes is the way to go. I work for a municipality in the IT dept., and see all sorts of things that could be done either hybrid or full EV that it blows my mind. The Trash and Recycling collection trucks - with full regen system - are a perfect match for either full EV or really efficient hybrid.

It sounds like you spend a lot of time going farther than half a day from your shop, so you have to consider the recharge.

Along the lines of Jexter's comments, I'd like to add to this and get feed back.

Sterling Engines.

What I'm not hearing is any discussion of capturing and returning any of the losses (in the form of heat) from the drive system in any way. This is free energy that you have already put into the system and are just throwing away. Regenerative breaking, unless Honda has a system for those Class 8 trucks already designed and tested, is not something that I'd want to play around with. I don't drive trucks, but I did start out in engineering, and I have a pilot's license - energy and what it does and can do is not to be trifled with. 80,000 lbs going 75-80mph ... let's just not go there. When it's got to stop, it's got to stop.

Back to my topic.

A Sterling Engine is a heat engine where the heat comes from outside - it runs on the sterling cycle (wikipedia has great info if you need to look it up) The potential is there. Here is a grid capable system designed with a solar concentrator to use the sun to power the engine - which drives a generator.

http://www.tesserasolar.com/north-america/technology.htm

The beauty is that you don't need a solar concentrator, you need a heat source and a cold source. The batteries, motor controller, the motor (certainly at these potentials), the transmission - you have to keep one in the system. The loads you are talking about and the variability of the terrain demand it. Unless you want to put in a motor that is way overboard for most of your run, and still perhaps not enough for that long grade that you ran @ 30 mph for 12miles - what was the altitude difference? the grade of the climb? we can calculate just the change in potential energy that you had to put into the rig by moving it up and the rate at which you did it, is a pure WORK (power/time) equation. And since we are talking about an OTR truck here, we are talking about sustained power output with only variable being the power that is output at any given moment. The transmission will let you easily do what we pilots pay very careful attention to - the energy bucket: you can trade speed for altitude, and altitude for speed at any time - so long as you have an excess of one when you need the other (if you don't then you crash - read the news, it happens). With the transmission you can keep everything happening in the happy range (max efficiency = max range on given charge) with the only sacrifice being the speed you do it at - even your big Detroit ICE was forced down to 30 mph for that grade. Electric motors are not going to suddenly allow you to not slow down - unless you have a huge motor and huge energy source to feed it....then again, you could have one of those really big monsters under the hood now and just go over that hill like no one's business. There are always going to be compromises.

However, getting back to the Stirling Engine turning a generator and your setup, there will always be ways to find heat - those friction brakes make heat very well - an add-on system to remove that heat without interfering with the normal operation of that system will do 2 things for you:
1) recover some of that energy you are otherwise throwing away - after you got it there in the first place without compromising the safety factor which is 1000% important.
2) increase both the efficiency and reliability of those old pad burners while decreasing the maintenance cost/cycle. Why can't you just stand on them going down those same grades? Simple, they heat up, stop working, (possibly destroying themselves) and cost a lot to replace - you simple flip that switch and get Ol' Jake to put in some OT along with that transmission you are dragging around.

The last item is a question: You stated eraly on about wrapping the trailer in solar cells. This brings us back to the Sterling Engine - it's more efficient than a lot of solar cells. If the trailer is to be considered an integral part of the system, then you can count the roof and side surface area as heat collectors. You could fashion linear solar concentrators even if you wanted to while staying within the DOT regs of size, shape, and protrusions for the box.

Add to the Sterling Engine, the absorption cycle cooling - very well worked out and used in industry a lot - and you can keep that refer cold as well as improve the output of your Sterling Engine + generator.

What does this mean? Well, given that we can safely figure out how much heat the operation of the controllers and discharging/recharging of the batteries will likely produce, we can determine a minimum output for a Sterling Engine+generator. This means that you can reduce both the cost and the weight of the batteries that you are considering. Also, you have a system which will work to recharge your batteries / keep the refer cool even on that 1 day a week you are not driving, or, if you are in a traffic situation, you might actually come out ahead (if you are sitting, or moving very slowly - electric drive can move very slowly very well and very controllably thus keeping your momentum from reaching zero and eliminating that need for the huge drain to overcome inertia of zero velocity. Even if you are only moving at .1 mph, you are in fact moving. That works out to 0.14666666666666666666667 feet per second. Not much, but figure that at 80,000 lbs, and you can see that he saves a huge amount of energy when the light turns green or the traffic moves, and since he can be sure of moving only that fast, it's about 5 feet in the course of a traffic light...between not quite stopping and beginning to move again - a trick that truckers and drivers who hate stop and go traffic have mastered - we change a lot of the equations we are working with here.

Anyway, the Sterling engine as a recovery (not regen because you don't actively drive it, it runs on what is otherwise waste heat energy) is a big plus. The amount of juice we have been discussing = a lot of heat. As nothing is 100% efficient, we have losses, and those are usually in the form of heat. Ultimately, we give heat back to the environment, again, nothing is 100%

The unit that is shown in the link I put up generates 24KWe when the sun shines. Based on what I read, it does not do anything to save the heat it collects, and they put it's efficiency @ 40% based on the total solar energy that hits the collector. Better than solar cells, and capable of recovering more than just the heat on the roof.

thoughts?


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## Tronthor (Aug 2, 2010)

...sorry that last one was so long.


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## aeroscott (Jan 5, 2008)

do some study on regen braking , temp differentials needed to run stirling engines make it very hard to get energy out of control er / motor( low grade heat ) . the most expensive part of the conversion are the batteries , to save on batteries , do what trains do, no trains, regen braking . good point on 40% solar @55 sq. meters 120 kw h /day or 85 miles @ 1400 watts/mile a big help .


