Quote:
Originally Posted by MonaroSS
You don't need some journalist to tell you that if the Volt relies on it's battery for 'dynamic response' which the ICE cannot provide, then it must draw down power out of the battery down below it's charge sustain level. So by definition it must at some point recharge the battery back up to that charge sustain level if it is to avoid a deep discharge (if its not close to home) that may otherwise damage the life of the battery.
The only time that it can avoid that is if it 'knows', as Lutz said and which I also quoted, how far it is from home:
And the most likely time that the ICE would cycle off is when the Volt knows it is close to home and it is better to wait to recharge the whole battery up to full in one go than to add a little recharge up to the charge sustain level.
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From a current thread ('Characteristics of the 1.4l engine'), the gas engine of Volt will deliver 100hp. For this type of car this may be decent as a maximum power output (even when battery is depleted).
I don't think it is wise to assume that a driver of a Volt would like to behave accordingly to Volt's 'will' - When the battery gets to 30% must go home slowly and recharge the battery.
The car may know that is close to home, but the driver may get an urgent call to get fast somewhere 100 miles away. This car should allow him to get decent there.
So, I guess that when the battery is depleted and the car is under stress (driver in a hurry), it should be possible to rev the engine to get those 100 hp or more to power the emotors directly through the generator. Normally the engine would run at optimum rpm deliver less power to the generator.
Also, the 'power of the car' should be limited to this maximum power the gas engine can deliver with or without charged battery. It wouldn't be safe to have the car behave differently depending on the state of the battery. Like making a pass and especting to get 6s to 60mpg, but since the battery is down, this time you get only 12s and best wishes.
And since it's an electric car, people would be glad to get 9s to 60m and 100 mph speed, so no need to conceive complicated and dangerous scenarios for various power outputs of the car.
It may be possible to fit the car with a more powerfull engine for better performance (like the 140 hp version the Curze is getting), but that would mean that either the engine will assist more the batteries, or the batteries would have to deliver more power (more charge-discharge; decreased lifetime). Allowing for more power output means allowing for more agresive driving, which lowers the mpg and the mpg figure is the make it or break it for the car.