# New Electric Car



## evmetro (Apr 9, 2012)

That is a lot of ah. I can go 100 mph with my 200 ah pack, but 14000 ah may be a bit too heavy.


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## Skywalkerkenobi (Aug 24, 2013)

I calculate that the batteries will weigh about 430 KG. 

Is this too much?


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## Duncan (Dec 8, 2008)

Hi Skywalker

14400 ah
That is an odd number!
Are you sure it is not 14400 mAh?

You will also need to tell us about the voltage

Volts x Ah = Watthours - this is the energy - depending on the car it will take 200 - 300 watthours to go one mile

430Kg of lithium batteries will be about 40Kwatthours - 130 miles range
430 Kg of lead acid will get you around the block


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## Skywalkerkenobi (Aug 24, 2013)

I am sure it is 14400 ah.

The voltage for each battery is 3.2 V


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## Duncan (Dec 8, 2008)

Skywalkerkenobi said:


> I am sure it is 14400 ah.
> 
> The voltage for each battery is 3.2 V


very good
now how many batteries do you have?


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## Skywalkerkenobi (Aug 24, 2013)

There will be 72 batteries in total. Each one is 200 ah and weighs about 5.70kgs.

Also, is this motor good? Will it be enough for a VW golf?

AC 3Xx2-26.26
Dual Shaft


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## ishiwgao (May 5, 2011)

Skywalkerkenobi said:


> There will be 72 batteries in total. Each one is 200 ah and weighs about 5.70kgs.


The mystery of 14400ah is solved!

I'm guessing you double multiplied your batteries, e.g. 72 x 3.2 = 230V, and then 72 x 200 = 14400Ah. You don't multiply Ah together unless you're connecting them in parallel.


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## Skywalkerkenobi (Aug 24, 2013)

So is the motor good? 

Or is the warp 9 or 11 better??

You can find my requirement in my original post.

Also, new question, is a BMS Necessary??


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## evmetro (Apr 9, 2012)

The motor is good. Some will say you don't need a bms, some will say you do. I would say you do. Your pack btw, is 115 volts, 400ah, and 46kwh,


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## Skywalkerkenobi (Aug 24, 2013)

So the AC 3Xx2-26.26 Dual Shaft can get a golf to 100 miles an hour?

Also, at 55-60 miles an hour, how fast will this motor consume all 14400 ah?

What range will I approximately get (If I never stop and the terrain completely smooth.)?

Thanks for your support!


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## evmetro (Apr 9, 2012)

I have hever heard of aj electric car with 14000 ah. Earlier you said that you were going to use 72 200ah cells that were 3.2 volts each. To use a 35x2 double motor with 72 cells, you will be wiring 36 groups of two parallel cells into a string of 36 cells to get 115vdc each group of two cells will be 400 ah. To see how many ah your pack will be, multiply 115 vdc times 400ah. I was once new to building EVs and understand the confusion, so if you need further help with understanding how many ah you will have, let me know and I can further clarify.


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## Skywalkerkenobi (Aug 24, 2013)

72 X 200ah batteries is 14400 ah right?


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## mk4gti (May 6, 2011)

nahh, it's still 200ah, unless you plan on using the car at 3.2V


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## Skywalkerkenobi (Aug 24, 2013)

But I only 144 volts for the motor.

72 batteries X 3.2 volts is 230.4 volts. That is too much!!

What do I do?


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## mk4gti (May 6, 2011)

buy less batteries


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## Duncan (Dec 8, 2008)

Skywalkerkenobi said:


> But I only 144 volts for the motor.
> 
> 72 batteries X 3.2 volts is 230.4 volts. That is too much!!
> 
> What do I do?


72 x 3.2 = 230v 

You can have 230v and 200Ah
Single string all cells in series
Or 
two strings of 36 x 3.2 = 115v
115v and 400Ah
Two strings of 36 cells in parallel (2 x 200 = 400Ah)

Or you can use a DC motor - (Warp 9/11 or ex forklift) and a Soliton Controller that will use 230v and drop it to a lower voltage for the motor


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## Skywalkerkenobi (Aug 24, 2013)

But more batteries give me a longer range!


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## Skywalkerkenobi (Aug 24, 2013)

Duncan said:


> 72 x 3.2 = 230v
> 
> You can have 230v and 200Ah
> Single string all cells in series
> ...


I really want to use a ac motor.

If I use a controller to lower the voltage, am I wasting charge from the batteries????

I think your two string solution might work for me.


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## Duncan (Dec 8, 2008)

Skywalkerkenobi said:


> I really want to use a ac motor.
> 
> If I use a controller to lower the voltage, am I wasting charge from the batteries????
> 
> I think your two string solution might work for me.


_I really want to use a ac motor._
AC is the way of the future BUT at present it is a lot more expensive for the same performance than DC

_If I use a controller to lower the voltage, am I wasting charge from the batteries????_
No 
Controllers are power in = power out devices
At low speed your motor only needs a few volts
Motor - 23v - 1000amps
Battery - 230v - 100amps
23v x 1000amps = 230v x 100amps (the controller does the = step)


_I think your two string solution might work for me._

You can use two separate strings but it is normally better to double the cells up and then couple then into a single string
they are the same thing but the second way copes better with cell variability


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## Skywalkerkenobi (Aug 24, 2013)

http://rebirthauto.com/product-category/ev-marine-hardware/battery-connections/

These are used to double the batteries right???


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## evmetro (Apr 9, 2012)

I would hold off on buying anything until you get a firm grasp on what you are going to build. I would suggest organizing a complete parts list for the entire build before buying anything as well. I was taught by an expert on here to draw an entire schematic of your car., and I thought he was nuts, but it forced me to see the big picture. It sounds like you could really benefit from a few hours of reading about other peoples builds on here, the wiki here, and evalbum. You will be glad you did. If you have questions, keep asking... I know from experience what it is like to be new to EVs, so I will answer everything that I can.


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## Skywalkerkenobi (Aug 24, 2013)

evmetro said:


> I would hold off on buying anything until you get a firm grasp on what you are going to build. I would suggest organizing a complete parts list for the entire build before buying anything as well. I was taught by an expert on here to draw an entire schematic of your car., and I thought he was nuts, but it forced me to see the big picture. It sounds like you could really benefit from a few hours of reading about other peoples builds on here, the wiki here, and evalbum. You will be glad you did. If you have questions, keep asking... I know from experience what it is like to be new to EVs, so I will answer everything that I can.


Is there somewhere that I can find a parts list??


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## EVEngineeer (Apr 11, 2012)

http://www.diyelectriccar.com/forums/showthread.php?t=73869 

here is the parts list


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