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## Duncan (Dec 8, 2008)

Hi Tronthor

Stirling engines are heat engines

MAX possible efficiency = (High temp - Low Temp) / High Temp

So for 100C input rejecting heat at 30C = ((100+273) - (30 +273)) / (100 + 273)

equals 70 / 373 = 19%

(the 273 is to convert Celsius to Kelvin or Absolute)

If the heat input is higher the efficiency goes up

The units I used to work on had an input temp of 400C and 50C output 
giving a MAX efficiency of 350 / 673 = 52%

*They gave actual operational efficiencies of 11%*

The best thing to do is to use the motor for Re-Gen for normal braking and only use the brakes in an emergency


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## Tronthor (Aug 2, 2010)

Thanks for the info on the Sterling, I've just started to go back and rediscover everything I've forgotten while adding in real numbers and new tech.

I understand the Delta T being the key to the whole thing. I also do not know what sort of heat we are looking at from the controllers and inverters etc. Obviously if the losses were so large as to be making the sort of heat that makes the Sterling a major contribution, we wouldn't be sitting here talking in the first place.

I know that we have already thrown out the idea of an ICE+gen =>EV drive like a locomotive, but that would actually be the best of both worlds in this case. It is why those CSX adds can talk about how many hundreds of miles they can move a ton of freight on a gallon of dino juice.

The biggest factor is that you have steady state operation of the ICE spinning the gen.

Taken as a phased approach to this project, you do the following:

1) convert the Semi into an on-road version of a locomotive. (it's actually where I was thinking of going a a jump point for my RV project)

You want to size all of that for your steady state (cruising) condition such that you are producing say 110% of the required power to the drive wheels while running your ICE+gen @ approx 75-80% (in the world of Aviation, the ICE is sized, designed, and set up to produce 100% cruise power for 100% duty cycle of 2,000 hours without failure of any part (other than the lubrication oil which is supposed to be changed out @ 25 hours increments - not sure how you do this while flying, they never covered that....but they have figured out how to get you more dino juice!)

So, what this boils down to is a piston speed of 1600 feet per minute. I can't tell you why that is the number or how "they" decided on it, but that is the number. I'll bet that if you work out the piston speed on your ICE right now, you will see that - for the Semi and other continuous duty, long life, ICE that are meant to work and last (note, this excludes most cars, at least by their advertised numbers. My car, Hyundai Elantra GT (2004) w/ 5 spd manual has cont duty speed of 2970 +/- RPM - which does happen to work out to about 70mph, so they got that right - but is way below the performance numbers of the car, and the real power band of the engine doesn't hit until you run up over 3K RPM. Long stroke diesel ICE are much better. Conversly, my wife's new Kia Forte with their "high milage option pack" run a 5spd automatic with the same displacement (2.0L) runs @ 2K RPM @ 65 mph. They have done something right ... her car gets 45+ MPG on that ICE....which other than emissions begs the issue of the Prius (though it is not anywhere near as good in the local traffic demands and the Prius again wins, but the economics don't, the Kia is almost enough cheaper to buy it brand new and use it as a donor car for EV conversion and still have a little left in your pocket as compared to a new prius....) Sorry for the diversion...

So, going back to the right thread here, you set this up. Now you have to add many fewer batteries - they need to be there to pick up the load for acceleration and/or initial start from standing stop when your demand far exceeds the output of your generator.

The ICE+gen replaces some large % of the battery packs we have been talking about - plus it gives you the ability to recharge the pack you do have over night no matter where you are.

Since you do then have a real heat source, you can also incorporate a Sterling to assist in driving the gen, or, drive it's own gen. The Sterling would also be able to make use of the other heat sources we have discussed.

You also want to incorporate the regen option. Once you have paid the price to get 80,000 lbs to 80 mph (approx 84 Kwh if my math is correct ), it's nice to get something back for that....and you need a place to put it.

Once your batteries are full you have a problem though, so anyone with ideas on how to store that extra please chime in - a "heat tank" is an option, which is then fed back into the Sterling as space for the output becomes available - such as acceleration or climbing hills or driving at night when you don't have that sun heating up the trailer.

The system can be made as "complex" as desired so as to squeeze every last electron of useful energy out of the pool that we are sinking in. Conveniently, once it's all thought out and set up, the packaging is not so bad. A heat tank could easily be placed in place of one of the existing saddle tanks - a big thermos filled with a liquid salt as they are discussing for the solar thermal generation plants. They want MW, we want KW, it's just scale.

The last aspect of the "heat" system is that you use the otherwise too low a concentration of heat to run your water-ammonia absorption refrigeration circuit which cools the Human storage area, the cargo if required, and the cold side of the Sterling to boost that delta artificially. In the generation unit in the link I provided, they incorporate a regular old air/liquid radiator to cool the cold side ... they do not bother to even try to store that heat for use after the sun sets, but that is another thread...

At the end of phase one you have the EV side all set up. What is then left is the ICE side - which is greatly reduced in size and thus operation cost, pollution, etc.

2) Alternate source of fuel for the ICE - Bio-diesel for example.

2a) Replace the ICE with an ECE - namely a Sterling cycle engine which uses is an External Combustion Engine if you will. In this way you mearly have to supply a heat source.

The ICE is also a heat engine just as is the Sterling, the difference being that the heat is generated and used inside the cylinder - as has been mentioned, when the intercooler fails, these large ICE on the rigs don't do so well. Why? simple, the Delta in the temp (heat) and, in this case, the density of the working fluid: Heating hot air to make it hotter means that you start out with fewer molecules of air to pack energy into, starting out with the same volume of cold(er) air, means you have more "batteries" to pack the energy into. The whole thing relies upon volumetric thermodynamic efficiency to put power to the road.

