# I suck at math



## TheAtomicAss (Feb 19, 2009)

And that is why I'm asking someone more numerically-minded to double-check my figures. 

Using the SE 400AH cell as a guideline, I come out to needing approximately ~721 cb. ft. of space for 2,250 cells. Does this sound about right?


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## Tesseract (Sep 27, 2008)

Close enough... 71mm thick x 283mm tall (not including battery cables) x 450mm wide = 9,041,850 mm^3 per cell. Plugging this into an online volume calculator gives 0.3193 ft^3 per cell.

Ummm... 2,250 400Ah cells? Do I even want to ask what this is for?


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## Amberwolf (May 29, 2009)

Sounds like enough to run an RV...or a laser satellite killer. 
________
Gisselle


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## TheAtomicAss (Feb 19, 2009)

Amberwolf said:


> Sounds like enough to run an RV...or a laser satellite killer.


Well, you were right in your first guess, but unfortunately for the world, you've given me an idea in your second...

MWUHAHAHAHA!


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## TheAtomicAss (Feb 19, 2009)

Tesseract said:


> Ummm... 2,250 400Ah cells? Do I even want to ask what this is for?


Electric RV.


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## crackerjackz (Jun 26, 2009)

2,250 X 400aha cells ... jesus you wanna do an endurance test with a tank ??


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## TheSGC (Nov 15, 2007)

TheAtomicAss said:


> Electric RV.


You do realize that is nearly a million dollars in cash, right? (USD).

400 Ah * $1.1/AH * 2250 = $990,000 USD.

And that's 2.88 Mega Watts of power. If you really have any remote idea of spending that kind of money, that RV better be able to drag race. I can see the headlines, White Zombie vs the Winnebago......


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## TheAtomicAss (Feb 19, 2009)

TheSGC said:


> You do realize that is nearly a million dollars in cash, right? (USD).
> 
> 400 Ah * $1.1/AH * 2250 = $990,000 USD.
> 
> And that's 2.88 Mega Watts of power. If you really have any remote idea of spending that kind of money, that RV better be able to drag race. I can see the headlines, White Zombie vs the Winnebago......


I can see myself now... 45', Somewhere between 80-120K pounds, and quarter mile times in the low 6's. 

Seriously, if I ever drop the hammer and run it 3C, I'll be putting out almost 10,000 HP, AFTER factoring in efficiency losses. 

As for the cost, the batteries are only 1/3 of the total budget. It will be a fully decked-out luxury vehicle, of course.


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## Drew (Jul 26, 2009)

You might have made some errors in your initial calculations, not only is it 9 cubic meters of batteries but its also 32 tons.

It will also take well over 1000 hours to fully charge on single phase power and would be capable of doing a few thousand kms before you run out of charge.

You'd need a very large truck to carry the batteries and you'd need a few days to charge it off a full blown three phase power point.

Why do you need so much power?


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## Amberwolf (May 29, 2009)

Drew said:


> You'd need a very large truck to carry the batteries and you'd need a few days to charge it off a full blown three phase power point.
> 
> Why do you need so much power?





TheAtomicAss said:


> Electric RV.


http://www.diyelectriccar.com/forums/showpost.php?p=130633&postcount=11

I wanna ride in it at least once. 
________
Los angeles marijuana capsules delivery the farmacy


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## Woodsmith (Jun 5, 2008)

Amberwolf said:


> http://www.diyelectriccar.com/forums/showpost.php?p=130633&postcount=11
> 
> I wanna ride in it at least once.


Maybe one of these would be a more suitable power supply.


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## Drew (Jul 26, 2009)

Woodsmith said:


> Maybe one of these would be a more suitable power supply.



I think thats more realistic than the batteries, the batteries would weigh at least 32 tons, no bus that I'm aware of has a GVM of over 31 tons.

I would imagine that the tare weight of a large bus well over 15 tons which means that you won't get the 32 tons to put batteries in.


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## TheAtomicAss (Feb 19, 2009)

Drew said:


> You might have made some errors in your initial calculations, not only is it 9 cubic meters of batteries but its also 32 tons.
> 
> It will also take well over 1000 hours to fully charge on single phase power and would be capable of doing a few thousand kms before you run out of charge.
> 
> ...


