Electric cars face battery of hurdles

[OKIsItJustMe]

http://www.detnews.com/apps/pbcs.dll/article?AID=/20080219/AUTO01/802190349

Tuesday, February 19, 2008

Electric cars face battery of hurdles

Sharon Terlep / The Detroit News

In the rush to deliver an electric car to the masses, General Motors Corp. is finding that the all-important battery might not be the only major hurdle.

The heating and cooling systems, for example, are a challenge because they typically are built to run off a traditional fuel combustion engine. That means new types of air conditioning and heating systems must be built.

GM, in a high-stakes race with Toyota Motor Corp. to turn out an affordable, effective battery-powered car, has found that while the lithium-ion batteries themselves are hitting all the marks on early road tests, a host of other issues are beginning to crop up.

"People tend to believe that if the battery question is solved, everything is solved and the vehicle will work," said Frank Weber, GM's vehicle line executive in charge of the electric car program. "But beyond the battery, the electric vehicle presents challenges that are significant."

...

[nebula]

1. I don't see why heating would be a problem

Portable electric heaters are commonly used in homes, no motor required.
Small and powerful, they run solely on electrical power, no motor required.

[phantom power]

2. It's not a technology problem. It's a supply-chain or product line problem.

Nobody makes battery-powered A/C units, or heaters, or radios, or what-have-you, designed for integration in automobile systems.

It's not that they can't, it's just that nobody does it, because there was no need for it. All this stuff grew around the auto-industry organically, over decades, but now they're trying to take all the modern subsystems, and made a big lateral-move to battery power.

[GliderGuider]

3. How much energy does an electric resistance heater use?

How much is in the battery?

What will the range of the vehicle be on a cold day with the heater running? On a hot day with A/C running? On a cold day with the heater and the stereo running? Gasoline contains an ENORMOUS amount of energy. Batteries, in comparison, do not.

[OKIsItJustMe]

4. From the same article

...

"This is not so much a matter of invention," he said, "as much as it's an application of technology they wouldn't normally do."

[tinrobot]

5. Are electric heaters and AC systems efficient?

If not, I'd imagine they could take a real toll on battery life and range.

But on the positive side, if someone develops super-efficient heating and AC for cars, they can upsize the technology and install it in solar homes as well.

[OKIsItJustMe]

6. Well, there's not a lot of inefficiency in electric heaters

After all, inefficiency in electrical stuff tends to create... heat!

However, my understanding is that GM's EV1 used a "heat pump" for both heating and cooling the passenger compartment. One might guess that the same sort of system would be used in the Chevy Volt (and other EV's.)

[tinrobot]

7. Maybe just use the waste heat from the electronics

The inverters, speed controllers and computer chips in an electric car would probably generate a fair amount of heat. I hear lithium batteries can get pretty hot, too... as evidenced by those exploding laptops.

[gravity]

8. Heat is free from the engine

and the AC is powered by the engine directly. There is so much energy in gasoline, that we take it for granite to power the electrical components of the car.

I think the problem is just getting all the high power electrical components working together without putting too much strain on the battery. It is an engineering problem rather than a technological limitation.

[speedbird]

9. this story is rubbish

any college engineering school
could build an electric car,

with appropriate batteries

[CRF450]

10. Thats the easier part.

The article is really talking about the accessories, mainly a/c and heating, which is a big promblem with building an electric car.

[speedbird]

11. GM is tooting its own horn ...

by exxagerating the difficulties
..............................................
I realize that GM's EV1 may have had
a serious difficulty with battery overheating,
with that said
..............................................

accessory load are a concern, but how much?

a normal car has a 2HP alternator, or less
air conditioning, is how much?
heating, is how much?
power steering, at least in theory, only
needs power at slow vehicle speed

typical headlights,
2X 55 watts, which is not that much

[OKIsItJustMe]

12. Which leaves us with a deep abiding mystery

If it's so easy, and GM's only trying to make it look hard, for some nefarious purpose...

Why aren't other major manufacturers marketing production electric cars?

Hmmm...

[CRF450]

13. As far I know...

It takes a good amount of power to turn an a/c compressor. And it is used right much other than cooling the driver off, such as clearing the fog off the windows using the defroster and taking out the moister. Heating is also another issue. Using simple heating coils would not be very efficient as they use alot of power. I somehow doubt the electric motor could get hot enough to collect heat off of it, and do that in less than a couple minutes. Regular cars get their heat from a heater core, which is basically a radiator that engine coolant flows through. The coolant in gas engines are usually 180 to 190 degrees.

[OKIsItJustMe]

14. Electric heat takes a lot of power, but not because it's inefficient

This is talking about in the home, not in a car, but the same laws of physics apply:

http://www.eere.energy.gov/consumer/your_home/space_heating_cooling/index.cfm/mytopic=12520

Electric Resistance Heating

Electric resistance heating converts nearly 100% of the energy in the electricity to heat. However, most electricity is produced from oil, gas, or coal generators that convert only about 30% of the fuel's energy into electricity. Because of electricity generation and transmission losses, electric heat is often more expensive than heat produced in the home or business using combustion appliances, such as natural gas, propane, and oil furnaces.

If electricity is the only choice, heat pumps are preferable in most climates, as they easily cut electricity use by 50% when compared with electric resistance heating. The exception is in dry climates with either hot or mixed (hot and cold) temperatures (these climates are found in the non-coastal part of California; the southern tip of Nevada; the southwest corner of Utah; southern and western Arizona; southern and eastern New Mexico; the southeast corner of Colorado; and western Texas). For these dry climates, there are so few heating days that the high cost of heating is not economically significant.

...

Remember, as I said, GM's EV1 used a heat pump (for both heating and cooling.)