A Sterling is no different with the exception that you have a fixed volume of working fluid and it is the heat delta you can impart to this between the hot and cold side that makes your power.

The Sterling will run on any fuel (so the issues of bio fuels in an ICE disappear), and need not actually rely on the burning of a fuel to get the heat - which brings us back to the system we are modifying. I've seen the numbers flying around, but don't have them at hand. The as-is ICE burns a set amount of fuel => this boils down to BTU's if you work the numbers the right way. From there you can figure out what sort of Sterling you would need if you wanted to completely remove the ICE and then be able to utilize whatever heat source you wanted to contrive.

3) Replace the ICE with whatever better technology there is - fuel cell for example (gets rid of the big gen and leaves you with a small one hooked to the Sterling - fuel cells output heat as well) combined with a hydrogen generator system to use up excess generation capacity on long distance down grades, panic stops, sitting in a lot in the sun etc.

I'm sorry for going very wide field here, but the application of EV in this instance is completely different than the application of EV to a small lightweight, streamlined 1 or 2 person commuter type vehicle. As such, the discussion has to step up to the "industrial" grade stuff. Look at the fuel consumption that Wicked listed in the beginning for the truck on a daily basis - hundreds of gallons of fuel. HUNDREDS - by contrast, my ICE car, consumes 1 (ONE!) hundred gallons in .... 1.5 - 2 months, so lets take all the small EV discussions and factor them up by say 50. Also, people are looking to get 100 miles range as a top end, Wicked is looking for 750 miles, round off to 1000 miles and we are talking another factor of 10.

So, the scale of the discussion is about 500X the discussion for an EV convert of a bike/ motorcycle / Ford Ranger Pickup (very nice ones out there) You could almost sow the entire Ford Ranger into the compartment where Wicked's ICE is now currently living - by volume you might actually be able to do it. Hell, I'm talking about an RV,and I can almost put 2 of them into his trailer!

Please, carry on .. this is great stuff.


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## Wickedtrucker (Jul 28, 2010)

First up Iamian. I didn't realize that with that 400 hp electric motor that was overkill hehe. I can't get away from regen for 2 reasons. first reason is that going down hill I would be seriously at a disadvantage as far as gravity goes. I have been on that ride once gonna try not to do it again. imagine a roller coaster that isn't attached to rails. that is what happens on a downhill grade in a truck. ever seen a truck that was smoking at the wheels? been there done that. will try not to do it again. Jake brakes or engine retarders are for slowing the truck down and standard brakes are for stopping. the second reason for regen is the obvious reason. going down those hills at a controlled free fall might as well use it to your advantage. Regen has to be part of the system for those 2 reasons. I wish I understood more about sterling engines but that sounds like a nice approach to more electric.


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## Tronthor (Aug 2, 2010)

I just found this on another thread here...

http://www.remyinc.com/docs/HVH410R2.pdf

This is the big brother to the motor used in the GM Tahoe hybrid. Of particular interest in the pass through shaft with the splines on the inside - you could mount as many of these in series as you needed, the limiting factor being your prop-shaft at that point. Being a " simple " shaft, it could likely be manufactured for low $$.

What I don't know is the regen side.

Can a permanent internal magnet DC motor be used for regen, or do you have to swap over to AC Induction motor? I had always thought that if you apply power to any electric motor, you get power, apply power to any electric motor and you get current out. Efficiencies are a different matter.

Anyway, the Remy motor above looks like it would certainly supply my needs for the RV, and a few of them in series would work for the Semi, allowing you to drop them out as the demand falls off, but give you a huge regen breaking ability if needed....

If you wanted to modify the trailer, replace the tag axels with drive axels, but hook the prop shaft to a motor, well, actually an efficient generator actually, and you have all wheel regen capacity to prevent the trailer coming around - a controller would simply have a tad more braking effect at the trailer wheels. I can't see where you'd ever want those wheels pushing, but if so, you have the option of using a motor rather than gen back there and you have the ability to drive the trailer.....


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## IamIan (Mar 29, 2009)

Wickedtrucker said:


> First up Iamian. I didn't realize that with that 400 hp electric motor that was overkill hehe.


Just remember there is a difference between continuous HP and Peak HP... or any engine ... Conventional OEM Diesel of Electric Motor.

From what you were describing you only needed a Peak or Maximum of about ~480 HP ... and you are not running your engine at 100% full throttle at that peak power 100% of the time ... so your continuous HP can be much smaller than the peak / max HP... my guess is you might be fine with a continuous rating of about ~240 HP ... but I don't know how hard you push your engine for what % of the driving miles / time.

Also food for thought.
2,000 ft/ lb of torque at 1,000 RPMs is ~380 HP ... even if the engine itself has a peak HP higher than that at some other point in the RPM power curve.



Wickedtrucker said:


> I can't get away from regen for 2 reasons.


No reason to get away from regen ... I was just saying don't over use regen ... regen is more efficient than friction brakes ... but not as efficient as conversing the momentum you already have.

Regenerative braking will also extend the service life of your conventional friction brakes ... Trains have been using it for decades ... although it wasn't until recently that they tried to store any of the energy ... they used to just throw it away into big heating elements on top of the train.


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## Tronthor (Aug 2, 2010)

Wicked, have not been on that ride - exactly - but RV's are way underbraked if you ask me. In fact, I really think that most of them should require that the drivers take and pass at least a CDL class... I've seen things that make my hair not just stand on end, but reverse and go back into my skin!