I figured on the weight, it's the physical size that I'm still trying to shoe-horn into my design. I've got 45'x8.5'=382sq. ft. of space, so the batteries would have to be about 2' above the bottom of the chassis, completely front to back. Which is why I'm hoping SE comes out with higher-capacity cells that are physically more power-dense, sometime before I begin construction.

As for charging, I had intended to setup the charger to run off anything from a single 2-phase 240V 50A connection, all the way up to 2 separate, 480V 100A 3-phase connections. Oh, and the roof will be completely covered with solar.

As for why I need so much power, I want to see if a 45' RV can pop a wheelie.


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## Lordwacky (Jan 28, 2009)

for the nearly $1 mil price tag I would think you could build a Fuel cell powered RV and maybe a nice Wind/solar powered hydrogen generator to fuel it. Kinda like the buses Ballard is building for the Vancouver olympics.

Let the Hydrogen trashing begin......


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## Drew (Jul 26, 2009)

TheAtomicAss said:


> I figured on the weight, it's the physical size that I'm still trying to shoe-horn into my design. I've got 45'x8.5'=382sq. ft. of space, so the batteries would have to be about 2' above the bottom of the chassis, completely front to back. Which is why I'm hoping SE comes out with higher-capacity cells that are physically more power-dense, sometime before I begin construction.
> 
> As for charging, I had intended to setup the charger to run off anything from a single 2-phase 240V 50A connection, all the way up to 2 separate, 480V 100A 3-phase connections. Oh, and the roof will be completely covered with solar.
> 
> As for why I need so much power, I want to see if a 45' RV can pop a wheelie.


How have you dealt with the weight? I can't think of any vehicle aside from a B double which can carry over 35 Tons


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## TheAtomicAss (Feb 19, 2009)

Drew said:


> How have you dealt with the weight? I can't think of any vehicle aside from a B double which can carry over 35 Tons


Simple. Don't convert an existing vehicle, and build ground-up to handle the weight.

Really, I'm going to run into DOT issues long before I run into frame strength issues.


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## TheAtomicAss (Feb 19, 2009)

Lordwacky said:


> for the nearly $1 mil price tag I would think you could build a Fuel cell powered RV and maybe a nice Wind/solar powered hydrogen generator to fuel it. Kinda like the buses Ballard is building for the Vancouver olympics.
> 
> Let the Hydrogen trashing begin......


Boo, Hydrogen boo!

Aside from not having the power on tap that the batteries would give me, (and I have my doubts that I can stress a smaller LiFePo4 pack in a manner similar to the Prius' NiMH pack), Hydrogen requires more energy to make it available than can be had back from it, in essence making it useless.


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## Drew (Jul 26, 2009)

TheAtomicAss said:


> Simple. Don't convert an existing vehicle, and build ground-up to handle the weight.
> 
> Really, I'm going to run into DOT issues long before I run into frame strength issues.



I think you might run into DOT issues faster than you think. I'm not familiar with American DOT regulations, but if they're anything like Australian ones then you're mass limited by axle configuration.

Specifically, in Australia you're only allowed 16.5 tons for a twin axle dual tyre (8 tyres) axle set, and 6.5 tons for a single steer axle. I know America allows a little bit more for steer axles and I'm not sure about the rest, but I'm thinking at this point that its unlikely they'd allow over double what Australia would for any axle combination and I'd guess that a vehicle capable of hauling over 50 Tons Payload would probably be in the ballpark of say 80 Tons its self. Even allowing for the largest permitted axle configurations over here the most mass you can carry on a vehicle without a trailer is approx 34 Tons without applying for a special permit etc etc. and this is with a twin steer front axle and a triple rear axle, I'm not sure you're allowed to run a triple drive axle though.

I'm not trying to shoot down your plan, but make sure you're abreast of all of the maximum axle limits for heavy vehicles, because it would be extremely disappointing to build a monster like that and end up having it banned from the road.


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## TheAtomicAss (Feb 19, 2009)

Drew said:


> I'm not trying to shoot down your plan, but make sure you're abreast of all of the maximum axle limits for heavy vehicles, because it would be extremely disappointing to build a monster like that and end up having it banned from the road.


Being in violation of DOT regulations wouldn't stop me from taking it on the road, I'd just make sure my surface-to-surface missile launcher was working before taking off. 

*TheAtomicAss is insane


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## TheAtomicAss (Feb 19, 2009)

In all seriousness, however, I think I may reduce it from 2,250 cells to 1,350 cells. At least for my current numbers. This gives me a lot more wiggle room as far as weight and space concerns.


