# If it can work



## bug man nrg (Aug 30, 2012)

If it can be done 
144volts @ 110Ah how much power would you need to keep a car running for more than 300 miles or more Charging on the fly?


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## Ziggythewiz (May 16, 2010)

Distance is irrelevant if you're charging at your continuous usage. What matters is primarily the speed and surface area of the vehicle.

At 144V my car would need ~60A to run continuous at 45 mph.


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## onegreenev (May 18, 2012)

bug man nrg said:


> If it can be done
> 144volts @ 110Ah how much power would you need to keep a car running for more than 300 miles or more Charging on the fly?


As much gasoline as you can stuff into your vehicle to power the generator needed to keep the batteries charged on the fly while driving with an electric motor. 

Or just stuff in enough lithium cells to go 300 miles and forgo charging on the fly. No gas is better. Won't be cheap.


Won't happen with lead acid. Too damn heavy. 

You can go 25 miles with lead


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## bug man nrg (Aug 30, 2012)

Distance is irrelevant if you're charging at your continuous usage. What matters is primarily the speed and surface area of the vehicle.

At 144V my car would need ~60A to run continuous at 45 mph.

is this with a 5 speed ??
and what volts would you need???


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## Ziggythewiz (May 16, 2010)

That's running in 2nd gear, but it would be similar otherwise.

I run at 120V, but I gave you what it would be if I were at 144V, since that's what you asked. Every car's different though, so you need to find something similar to what you have planned from evalbum or the garage here, and see how much they use.


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## bug man nrg (Aug 30, 2012)

I have a Nissan truck and i would like to dive it like the IC engine .
So what amps do you pull in 3rd on the free way ??
I have some egg heads looking into this for me and i would like 200-300 mile before a plug in


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## PStechPaul (May 1, 2012)

It's a simple calculation if you know the Wh/mile of the vehicle under the given conditions. A lightweight, aerodynamic vehicle might achieve 200-250 Wh/mile, but a truck is probably 300-400. So 300 miles would be 90 to 120 kWh of energy. Lithium batteries are about $400/kWH, so you're looking at $40,000 worth of batteries, and probably 1000 pounds or more. You can get lead-acid for about $70/kWh, or $7000, but they would weigh over 6000 pounds, and you'd need to have them on a trailer and tow them. Then your energy usage would probably double to 800 Wh/mile, and you'd need twice as many, and .... yaddayaddayadda ... not going to work. 

If you charge on the fly, you'd need a generator capable of 10 kW or so, and the entire system would likely be less efficient than a good diesel engine (or even a gas engine).


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## bug man nrg (Aug 30, 2012)

OK i see where is is going BUT I THINK I MIGHT NOT HAVE COME ACROSS RIGHT 
What i need to know is 144 volts is what have to work with will 160 volts with 60 amps keep me going ????


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## Ziggythewiz (May 16, 2010)

At sub-freeway speeds, yes.


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## bug man nrg (Aug 30, 2012)

But at freeway do you not pull less amp ???
ie 65 mph is that not less amp than stop and go in town ??
So 160 volts DC with 60 amps out put Charging work on the fly ???


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## PStechPaul (May 1, 2012)

There are many factors involved. Vehicle weight, rolling friction, drag, and acceleration, as well as efficiency of the battery pack, controller, motor, and drive train. Freeway driving also involves some up and down grades, which are actually acceleration, and there are also wind gusts from other vehicles or weather conditions, and some acceleration and deceleration from normal driving.

You can use my calculator to see what power is needed under various conditions:
http://enginuitysystems.com/EVCalculator.htm

For a 2000 kG (4400 lb) vehicle at 80 km/hr (50 MPH), and 0 acceleration, I show 15 HP or 11 kW. But for only a 1% slope (or equivalent 0.01G acceleration), the power is 20 HP or 15 kW. Your 160V at 60A is just about 10 kW, so you might just barely achieve what you want on a flat road. At 65 MPH, however, you need 22 HP or 16 kW. Speed does make a big difference, but Wh/mile does not change quite so drastically.