Anyway, yes, you want Regen for sure.

Torque is what makes you go

Hp is how fast and for how long you can deliver that torque

... sort of.

Hp is measure of work potential 
Power = Work / time = [force *displacement] / time

So big Hp means you can do more work faster.

My dad in an engineer. When he was young, he was on site at the final testing of a ship (naval architect as they call themselves) and noted that a unit they were testing had not been built right, but, that they were not going to complete the test correctly to prove it. The site foreman told him that if he could rig the ship for the test, they would do it. They went to lunch, he rigged this ship. They came back, did the test, broke the ship - back to square one.

Big deal.

Well, to "rig the ship", he had to move it. They knew this and figured it would end the discussion.

The ship happened to be big and made of steel - about the size of a destroyer.

They did not leave him the keys, a tug boat, any sort of thing to move the ship with....it was tied to the pier.

Well, you figure out how much Hp a single man has and you know what he had to use.

Moved the ship - "gearing" - by way of block and tackle and such - by the time they got back from lunch.

So, small power can do big work given the time to do so.

not sure if this helps clear up the Hp to torque comparison. The ICE in the semi has long stroke - lots of torque, but doesn't respond to throttle that quickly. ICE in a "rice rocket" has very short stroke and high power - but no torque until you get to high rpm's.

With tweaking the ICE in my RV can have same hp and possibly even same torque numbers as the ICE in the semi - but not for long (duty cycle/durability)

gotta run


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## speleocaver (Nov 17, 2009)

Check this out!

http://www.smithelectric.com/pdf/sev-us_newton.pdf


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## Tronthor (Aug 2, 2010)

speleocaver said:


> Check this out!
> 
> http://www.smithelectric.com/pdf/sev-us_newton.pdf


Well now, it seems that someone is about 10% there.

Hopefully I'll find out more information from Smith Electric. I have requested some information in my official capacity in my real world job.

We shall see.

Thanks for the info - perhaps one of the agencies I deal with will actually buy one of these things!


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## Tronthor (Aug 2, 2010)

Of note is that to haul 16,000 lbs of junk 100 miles @ 50mph, they have almost 10,000 lbs of chassis (and batteries)

Wicked, do you happen to have the curb weight of your rig empty of freight, but full of fuel and fluids? This would give us a very very gross comparison. We can assume that the actual structural portion of the 2 rigs will scale accordingly. The difference would be in the motive stuff.

Anyone happen to have curb weight of a truck like the one that SEV is selling? GVW 26,000, useful load of 16,000 ?? I believe that a local haul truck will have something like 200-300 miles worth of dino juice for the ICE...


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## Tronthor (Aug 2, 2010)

FYI: http://www.consenseus.org/downloads/policy/StateIncentives.pdf

Wicked, you talked about setting up a charging station at your home base. The link above lists some of the state by state incentives for such things as well as for the purchase of Alternative Fuel Vehicles for both individual and commercial ventures.

You could also show this to any of the truck stop operators you deal with who might be interested.

If you had a stop where you could plug into some high rate juice while you had lunch....would help you out with the battery situation.

...and I found the curb weight I was looking for:

http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2006/plenary3/2006_deer_clark.pdf  (vehicles in study page) 

It's an IH 4300, GVW 26000, curb weight 13,200 lbs.

So, on the surface, the SEV truck is more efficient overall - same payload with a lighter overall package. Since we are talking 4,000 lbs difference, it is more than just the delta between the ICE and the EV, so it may not be a fair comparison. However, grossly extending this, we are looking at a 20,000lb difference between the ICE semi and the EV semi - for a 100 mile range anyway.


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## Wickedtrucker (Jul 28, 2010)

The curb weight of my truck with no freight is currently 34,000 lbs and some change. That is the trailer and full of fuel. I still need to get an empty weight of just the tractor tho.


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## Tronthor (Aug 2, 2010)

Wow, so much for gross estimations, there is no way that we could end up with a rolling stock at 14,000 lbs as EV (though, if we figured it for 100 miles, I wonder what it would be?)


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## TX_Dj (Jul 25, 2008)

Tronthor said:


> Anyone happen to have curb weight of a truck like the one that SEV is selling? GVW 26,000, useful load of 16,000 ?? I believe that a local haul truck will have something like 200-300 miles worth of dino juice for the ICE...


M35A1 "Deuce And A Half" is 13,530 curb, GVWR 23,530. That leave 10k for useful load, a little shy of your request.

M818 "5-Ton Tractor" is another similar example, 20,290 curb, GVWR 37,500, 15k for payload.


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## Tronthor (Aug 2, 2010)

Thanks for the curb weight comparisons.

I was thinking that they had gotten some large advantage out of the EV side of it over the ICE + fuel, but doesn't look like it ... which is good, since we'd have to figure out how next.

I wonder if building the structure of the Semi, tractor anyway, out of composites would be an option?

With the EV, you do not have the vibration issues (if we ended up with the hybrid along the lines of the locomotive, the ICE or ICE Equiv +gen would be mounted on isolation foundations in order to keep the smooth silent portion of the EV as true as possible.

You also don't lose the weight on the wheels, since you are going to replace the missing steel with batteries.

granted this rules out a straight conversion - unless you did it by going "frame off" and replacing the frame rails with purpose made carbon fiber rails and such....which gives you more options for where the batteries and such would go since you can design and build the frame to purpose. Thus getting the weight as low as possible and distributed for best traction and handling - you could end up with a better rig than you started with. Some engineering would be required since this is all materials, form, function stuff...and critical.

In fact, once the feasability numbers are worked out and a final "project" were arrived at, you would have to do the engineering anyway in order to get it past DoT and the insurance companies.

