Winter operation of GM Volt

Possibly the same way Telsa does.

An electric heater is one of the simplest answers. Does GM have engineers that can get this right...Yes. Does GM have management that can force the wrong answers ....yes. Interesting to see who prevails.

 

Hmm... Interesting question.... have to think about that.

How about run the electric A/C to condense air and the gas engine will provide the warmth?

If both A/C and heater runs on electric, the battery pack in cold temp will not put out enough juice to drive the Volt. It seems starting the gas engine is a must.

 

Well, I drive a FULL EV, and my FULL EV works just like my Prius when in demist mode. It first dehumidifies the air with AC, then passes it to the heater which warms it for the cabin. All this is done with a heat pump system running on nothing but battery. Ever.

Or at least the way the Rav4EV does!

 

The heater is a simple electrical resistance heater.

Tom

 

Rav4EV, as well as any other EV with heat.

While I don't have any solid information, it is almost certain that the GM Volt will use a resistive heater unit. A heat pump unit would fail to efficiently provide heat in real winter conditions, so some sort of backup heater is needed. If you have the resistive unit, in makes sense to use it for defrosting and defogging.

Tom

 

The EV that I'm hoping to get (seems to be on hold right now, but I'm still hoping... knock on wood!) will have an electrical resistance heater and a conventional A/C belt-operated from the electric motor. The A/C won't run while the car is stationary, but that's not a problem for me. Defrost will be by running both the heater and the A/C.

Since the Volt is a make-believe car that GM has no intention of ever building, it does not need a defogger. But if they're saying that it will have only one compressor for both heating and cooling, and no resistance heater, then they definitely need to change their ad campaign and say that the car they're pretending they're going to build will have resistance heating.

My Xebra has no A/C but it does have a powerful aftermarket resistance heater. It heats the car much faster than my Prius. When I lived in Fargo, at 20 below F the car took a good ten or 15 minutes to warm up. A resistance heater would heat a car a lot faster than the Prius manages it. And the LiFePO4 batteries in my Xebra do as well at zero Celsius as they do at 25 C. Not sure how well they'd do in Fargo. But that's a moot point for me because after 30 or 35 years on the northern prairie I couldn't take the cold any more myself. If they ever manage to invent those ultracapacitors, cold will no longer affect electric storage.

I don't know about Li-Ion batteries like in laptops and in the Tesla, but LiFePO4 is much less affected by temperature than are lead batteries, and LiFePO4 is not subject to thermal runaway, like Li-Ion batteries are.

 

Big deal. My Prius gets terrible mileage in the winter relative to mild weather driving. And I live in FL. I can only imagine what my mileage would be in Michigan.

John, you word these questions as if a middle school student aspiring to be an engineer is the sole designer and engineer for the Volt. Do you really think they forgot that moisture buildup on the windshield during the winter can be a problem? And what is so "clever" regarding the Prius's method to remove moisture from the vehicle during the winter by using the A/C combined with the heat??? Automobiles have been doing this since A/C was first installed in automobiles.

And with regards to the battery, you can be rest assured they have memos which needed to be bound describing in intricate detail the pros and cons of any and all available battery types which could be used in the Volt. Although I am not privy to their internal communications, I am confident the Li-Ion was chosen based on availability, cost, safety, reliability, etc. over perhaps dozens of other possible types known.

Many on this board despise GM (and I don't particularly care for their products too) but the fact is they still sell over 13 million automobiles per year worldwide. With so much riding on the Volt, I am sure they have more than a couple of 20 year old baby faced engineers working on the vehicle.

Rick
#4 2006
.

 

One sixty year old engineer, two 20 year old baby faced engineers, and 653 marketing guys.

Tom

 

Chevy could easily use a page from the EV1 book. (or the old Ford book)

Use a heated windshield... Put the heat exactly where it's needed.

 

Hi All,

The long term solution might be a thermo-photovotaic generator. The waste heat would go out through a heat exchanger, like the houshold furnace. The unit could double duty as the prime-mover as well. When the battery and passenger compartment are colde, the electricity for the motor comes from the generator.

A short term solution would be an exhaust/liquid heat exchanger, that heats up coolant that is circulated into the heating system. This would be safer than a exhaust / air heat exchanger.

 

Two complete heat pump systems. The system also employs a variable rate compressor for efficiency. I don't live where there is extreme cold. We only get to the 20's here, but the heater will create more heat than I want. It will also cool at over 110 ambient. All this info is in regard to the Rav4EV as I originally posted. I have no idea what the Volt will do - I just know what's possible.

Hold the phone. No. Abosultely not. There is no resistance heater in the Rav4EV. Nor was there one in the EV1. One of the EV pickups at a kerosene heater. Yup, and EV with an exhaust pipe - just like the new Volt!

No idea where this information came from. I can tell you with certainty that it is wrong. In fact only a few EVs had resistance heat. Way too inefficient compared to a heat pump.

I don't know why it would need to, though I have NO idea what the plans are for the Volt.

Here in CA, I don't claim to live in "real" winter conditions, so can't comment. A heat pump certainly works well below freezing. But likely not well below zero.

And the Rav4EV. The Rav uses full pack voltage of almost 400VDC to clean the windshield. In the worst conditions, you have a totally clear view - edge to edge - in under a minute.

 

Thanks for correcting me Darrell, my mistake.

Tom

 

So you think it's no big deal that a car marketed as an electric car with a range extender, claiming to burn gas only when you have to drive more than 40 miles, so that the commuter never uses any gas, is suddenly a gasoline car that burns gas all the time in winter???

I think that's a very big deal!!! If you just want a car that burns gas efficiently, get a Prius. The appeal of the Volt is precisely that if your daily driving is 40 miles or less, you never need to burn any gasoline. No carbon (if you have renewable electricity), no pollution, and no $$$ going to Saudi Arabia to fund al Qaeda.

Now they're telling us that in winter the Volt will be just another gasoline car, and one that only goes 2/3 as far on a gallon of gas as the Prius does!

You misunderstand the purpose of the Volt program, and the way GM hopes it will save them financially:

They never intended to actually sell the Volt, or even to build a real one. The Volt is an advertising campaign, for a non-existent car, intended to convince the American public that GM is really trying to address energy issues, so that the public will accept a federal bail-out of GM, on the grounds that GM is doing something for the nation, so the nation needs to support them. Then, after the bailout, they can eject on their golden parachutes and let the company crash and burn and all the employees go unemployed while all the bailout money leaves the top executives wealthy enough to satisfy Croesus for life.

It sounds to me as though you are describing a gasoline car. "Thermovoltaic" and "waste heat" suggests you assume there's a gas engine creating waste heat.

The Volt is supposed to be an electric car that only uses a gas engine as a range extender!!!!!!!