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## Ziggythewiz (May 16, 2010)

It depends on many variables, but the average for low highway speeds seems to work out about the same as for local because of the continuous use instead of stop&go.

You asked continuous though, so I gave you that, not average.

At 45 mph my continuous usage is ~60A @ 120V, or 7.2kW.
My average, however, is nearly 100A or 12kW...which is what I would expect to use continuous at 60 mph.

For local driving continuous and average will be quite different, but for long distances they will be nearly equal.

I have a very little car though, and a truck's aero is no better than my brick, so unless it's a small truck your numbers could be much worse.

They'll also get worse for real highway speeds, like 70+mph.


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## Ziggythewiz (May 16, 2010)

PStechPaul said:


> You can use my calculator to see what power is needed under various conditions:
> http://enginuitysystems.com/EVCalculator.htm


I tried to use your calc to estimate the difference between what I know well (45mph) and highway speeds (60-70 mph) but I couldn't get the numbers to look remotely reasonable at 45. Even if I turned the aero and drag numbers down by orders of magnitude it still showed over double the actual power requirement.


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## PStechPaul (May 1, 2012)

I'm not 100% sure I have the formulas correct, but they seem to give reasonable results. What are the parameters you have? You might have left the default 0.1G acceleration in place (which is 0.98 m/s/s). With zero acceleration, my calculator shows a 1400 kG (3100 lb) vehicle with default parameters needs only 9.6 HP or 7.2 kW to roll at 45 MPH which is what you observe. And at 60 MPH it gives 15 HP or 11.3 kW.

If there is an error I'd like to correct it. Thanks.


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## Ziggythewiz (May 16, 2010)

Yup, that's what I missed. Thanks.

So the calculator shows a required power increase of ~57% cruising at 60 instead of 45 then another 31% to cruise at 70, and another 29% at 80.

At 70 mph you're using roughly 2x the power used at 45 mph.


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## bug man nrg (Aug 30, 2012)

I am trying to work this out .due to i tune IC engine with efi and at 60mph it only take's 21hp-25hp to pull a F150 truck with the AFR @ 14.3/1 .
So am i on track with my line of thinking ??


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## PStechPaul (May 1, 2012)

Maybe you can do some research to see if anyone has Wh/mile figures for an F-150. I found this:
http://www.hypercars.com/main.html

It lists a 2008 F-150 at 2618 Wh/mile and 14 MPG. Assuming 25% efficiency, an electric conversion might be 654 Wh/mile. At 60 MPH that would correspond to 654*60=39kW or 53 HP. That seems high. But if you use 20% ICE efficiency, it becomes 42 HP, and if the F-150 can get 21 MPG highway, then it becomes 28 HP. Note that even a Prius uses 800 Wh/mile, but that is probably based on gasoline usage, which may be as good as 33% efficient running the ICE at its "sweet spot". So on electric only it would be 267. The plug-in Prius is listed at 260, so that's a good reality check.

It looks like the F-150 is an example of the very worst fuel economy other than obvious guzzlers such as Hummers and heavy trucks. My 1989 Toyota 4WD pickup gets at least 21 MPG on highway. It has a cap, so that might help. But you should not be too optimistic. Check the EV gallery to get some real figures for F-150 conversions.

BTW, I assume AFR is air/fuel ratio for the on-board ICE generator. How does that translate to efficiency? And how heavy will the generator be?


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## bug man nrg (Aug 30, 2012)

Thanks this info will help me on the way with what i am doing


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## bug man nrg (Aug 30, 2012)

we are playing with this thing a lot more than doing work right now


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## bug man nrg (Aug 30, 2012)

bug man nrg said:


> we are playing with this thing a lot more than doing work right now


we had had a long time playing with this and we might have a working part soon for this project


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