Always hidden fun to be found.


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## Wickedtrucker (Jul 28, 2010)

Actually the tractor and trailer I currently drive has a curb weight with fuel of 34,000 lbs. That's not to say it can't be lowered by a major amount. If you speced for more aluminum in the truck and built the cab and hood out of carbon fiber you can seriously bring down the weight. Also switching to a daycab versus a sleeper, which I have a sleeper on my truck. Total weight after lightening up the truck would bring weight down to 28,000 to 30,000 lbs. depending on what is changed. My truck is built cheaply not for weight savings. If I was to ever try a project like this it would be with a light weight spec. Not with a standard cheap company spec. We as owner operators can spec every part of the truck individually according to our needs. even bolts and the frame can be respeced on a truck. Nothing is off limits on a $100,000 truck. Trailers can be respecced to all aluminum as well. I have had a Benson flatbed trailer below 9,000 lbs. So a 10,000 lbs refer trailer shouldn't be unattainable. Match that with a 13,000 lbs daycab. and you have a curb weight of a class 8 at just 22,000 lbs with fuel. that leaves 58,000 lbs for freight if you think you needed it. or if you want it leave room for an additional 12,000 lbs of batteries and 46,000 lbs of freight. hows that for playing with the numbers.


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## Tronthor (Aug 2, 2010)

That is some serious play time! I didn't realize that you could get that specific in the spec, just that you could spec it all out.

given your particular requirements, I'd keep the sleeper cab, just have to be careful on the spec of it - carbon fiber/aluminum honeycomb with rigid sheet or blown in expanding foam for insulation for example....and a carbon fiber structural frame (as light or lighter than aluminum and much stronger)

The ideal rig would have all the required creature comforts, all the weight of the lightest build you could spec, and room enough for all the required batteries along with the highest efficiency EV that we could come up with.

The Remey motors have the same flange and bolt pattern as the Allison transmissions, so you can bolt in a very nice stick shift ... and from what I understand, you only have to let up on the "gas" to shift - no clutching needed ... so perhaps a control system change for the tranny might be required (no idea how the allisons tie into the truck ICE control etc...) 

They may prove to be the correct choice.

Now, I have a question for the more experienced: All the formulas from physics, speak about Mass, as opposed to Weight. However, when looking up various references which specifically speak to sizing things in the EV world, it is not clear if they actually use the Weight or the Mass.

For example, this spreadsheet: 

http://www.cameronsoftware.com/ev/EV_CalculateMotorSize.html

they have a macro that arrives at the power to maintain speed on any given grade (use 0 for flat). However, going back to my multitude of physics classes, all those equations use MASS, not WEIGHT. Yet, if I take the GVW for my intrepid RV of 15000 lbs (weight, as determined on a scale), and convert it to Kg (2.2 kg/lb) and then factor out gravity (9.8 m/s^2) I get one number, and if I leave in the gravity (weight) I get another one - as one would expect.

So, to run my not so incredibly large box down the road at 65 mph on an impossibly horizontal run of road should require either 90 KW or 104KW, and the power to accelerate to speed over 19 seconds is either 15KW or 153KW - this makes sense as we are talking factors of 10 more or less. But this is a big difference in sizing both the motor and the pack to drive it.

I am going to suggest that they did factor out gravity as the power required for level flight from the sheet is near the scratch pad numbers I came up with on my own....but, some words from someone who's been there would be grand....just to restore my sanity.... cuz mass is weight by 9.8 after all (okay, I'll stop trying to be witty) 

Thanks.


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## Wickedtrucker (Jul 28, 2010)

whoa dude how bout dumbing that down for us mentally disabled. anyway I have a question where are the batteries going that you plan on putting on that RV? I always thought they used every bit of space in those motorhomes for creature comforts. Anyway it's an awesome idea my brother has been wanting to build one of those for almost 10 years now. But he wanted to keep it completely off grid.


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## tomofreno (Mar 3, 2009)

Multiplying by the conversion factor of 2.2 lb per Kg converts a mass to the approximate force, in Pounds, due to gravity on that mass, or it's approximate weight at earth's surface. So there is no need to then divide by the acceleration of gravity, 9.81 m/sec squared.


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## Tronthor (Aug 2, 2010)

Well,okay, here goes...

For those of us not so mentally deranged as me (shouldn't be hard, I'm nothing if not deranged), I was talking about the difference between weight and mass.

Mass - a quantifiable characteristic of matter. It is a constant for any given "thing" regardless of where it is. Mass is an inertial property, and as such is related to what magnitude of force is required to change its direction 

Weight - a measure of the effect the local gravity on a mass.

Example: Here on Earth, my motor home weighs 15,000lbs GVW, on the moon, my RV would tip the SAME scale (assuming we took it along for the ride) at 2,500lbs.

Whereas on the ride between Earth and the Moon - once we were coasting and not under and acceleration - the same scale would show a weight of 0 lbs. However, the RV would still have it's mass, and that mass would be the same (we are assuming that the RV is a payload and not the thing getting us to the moon in the first place, or else the mass would change as we burn fuel - yep, I was considering being a rocket scientist at one time...told you I was deranged)

The question that I had posed was in relation to the formulas from physics and engineering (well, physics ) in which they require Mass as opposed to Weight. In addition, the link I put up is to a spread sheet where you enter the "mass" and it calculates a bunch of stuff for motor sizing and such. My question there was, is it the mass or the weight since I see these terms get used interchangeably and incorrectly a lot.

Which brings us to the 2.2lbs/kg factor... which is a unit conversion factor for MASS from English units to SI (aka Metric) units which are Kg, or Kilograms - which the spread sheet is written in.