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## Amberwolf (May 29, 2009)

Wont' that make it harder to power the particle beam long enough?
________
buttsex Webcams


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## Woodsmith (Jun 5, 2008)

Maybe he has found a source of crystaline dilithium batteries?


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## kixGas (May 2, 2008)

while this is all very entertaining I still don't see how you could legally drive this. Isn't the max gross weight allowable somewhere in the 80,000 lb range?


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## TheAtomicAss (Feb 19, 2009)

Woodsmith said:


> Maybe he has found a source of crystaline dilithium batteries?


Oh don't think I don't wish.


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## TheAtomicAss (Feb 19, 2009)

kixGas said:


> while this is all very entertaining I still don't see how you could legally drive this. Isn't the max gross weight allowable somewhere in the 80,000 lb range?


Why's everything gotta be legal?


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## Drew (Jul 26, 2009)

TheAtomicAss said:


> Why's everything gotta be legal?



Well, somebody might want you to drive onto a weighbridge at some point 

In all seriousness though, there are other options as well, you could build a battery trailer or something like that?


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## TheAtomicAss (Feb 19, 2009)

Drew said:


> Well, somebody might want you to drive onto a weighbridge at some point
> 
> In all seriousness though, there are other options as well, you could build a battery trailer or something like that?


I wonder if RV's are even required to hit weigh stations at all... I was under the impression it was for commercial vehicles.

I'm hoping to keep it all in one vehicle for maneuverability. Did I mention it's going to have all-wheel steering?


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## TheSGC (Nov 15, 2007)

TheAtomicAss said:


> I wonder if RV's are even required to hit weigh stations at all... I was under the impression it was for commercial vehicles.
> 
> I'm hoping to keep it all in one vehicle for maneuverability. Did I mention it's going to have all-wheel steering?


If it rolls on Spheres, that would just make my day.


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## TheAtomicAss (Feb 19, 2009)

TheSGC said:


> If it rolls on Spheres, that would just make my day.


*ZING*

Right over my head.


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## TheSGC (Nov 15, 2007)

TheAtomicAss said:


> *ZING*
> 
> Right over my head.



http://www.supercars.net/cars/2945.html

If I ever make a custom EV, it will run on spheres. I just have to make a electric sphere motor type system... hmmm to the drawing board.....


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## TheAtomicAss (Feb 19, 2009)

TheSGC said:


> http://www.supercars.net/cars/2945.html
> 
> If I ever make a custom EV, it will run on spheres. I just have to make a electric sphere motor type system... hmmm to the drawing board.....


Ehm... No. I'll be using wheels, thank you.


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## Lordwacky (Jan 28, 2009)

TheAtomicAss said:


> Boo, Hydrogen boo!
> 
> Aside from not having the power on tap that the batteries would give me, (and I have my doubts that I can stress a smaller LiFePo4 pack in a manner similar to the Prius' NiMH pack), Hydrogen requires more energy to make it available than can be had back from it, in essence making it useless.


You are correct Hydrogen is "energy negative" in the sense that it must first be created before it can be consumed. But this is true for any fuel not just Hydrogen, you just don't have to "pay the bill" for the creation of fossil fuels and electricity in the same way. All fuels are victims to the laws of thermodynamics, not just Hydrogen.

This is why I mentioned a Wind/ solar powered Hydrogen generator. You can use an "energy negative fuel" and still be green and/or energy independent (depending on what you are going for). Solar/Wind power H2 generators are currently be used effectively. Fuel cells are far from perfect and you would have challenges, you would likely need to have a battery or ultra capacitor bank to draw extra power from when needed essentially making the vehicle a hydrogen/electric hybrid. Hydrogen Fuel busses have been in operation for a while now, I think Berkley has had one running for like 10 years.


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## TheAtomicAss (Feb 19, 2009)

Efficiency is going to be a big deal for me. I will have the facilities to recharge the pack from the grid, but it's something I'd prefer to avoid whenever I'm not stressing the range.

Which leaves me to solar for the most part. I'd like to get the maximum amount of efficiency out of the solar array as possible, and going solar -> battery -> motor is the most efficient way possible. Wind is not really applicable because this RV will have no fixed point of return. (I intend it to be my solitary residence)


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