Comments on: How the Chevy Volt Operates Past the Customer Depletion Point http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-depletion-point/ Real-time news, information, and discussion about the Chevrolet Volt. Fri, 25 May 2012 14:34:00 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Anatole Maher http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-depletion-point/#comment-138137 Anatole Maher Wed, 19 Aug 2009 02:15:05 +0000 http://gm-volt.com/?p=1232#comment-138137 ".. “If you have a propulsion system in which a small efficient gasoline engine powers an onboard generator which in turn supplies electrical energy to an electric motor to propel the car at 50 mpg, why would you not employ this system as a mainline powerplant without the expensive batteries?.." That same thought occurred to me' I would assume the 50 mpg is obtained by recovering regeneration energy during deceleration which would otherwise be dissipated as heat when braking a car with straight ICE drive and transmission They have to store this regeneration energy somewhere, hence the battery the minus side of course is the expensive battery which weighs 400 lbs and occupies space, and battery maintenance which is still an unknown factor. How many persons could afford/would purchase a car transporting 4 persons for 40 thousand dollars? “.. “If you have a propulsion system in which a small efficient gasoline engine powers an onboard generator which in turn supplies electrical energy to an electric motor to propel the car at 50 mpg, why would you not employ this system as a mainline powerplant without the expensive batteries?..”

That same thought occurred to me’
I would assume the 50 mpg is obtained by recovering regeneration energy during deceleration which would otherwise be dissipated as heat when braking a car with straight ICE drive and transmission
They have to store this regeneration energy somewhere, hence the battery
the minus side of course is the expensive battery which weighs 400 lbs and occupies space, and battery maintenance which is still an unknown factor.
How many persons could afford/would purchase a car transporting 4 persons for 40 thousand dollars?

]]> By: Anatole Maher http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-depletion-point/#comment-138130 Anatole Maher Wed, 19 Aug 2009 01:48:26 +0000 http://gm-volt.com/?p=1232#comment-138130 "..since a HPhr of energy generated by the ICE costs about 3 times as much as a HPhr of energy drawn from the battery, you want to run the ICE as little as possible.." I am addressing only this part of your comment. How did you arrive at this conclusion? Here in Jacksonville Fl regular gasoline with about 10 percent alcohol retails for $2.60 I estimate the energy content about 35 kwh per gallon of the mixture (I may not be accurate, if so, please correct 0.9 gal regular gasoline = 0.9 x 125,000 =112,500 BTU 0.1 gal ethanol = 0.1 x 84,000 = 8,400 BTU Total energy content of mixture =120,900 BTU =35.4 kwH GM says it uses a 1 litre turbo charged gasoline engine, I don't know its efficiency, let's assume 0.30 also a generator eff of 0.92 Combined eff = 0.28 output = 9.8 kwH per gallon of mixture @ $2.60 Cost per kwH from the ICE = 26.6 cents I paid 12.83 cents per kwH on my last bill, the ratio is about 2:1 As an aside, an article in our local paper quoted MrHenderson ceo of GM as stating that "the cost of charging the Volt is about 40 cents a day at 5 cents per kwH" That's for 8 kwH driving 40 miles. 1 cent a mile!!!! I assume Mr Henderson has solar panels on his roof or GM pays his electric bill. “..since a HPhr of energy generated by the ICE costs about 3 times as much as a HPhr of energy drawn from the battery, you want to run the ICE as little as possible..”

I am addressing only this part of your comment. How did you arrive at this conclusion?
Here in Jacksonville Fl regular gasoline with about 10 percent alcohol retails for $2.60 I estimate the energy content about 35 kwh per gallon of the mixture (I may not be accurate, if so, please correct
0.9 gal regular gasoline = 0.9 x 125,000 =112,500 BTU
0.1 gal ethanol = 0.1 x 84,000 = 8,400 BTU
Total energy content of mixture =120,900 BTU =35.4 kwH
GM says it uses a 1 litre turbo charged gasoline engine, I don’t know its efficiency, let’s assume 0.30 also a generator eff of 0.92
Combined eff = 0.28
output = 9.8 kwH per gallon of mixture @ $2.60
Cost per kwH from the ICE = 26.6 cents
I paid 12.83 cents per kwH on my last bill, the ratio is about 2:1
As an aside, an article in our local paper quoted MrHenderson ceo of GM as stating that “the cost of charging the Volt is about 40 cents a day at 5 cents per kwH” That’s for 8 kwH driving 40 miles.
1 cent a mile!!!!
I assume Mr Henderson has solar panels on his roof or GM pays his electric bill.