So, applying 2.2 to the GVW (weight) does not give me Kg (mass), it yeilds Kg-force. Technically force is Newtons (N) which is 1 Kg-M / sec^2 or
1 kilogram meter per second squared.

Force is applied energy. F=ma, Force = (mass)*(acceleration) so, in our standard units, ft lbs / sec^2 or foot lbs per second squared

or

mass moved a distance per unit time squared.

this is the force required to accelerate whatever our vehicle ends up weighing (massing to be correct) at a given rate of acceleration. Think of it in that well known 0-60 time.

you can also think of this as weight, since weight is only realized when the force of gravity is opposed. Thus, the force applied by the earth's surface on the bottom of the scale is the same as the mass of the object times the acceleration of gravity (32 feet per second squared is the average for earth, this is 9.8 meters per second squared in SI or Metric units)

So, if you put the RV on a wet ice rink, on it's side (more surface area) and try to move it sideways, you will be very close to dealing with only its mass, whereas, if you try to lift it up from the ice, you have to deal with its weight.

This all plays into the calculations for our EV's in the sense that cruising power on a flat road almost does not care about the weight, it almost does not care about the mass either - it is the air resistance, which depends on the density of the air (temp, humidity, altitude (aka, pressure)) and the flat plate (or "whetted") area (aka, silhouette as seen perpendicular to the direction of travel) and the speed you are going, and, the infamous coefficient of drag (for the average "semi" this is more or less about 0.7, while a Porche 911 is someplace down around .3. This cruising power factor also has to deal with the rolling resistance of the tires - which does depend on the weight of the vehicle, and the specific tires it has, and the losses (efficiency) of the drive line.

It's all very complex if you want to get the _exact_ numbers.

Now, once we get off of a flat (0 % grade) road, the weight starts to factor in to the power requirement, it also factors into the control and stability issues as less normal force (force applied perpendicular to the road surface - on the flat this is straight down, on a sheer vertical cliff, this is parallel to the flat road, and thus cars and trucks fall off of vertical cliff faces and fall rather than drive up them - unfortunately) is available to stick the tires to the road.

As I said, it gets tricky.

So...Mass versus Weight - a heavy subject.


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## Tronthor (Aug 2, 2010)

As for the batteries in the RV,

Yep, they use as much of the space as they can, but, they do it badly.

Plus, if I'm doing a true "locomotive" style hybrid, I lose the 400 lb generator that is the back, and can probably cut down on the 88 gallon fuel tank. I can also relocate the 55 gallon fresh water tank.

Most likely though, if I do this, I'll be looking at 50 mile range on batteries, with the rest being handled the way a train does it.

Keep in mind that in an off-grid or "dry" camping situation, you need the generator for power anyway, so you have to drag one along - there are other options since we are talking about much less power than sustained cruising on a flat or low % grade road. Options such as solar PV, wind, solar concentrators to PV or the newer Sterling Engine/Gen designs ... or something, but you still have to move it where you go, you still have to be able to set it up in a favorable location - if your site is wooded, solar anything and potentially wind are both sunk.

So, if I have to drag a gen around, why not ramp it up just a bit so that I can have cruise power + on say a 3 or 4% grade (effectively averaging out the roads to "flat") at whatever speed I want, 65mph in this case. Then I am able to put power back into the much smaller battery pack while driving so that I have the extra juice to pull out and pass, climb a hill at speed - for a while anyway, then we slow down - and I have a big "house" battery for camping and only have to run the gen a limited amount while camping, and then before we pull back on the road - so you run it all day the day before you plan to break camp, or at night if it's just a layover.

The gen that I have is 6kw...attached to a 20 hp engine. I figure, at least on a first pass, that I need about 80kw to cruise (100 hp +/-) - I used some really gross numbers to figure out the wind resistance and such. So, for all intents and purposes, I need about 50% of the ICE that I have there now - assuming that I can store that extra that I need to accelerate and climb hills. The ICE has a 4 barrel carb on it, and at 55 mph, I've not even opened up the pair of larger barrels (Chevy 454 if anyone is interested) so I know that cruising is using a mere fraction of what I'm dragging along....and doing so very inefficiently.

The goal then is to reduce the size of the ICE as much as possible, and to run the inevitable ICE at its best efficiency to reduce the dino-juice that needs to a minimum along with the associated pollution.

If however, it can be shown that I can drive for whatever - 10 hours (have done 14 hour days...I do NOT advise it) on EV alone, and be able to run the on board gen overnight and recharge ... well then, that changes everything.

It's why I'm here on this thread in the first place.

Hopefully I haven't drive you all to the edge of insanity - or boredom - and I look forward to comments ... and to getting back to our long haul rig situation as well. If we resolve that, then my situation is a no brainer.

Thanks,
Tronthor


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## rillip3 (Jun 19, 2009)

Tronthor said:


> ...
> The Remey motors have the same flange and bolt pattern as the Allison transmissions, so you can bolt in a very nice stick shift ... and from what I understand, you only have to let up on the "gas" to shift - no clutching needed ... so perhaps a control system change for the tranny might be required (no idea how the allisons tie into the truck ICE control etc...)
> ...


In a lot of commuter car EV conversions there is no clutch needed, but this is because the synchros can take care of it. They can only do this because the EV motor is so much less mass spinning than the ICE. Given the kinds of torque and gearing involved in such a large vehicle, I would probably have to recommend keeping the clutch (some commuter car EVs do this as well).


