Electric Cars: Savings on Gas & Electric Bills?

[Vanadium 50]

Conventional taxis probably get only half the makers 'city' mileage because of the stop -tart congested driving.

Tart-congested driving? I bet that depends on the exact neighborhood they go to.

 

[Jimmy Snyder]

I have a Honda Civic Hybrid. There is no plugging in, the battery is charged from the heat of braking. It cost me $3000 more than a similar Civic without hybrid. I doubt that I will recoup the $3000 over the life of the car. As I bought it used, I did not get the govt rebate. I don't know whether the cradle to grave energy usage for the hybrid is more or less than the non-hybrid Civic. I get 43 mpg overall, and I drive mostly on highways. When I stop at a light, the engine turns off. This should be a big advantage for city driving, but I don't much of that. As I understand it, turning off a non-hybrid is a bad idea because it costs more energy to restart it than you save by turning it off.

 

[mgb_phys]

When I stop at a light, the engine turns off. This should be a big advantage for city driving,

VW claim that 25% of city driving in Europe is spent stopped and idling.

As I understand it, turning off a non-hybrid is a bad idea because it costs more energy to restart it than you save by turning it off.

It depends on the engine. A bigger problem is the start motor overheating they are only rated for turning the engine over a few times/day - not every few minutes for an hour.

VW had a system on the Golf (at least in Europe) that used a flywheel to restart the engine in traffic. For various reasons it is only practical on diesels.

The next Masda 3 is going to have a system that can restart a gasoline engine just using combustion. It stops the engine at a particular point in the stroke and then uses a pressurised fuel injector (like on a diesel) to restart the engine without any external power.

 

[EnumaElish]

From what I read, it charges to 85% and allows drainage until 30%. Then the engine takes over.

Wouldn't that cause a "battery memory" problem (at the 30% mark)?

 

[mgb_phys]

Wouldn't that cause a "battery memory" problem (at the 30% mark)?

Memory effect is only a problem for NiCd.

Li-polymor are very fussy about the last 10% of charge to full, I'm guessing the volt decided it was easier to play safe and only charge to 85% than risk shortening the battery life.

Discharging fully under load is also bad for Li-Poly but leaving 30% capacity seems a bit pessimistic. It may be that this is to ensure there is enough power available to cold-crank the ICE - assuming the Volt doesn't have a lead acid battery as well.

 

[Moonbear]

The next Masda 3 is going to have a system that can restart a gasoline engine just using combustion. It stops the engine at a particular point in the stroke and then uses a pressurised fuel injector (like on a diesel) to restart the engine without any external power.

That sounds a bit like an old train steam engine start up.