]]> By: Anatole Maher http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-depletion-point/#comment-138117 Anatole Maher Wed, 19 Aug 2009 01:09:39 +0000 http://gm-volt.com/?p=1232#comment-138117 I've been searching for that information also, as well as some spec on the electric motor and drive train. (Asynchronous, 120 kw, 3 phase, frequency controlled? with a reduction gear?) I live in Florida where the temperatures have been over 90F these past few weeks, so I use the A/C every time I step in the car and if I leave it 45 minutes in a parking lot the steering wheel gets too hot to hold. A similar situation, in reverse, would apply to those pore guys who live up north , in those cold dark winter days Half an hour to defrost the windshield..Brrrh! No one in these discussions seems to use air conditioning in the summer or heat in the winter.Have you any idea how much energy those require, presumably from the same battery pack? I’ve been searching for that information also, as well as some spec on the electric motor and drive train. (Asynchronous, 120 kw, 3 phase, frequency controlled? with a reduction gear?)
I live in Florida where the temperatures have been over 90F these past few weeks, so I use the A/C every time I step in the car and if I leave it 45 minutes in a parking lot the steering wheel gets too hot to hold. A similar situation, in reverse, would apply to those pore guys who live up north , in those cold dark winter days Half an hour to defrost the windshield..Brrrh!
No one in these discussions seems to use air conditioning in the summer or heat in the winter.Have you any idea how much energy those require, presumably from the same battery pack?

]]> By: Anatole Maher http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-depletion-point/#comment-138114 Anatole Maher Wed, 19 Aug 2009 00:54:34 +0000 http://gm-volt.com/?p=1232#comment-138114 From the article cited, GM claims the energy consumption for 40 miles in the 'electric mode' assume city driving is half the battery capacity, or 8 kwH I drive an old Honda Civic, 1.5 llire gasoline engine with AT, estimate around 24 mpg city driving using regular gasoline (no alchohol) Checking some data which I;ve long forgotten that works out to around 36 +kwH /24 miles or roughtly 1.5 kwH/mile or 60 kwH for 40 miles GM specs give the mechanical transmission efficiency at around 0.89 , (45 kW electrical in/40 kW mechanical out) which would correspond to a vehicle energy consumption of 7.1 kwH Is it possible the efficiency of my vehicle is only 7.1/60 or 12 percent? I imagine that the control system somehow maintains a constant rpm of the engine/generator combination by reducing the fuel input when the demand drops. How does that affect engine efficiency ?(the statement is that the engine runs at constant speed and maximum efficiency) From the article cited, GM claims the energy consumption for 40 miles in the ‘electric mode’ assume city driving is half the battery capacity, or 8 kwH
I drive an old Honda Civic, 1.5 llire gasoline engine with AT, estimate around 24 mpg city driving using regular gasoline (no alchohol) Checking some data which I;ve long forgotten that works out to around 36 +kwH /24 miles or roughtly 1.5 kwH/mile or 60 kwH for 40 miles
GM specs give the mechanical transmission efficiency at around 0.89 , (45 kW electrical in/40 kW mechanical out) which would correspond to a vehicle energy consumption of 7.1 kwH
Is it possible the efficiency of my vehicle is only 7.1/60 or 12 percent?
I imagine that the control system somehow maintains a constant rpm of the engine/generator combination by reducing the fuel input when the demand drops. How does that affect engine efficiency ?(the statement is that the engine runs at constant speed and maximum efficiency)

]]> By: Anatole Maher http://gm-volt.com/2008/08/25/what-happens-in-the-chevy-volt-past-the-customer-depletion-point/#comment-138103 Anatole Maher Wed, 19 Aug 2009 00:34:40 +0000 http://gm-volt.com/?p=1232#comment-138103 What happened to the road resistance and air resistance at 70 mph? What happened to the road resistance and air resistance at 70 mph?

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