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## aeroscott (Jan 5, 2008)

when I was learning to drive truck ,I was told not to use the clutch except for starting off in low gear . it works very well , but the engine rpms tend to fall off quicker then you can shift ( lots of missed gears , clutch or not ) . the fix is to just keep a little pressure on the throttle so rpm's don't fall to fast . I would think the e motor would coast down without loosing rpms to fast , giving more time to get the next gear . In the truck trans, use of the clutch didn't help to match gear speeds in order to make the next gear (up shift or down shift).


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## rillip3 (Jun 19, 2009)

aeroscott said:


> when I was learning to drive truck ,I was told not to use the clutch except for starting off in low gear . it works very well , but the engine rpms tend to fall off quicker then you can shift ( lots of missed gears , clutch or not ) . the fix is to just keep a little pressure on the throttle so rpm's don't fall to fast . I would think the e motor would coast down without loosing rpms to fast , giving more time to get the next gear . In the truck trans, use of the clutch didn't help to match gear speeds in order to make the next gear (up shift or down shift).



Well I guess if you normally drive without a clutch, driving without a clutch wouldn't be a problem.


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## tomofreno (Mar 3, 2009)

> Which brings us to the 2.2lbs/kg factor... which is a unit conversion factor for MASS from English units to SI (aka Metric) units which are Kg


 Look at what you wrote: 2.2 lbs/kg. Pound, lb, is force, not mass. The unit of mass in the English system is slug. One pound is one slug accelerating at 1 foot per second squared. The 2.2 conversion factor multiplied times a mass in kg converts it to the weight, a FORCE, of the object at the surface of the earth. If you want to convert units of mass, one slug is equal 14.59 kg. Sorry to distract from the topic of the thread.


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## Wickedtrucker (Jul 28, 2010)

Yea most truckers don't use a clutch. I can drive with or with out a clutch easily. when doing road tests at new jobs I usually float the clutch so that it looks like I am actually using it to the road tester hehe. I so sneaky... I just make sure all the other testers go first so they don't get to see me float the clutch and rat on me or try to copy my originality. Most of the testers know what I am doing anyway, if they are top notch drivers, but stay silent for whatever reason.


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## sgtlethargic (Sep 17, 2010)

tomofreno said:


> Look at what you wrote: 2.2 lbs/kg. Pound, lb, is force, not mass. The unit of mass in the English system is slug. One pound is one slug accelerating at 1 foot per second squared. The 2.2 conversion factor multiplied times a mass in kg converts it to the weight, a FORCE, of the object at the surface of the earth. If you want to convert units of mass, one slug is equal 14.59 kg. Sorry to distract from the topic of the thread.


Doesn't the problem stem from the misuse of kg as weight not mass? In other words, it seems that kilograms are very commonly used for units of weight when it should be Newtons.


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## TEV (Nov 25, 2011)

The big problem are the batteries. We just got the lithium batteries which barely give a car a decent range, a huge improvement from the lead batteries but still not an equal to an ICE when talking about range and recharge.

In order to get an EV semi truck you will have to wait for the next technological leap ( batteries or maybe a mini nuclear reactor  )

And for sure, an EV semi truck will have an AC motor and a very high voltage.


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## Siwastaja (Aug 1, 2012)

To OP;

The only way I see this becoming reality would be a large industrial AC motor, a high voltage battery pack and a surplus industrial (or DIY) inverter.

You just need regen for something big like this; trucks are designed to do some motor braking as you probably know very well.

You also need high voltage.

The good news are that you also should have plenty of room for a physically large and heavy industrial motor (and inverter). Industrial ACIMs also go higher in efficiency the bigger they are. I'd just get something like 150-200 kW or more, 6-pole motor with 400V spec and inverter duty insulation, and build a 800-1000V battery pack.

This kind of electric drive is nothing special in the industry, the parts are all there; you just need to use that technology and forget DIY products.

And as a reality check, don't expect this to have long range, unless you are very rich. 

A good truck diesel engine is just fine for long range operation when you drive without stopping much, outside towns. I don't see any reason to replace it with electric drive with current battery technology (yet)... 

But for short-range purposes (deliveries within a city, moving stuff between two nearby towns, etc), you could save your money back and do your part in increasing air quality.


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## Ziggythewiz (May 16, 2010)

To all recent posters:

Please don't hold your breath for a response from people who haven't visited this thread in 2 1/2 years.


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## Siwastaja (Aug 1, 2012)

Didn't notice the date, just that this was on top... But I _think_ at least someone else could be still thinking about a similar thing.


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## TEV (Nov 25, 2011)

Probably my fault, but I was using the "new posts" function, so I didn't check the date.


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## Ziggythewiz (May 16, 2010)

I think there was a spammer that posted a random comment to resurrect the thread. I don't see it anymore so they must have been removed.


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## mizlplix (May 1, 2011)

I could see this idea work under a fixed circumstance, like from a rail yard to a produce warehouse and back on a daily basis. Something like a City-delivery short wheel base "Bobtail".

After all, there are city transit buses doing it.....

It is hard to beat a class A truck over the road for customized route efficiency.

Just as it is hard to beat the railroad for point to point tonnage.

