Posted by *drydem* on August 21, 2008, 11:54 am

Cobasys makes NiMh batteries for vehicles

http://www.cobasys.com/products/transportation.shtml

And their current production ready car battery system

the Series 1000 [1] would require alot of batties to run

a single car. Each 12V (8Ah) battery is 2.4kg - it has

a nominal energy of 108 Wh. Basically you get 45wh

per kilogram of battery. How heavy would a battery

system be for an electric car? Suppose an engineer

was tasked to design a battery system for a 2 ton

EV which had a top sustainable speed of about

60 mph for 4 hours straight without refueling?. How

big would the battery system be? Is such a

design criteria be unrealistic?

[1]

http://www.cobasys.com/pdf/transportation/Series1000Brochure.pdf

Posted by *Cydrome Leader* on August 21, 2008, 3:16 pm

*> Cobasys makes NiMh batteries for vehicles*

*> http://www.cobasys.com/products/transportation.shtml *

*> And their current production ready car battery system*

*> the Series 1000 [1] would require alot of batties to run*

*> a single car. Each 12V (8Ah) battery is 2.4kg - it has*

*> a nominal energy of 108 Wh. Basically you get 45wh*

*> per kilogram of battery. How heavy would a battery*

*> system be for an electric car? Suppose an engineer*

*> was tasked to design a battery system for a 2 ton*

*> EV which had a top sustainable speed of about*

*> 60 mph for 4 hours straight without refueling?. How*

*> big would the battery system be? Is such a*

probably over 2 tons for the batteries alone, that's part of the problem

with electric vehicles that aren't forklifts circling around at 6mph in a

warehouse 1000 feet from a charger.

Posted by *BobG* on August 21, 2008, 3:43 pm

*> Each 12V (8Ah) battery is 2.4kg - it has*

*> a nominal energy of 108 Wh. Basically you get 45wh*

*> per kilogram of battery. How heavy would a battery*

*> system be for an electric car? Suppose an engineer*

*> was tasked to design a battery system for a 2 ton*

*> EV which had a top sustainable speed of about*

*> 60 mph for 4 hours straight without refueling?. How*

*> big would the battery system be? Is such a*

*> design criteria be unrealistic?*

==========================

=======================

Lets say you can cruise at 60 using 30hp... about 25KW... lets use 2

hrs instead of 4... you'll need a 50KW battery pack... thats about 460

of those 12c 108 whr batts...1111kgs...2400lbs

Posted by *Cydrome Leader* on August 21, 2008, 6:01 pm

*>> Each 12V (8Ah) battery is 2.4kg - it has*

*>> a nominal energy of 108 Wh. Basically you get 45wh*

*>> per kilogram of battery. ?How heavy would a battery*

*>> system be for an electric car? Suppose an engineer*

*>> was tasked to design a battery system for a 2 ton*

*>> EV which had a top sustainable speed of about*

*>> 60 mph for 4 hours straight without refueling?. How*

*>> big would the battery system be? ?Is such a*

*>> design criteria be unrealistic?*

*> ================================================*

*> Lets say you can cruise at 60 using 30hp... about 25KW... lets use 2*

*> hrs instead of 4... you'll need a 50KW battery pack... thats about 460*

*> of those 12c 108 whr batts...1111kgs...2400lbs*

The old VW beetles had about 30HP engines, struggled on highways and

that's without the 2400 pound battery pack.

Posted by *Eeyore* on August 24, 2008, 12:14 am

BobG wrote:

*> > Each 12V (8Ah) battery is 2.4kg - it has*

*> > a nominal energy of 108 Wh. Basically you get 45wh*

*> > per kilogram of battery. How heavy would a battery*

*> > system be for an electric car? Suppose an engineer*

*> > was tasked to design a battery system for a 2 ton*

*> > EV which had a top sustainable speed of about*

*> > 60 mph for 4 hours straight without refueling?. How*

*> > big would the battery system be? Is such a*

*> > design criteria be unrealistic?*

*> ================================================*

*> Lets say you can cruise at 60 using 30hp... about 25KW... lets use 2*

*> hrs instead of 4... you'll need a 50KW battery pack... thats about 460*

*> of those 12c 108 whr batts...1111kgs...2400lbs*

You're thinking pure EV with a decent range.

My numbers assumed a stupid commute only EV or PHEV. Still 2/3 of an

imperial ton or about 3/4 of a short US ton.

Graham

> Cobasys makes NiMh batteries for vehicles> http://www.cobasys.com/products/transportation.shtml> And their current production ready car battery system> the Series 1000 [1] would require alot of batties to run> a single car. Each 12V (8Ah) battery is 2.4kg - it has> a nominal energy of 108 Wh. Basically you get 45wh> per kilogram of battery. How heavy would a battery> system be for an electric car? Suppose an engineer> was tasked to design a battery system for a 2 ton> EV which had a top sustainable speed of about> 60 mph for 4 hours straight without refueling?. How> big would the battery system be? Is such a