GM Volt 1.4 ICE Range Extender

[rgathright]

Originally Posted by NeilBlanchard

The other reason I have heard for why they did the Volt this way, is to force you to always plug it in when you can. It makes just enough as it goes along, and then you will plug it in to get a more efficient energy source.

Good idea.

Engineer the car to drive slower once the battery pack gets low. You would encourage people to charge up more often at the same time reduce gas consumption by FORCING responsible driving habits.

I guess this means that the chances of a cel-phone wearing, redneck Volt driver cutting you off in a highway construction zone is going to be rather slim. Ha!

[gone-ot]

Originally Posted by rgathright

Good idea.

Engineer the car to drive slower once the battery pack gets low. You would encourage people to charge up more often at the same time reduce gas consumption by FORCING responsible driving habits.

...should get really interesting just about the moment you start up and onto the freeway "on" ramp!

[rgathright]

Originally Posted by Old Tele man

...should get really interesting just about the moment you start up and onto the freeway "on" ramp!

No, in this case you would be looking to get on the freeway using a "down" ramp.

[cfg83]

Hello -

I thought this was interesting :

2011 Chevrolet Volt - Chevy Electric Midsize Sedan - Automobile Magazine

(Page 3) ... In Sport mode, the electric motor turns the front wheels with 149 horsepower through a single-speed gear reducer (versus 121 horsepower in the Regular mode). The 71-horsepower engine doesn't match that so the battery is allowed to drain a bit below the normal minimal state of charge threshold to assist. When regen is available, that 'borrowed' charge is restored. However, the battery is never fully replenished during driving because it's cheaper and greener to draw that power from the electrical grid by plugging in the charger. In pursuit of a 10-year, 150,000 mile service life, the strategy is to treat the 400 or so lithium-ion cells with kid gloves. That means charging the battery only after it's heated to room temperature by a system that circulates warm anti-freeze through its confines. Also, only half of the battery's full 16 kilowatts of energy is ever intentionally used. While GM has not specified the exact limits, the guess is that the state of the charge is never allowed to drop below 30 percent or rise above 80-percent in the interests of battery longevity.

Does the Prius or Insight try to keep the batteries warm during recharging?

CarloSW2

[RobertSmalls]

The 2000 Insight simply refuses to charge its batteries very hard when they're very cold. Regen starts to fall off when it's below freezing out, and at 10°F, I have almost none. Assist is also reduced with temperature, and at -20°F the 12V starter gets used. The Volt has lithium ion batteries instead of my NiMH, but I imagine they'll be all but useless in frigid weather.

[rmay635703]

What I don't get is why they need a 1.4ltr on a series hybrid.

The whole purpose of a series hybrid is to use a taylored high efficiency SINGLE SPEED motor to drive your genny. Like the 60mpg military turbine generator powered humvy we all got our panties in a bind about several years ago. You can easily gain 25% by setting a motor up to be tuned for one speed.

Also to me that would mean a 1ltr NON TURBO should be sufficient to maintain 65mph. (And I doubt GM would have any trouble finding a 1ltr engine, it seems many here still drive one with a GMish badge on it.)

Your goal of coarse would be to fire up the motor to the ideal operating speed REGARDLESS of vehicle speed once the generator charges the batteries a predetermined ideal amount (depends on how long the motor takes to get "ideal") Then shut down and cycle on and off as needed while the vehicle motors along. Sort of like pulse and glide, allows the motor to only operate in its most efficient band.

[NeilBlanchard]

That is one way to set up a serial hybrid, but Chevy has not done it that way -- they vary the ICE RPM's to adjust to the required power, and they do not charge the battery with the ICE. The reason they do this (they say) is to force you to recharge it when you get to a plug.

I'm not sure this is the right choice, overall -- but I'm sure it depends on how much you drive it each day. I think that since they had to do parts bin engineering, and used the 1.4L to begin with, they may have made the best choice for this design...

[cfg83]

NeilBlanchard -

Originally Posted by NeilBlanchard

That is one way to set up a serial hybrid, but Chevy has not done it that way -- they vary the ICE RPM's to adjust to the required power, and they do not charge the battery with the ICE. The reason they do this (they say) is to force you to recharge it when you get to a plug.

I'm not sure this is the right choice, overall -- but I'm sure it depends on how much you drive it each day. I think that since they had to do parts bin engineering, and used the 1.4L to begin with, they may have made the best choice for this design...

I agree. We know a 1.0 turbo was in the running. I don't have the URL, but I *thought* a non-turbo 1.0 was also considered (but maybe the 1.0 was always a turbo).

At then end of the day they went with the 1.4. The latest Prius is up to a 1.8 @ 3000 lbs curb weight. A Volt with a 1.4 @ 3500 lbs curb weight is "reasonable" to me.

CarloSW2

[rmay635703]

Originally Posted by NeilBlanchard

That is one way to set up a serial hybrid, but Chevy has not done it that way -- they vary the ICE RPM's to adjust to the required power, and they do not charge the battery with the ICE. The reason they do this (they say) is to force you to recharge it when you get to a plug.

I'm not sure this is the right choice, overall -- but I'm sure it depends on how much you drive it each day. I think that since they had to do parts bin engineering, and used the 1.4L to begin with, they may have made the best choice for this design...

Sounds to me that they were actually just being lazy as that requires less R&D to determine optimal operation and discharge/recharge intervals.

Any motor, even their stock 1.4l has an ideal power output, keeping the motor there as much as possible is always better than the nearly 50% variation in efficiency when you run the gamut from idle to WOT.

This brings up a point, since the motor is decoupled seems that an ECU reprogram or a manual control of the ice could allow future owners to improve the ICE mode operation of their volt.

[99LeCouch]

If it works and is affordable to us, then great!