Miz


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## arklan (Dec 10, 2012)

this was such a fascinating read.

i was thinking that the weight of the car without the batteries and motor would be something like 1 tonne there abouts average.
and the weight of the motor with batteries and everything that goes with it would add up to about 400kg im guessing?
so 1400kg vehicle with 28% of the total weight being the propulsion
if you scale that up with the prime mover being about 15 tonne then thats 4.2tonne for propulsion.
a regular car is efficient because it doesnt need to move much weight, and the prime mover would probably be efficient given all of the same percentages.
but the same applies that if a truck has to tow an extra 25 tonne thats 1.6 its own weight extra
if you had to do that with a regular ev car towing 1.6 times its own weight of 1400 and so has a 2.2tonne trailer behind it, its gonna struggle like mad
just wanted to add that coz it was such a fascinating read


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## PStechPaul (May 1, 2012)

This was an interesting thread, and even in 2010 it seemed just about reasonable. What I found most encouraging was the figure of about 10 MPG for 40,000 pound trucks. This is actually comparable to many 1 ton pickup trucks. So a reasonable point of comparison might be a typical pickup truck with a normal fuel economy of 20 MPG where a conversion might take 400 Wh/mile, or even a 40 MPG car that takes 300 Wh/mile. Based on fuel usage, the semi truck might reasonably use 800-1200 Wh/mile. A semi rig has a lot higher weight to frontal area ratio, so aerodynamics are not as critical, and it also means that regeneration on long downhills might recoup much of the energy spent going uphill, especially if that were at lower speeds where windage is less significant.

The 750 mile range is daunting, but at 1kWh/mile that is 750 kWh, and if LiFePO4 can be obtained for $0.35/Wh, it would cost a little over $260,000. At about 8 grams/Wh this would be 6000 kg or 13,000 lb.

The 1kWh/mile at 60 MPH means an average of 60 kW or 80 HP. Since a truck engine may be 400 HP peak, a 200 HP electric motor should do nicely, and I found one for about $2200, and it weighs about 2000 pounds.

200 HP drives are available for $5000-$15,000 and weigh about 300-1000 pounds. 

So the entire project would be about $300,000 and weight would be 16,000 pounds, but the original engine and other ICE parts might subtract 3000 pounds from that. The main problem would be recharging the 750 kWh in 10 hours which would require 75 kW, but that's only a 100A 480V three phase service, which is quite common.

Considering that the OP spends $150,000 a year in fuel costs, and the daily electric charge is only $75 or $27,000 a year, it seems very much worthwhile.


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## ruckus (Apr 15, 2009)

Well, just to throw this out there. You can get a BLDC bus motor that puts out over 1100 Nm torque and pair it with a Scott drive 250R (900A 400V) controller for 360kva of power.

If you need more, double it.

Cheers


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## Wickedtrucker (Jul 28, 2010)

mizlplix said:


> I could see this idea work under a fixed circumstance, like from a rail yard to a produce warehouse and back on a daily basis. Something like a City-delivery short wheel base "Bobtail".
> 
> After all, there are city transit buses doing it.....
> 
> ...


sorry haven't had my laptop to reply to these most recent posts. But this one I know for sure that they already use electric trucks in LA Ports and Rail yards as drayage trucks. they only go about 25 mph and are for about 8 hour shifts but I am waiting to see if i can find one of them after they got hit by a train or a crane....  but i would probably still not be able to afford them as they are $100,000 trucks new.


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## subcooledheatpump (Mar 5, 2012)

This screams Industrial Induction motor. 

Regenerative braking, that mean less brake wear

Higher speed range, less gears. 

Cheaper than BLDC 

No burned brushes, and constant torque. 


Anyway, My thoughts. I've always thought about making (or converting) a much larger electric truck, Just not a semi tractor/trailer. I'm sure we've all seen those box trucks, but I'm talking about the kind that aren't based around a van, but based around a heavier diesel front end. 

Converting one of these means more room for the batteries under the frame (I think? I'm not sure of the semi tractor dimensions) And possibly mounting a liquid cooled industrial inverter under the frame as well, or where the fuel tank was mounted by the step up to the cab. I've looked at a few of these trucks and I find the rear end ratios are very diverse, so you could pick one with a high rear end ratio so the motor wouldn't need to produce insane torque. It could be smaller and turn faster just as is done in electric cars. I figured the weight of the batteries would be important but it wouldn't be too critical as these vehicles are rated to carry heavy loads anyway. Maybe I have the wrong idea about this but I'm thinking the greater the weight capacity, the greater the range. Since weight (or mass really) only affects the truck during take off. Steady driving is all about aerodynamics. Just my thoughts


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## trukr (Mar 17, 2013)

400hp would have to be a minimum nominal not peak hp rating. It would take a lot more than a 10s burst of power to climb a hill in a rig. I can smoke a few cigs in the time it takes me to climb the snowshed hill on the coquihalla with a full load. (aka highway thru hell)

Also you would need to use dynamic braking regardeless of regen or not. You need something to replace the jake. Really not fun to lose your brakes down a twisty steep hill. Trust me.

Battery placement shouldn't be an issue if you also use the trailer frame to hold batts. Run a tridem axle for the extra weight and carry only double axle loads. Forget the sliding axle and slide the battery pack instead to shift weight for the chicken coup.

What I really like about the concept of an electric rig is the possibility of drives on the trailer. Would be excellent for a snowstorm mountain pull and AWESOME to have dynamic braking on the trailer as well. You can't have a driveshaft to the trailer, but you sure as hell can get cables back there.


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## Woodsmith (Jun 5, 2008)

trukr said:


> You can't have a driveshaft to the trailer, but you sure as hell can get cables back there.


Ahem!








Multidrive by AWD as used on Bedfords, Scammells, Fodens in the 1980's.


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## trukr (Mar 17, 2013)

Ha ha NICE, I stand corrected  
I've never seen anything like that before.

It would not suit my driving style though. I get lost so often I can't live without the ability to do a jack knife u-turn.


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## Ivansgarage (Sep 3, 2011)

Here is a 200 hp 4 pole motor what a monster, could not even imagine
trying to power something like this with batteries, and what controller???


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## subcooledheatpump (Mar 5, 2012)

The controller would probably look like this. 

I think they are available in liquid cooled versions too


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