Chevy Volt: Advance "Spy" Photos and Article

[Cadillac Jim]

The photos here look like they are really leaks from cell phone cameras, not casual-looking photos from journalism quality SLRs.

http://www.foxnews.com/story/0,2933,414942,00.html

This concept is likely part of our future, along with hybrids, high-mileage daily drivers, and alternative fuels.

[WarrenJ]

Last year I watched a video, probably YouTube, wherein a Chevy/GM suit explained the Volt was almost ready-to-go except for the fact appropriate battery technology had not yet arrived.

If anyone has detailed info on the Volt battery technology, I'd really like to see it. I'm guessing others would also be interested.

Regards,

Warren

[JimD]

I have been reading that Continental Automotive Systems is tooling up to produce lithium - ion cells for the Volt battery packs.

Nothing official though.

[Bruce Nunnally]

Bob Lutz just shared with the press that the battery testing results so far have been flawless.

I am looking forward to this powertrain technology in a Cadillac.

[Cadillac Jim]

Lithium Ion is the technology of choice for automotive applications because of its power per volume and mass, its deep discharge capability, simple battery maintenance (charging techniques and overcharge prevention), and moderate cost. It's Achilles' Heel is its life of 5+ years regardless of use, even when left on the shelf. Its total ability to retain charge decreases slowly with time and somewhere between 5 and 10 years, usually between 5 and 7 years after manufacture, it must be replaced to keep the utility of the laptop/hybrid/electric car. The cost of replacement of a Prius battery is about $2500 and the dealers will tell you that it will need one between 5 and 7 years after purchase.

Since the Prius is otherwise a fine and trouble-free car, I tell my friends to just buy the battery and don't look back, and if anyone rags them about it remind them of the cost of overhauling the transmission of a 5 to 7 year old Chrysler or whatever. But this doesn't seem acceptable to GM, at least until now, with the Volt. GM has been working toward a better battery technology for some years now and there just doesn't seem to be one. All of them have service lives of on the order of 5 years and, for the very large battery in something like a hybrid vehicle, a high replacement cost.

[Bruce Nunnally]

I think the real answer is some sort of capacitive array. Something with an instantaneous recharge rate, and no chemical content. But today's state of the art batteries will work until we get the next generation ready.

[Cadillac Jim]

Huge capacitors have their own issues in physics and technology. Their energy storage in Watt-seconds is (1/2)*C*V^2, which means that a humongous car stereo with a 48 Volt, 1,0000,000 microfarad (1 Farad) power supply capacitor stores 1152 Watt-seconds of energy. Compare that to an ordinary automobile battery with a rated capacity of 200 Ampere-hours. Roughly, this is 200*(3600 seconds/hour)*(12 Volts) = 8,640,000 Watt-seconds, or 100 Watt-days. The capacitor for the humongous car stereo has enough energy to light a 100 Watt bulb for 11.5 seconds.

Think about BTU per pound ratings for various combustible fuels. Batteries store energy chemically, and the BTU per pound ratings give us the potential energy per weight of the fuel. At 125,000 BTU/pound, gasoline has 131,882,000 Watt-seconds per pound of potential energy. Batteries store energy as chemicals in the electrolyte or plates. Capacitors store energy as free or excess electrons in a conductor on one electrode attracted to another electrode with a similar deficit of electrons, separated by an insulating distance. The capacitance is (eps)*Area/Distance where (eps) is the permittivity, and Area is the total area where the electrodes are separated by Distance. The zinger is the value of the permittivity, which is about 8.85 X 10^(-12) Farads per meter. Most capacitors with high capacitance use very, very small distances and large areas, and electrolytic capacitors typically use an oxide passivated layer in a porous or thin foil aluminum or tantalum electrode; this limits the maximum voltage before the insulation breaks down. Thus a one Farad capacitor is huge as electronic components go.

[TDK]

Jims 97 ETC,

I believe you would have been fascinated by the SuperConductor from "Superconductivity Inc" I arranged for our company about 12 or 15 years ago. It used a niobium-wire magnet immersed in liquid helium (at about -445F as I recal) to store 3-gigajoules of DC power in an immense gaussian field. It was charged and discharged (a controlled collaspe of the field) via a industrial variable speed drive/invertor, which in turn spun our 400-hp motor for up to 15-seconds durng total, brief power outages. Very cool technology, (pun intended) but a bit spendy. We were the only industrial users in the world of this technology for perhaps 5-years. We wanted to use it for a "rail gun" just for fun later on.

We replaced it with "flying restart" technology of our own design. With these systems a "soft-start" opens duirng any outage and its senses the rpm of a 4160-volt 400-hp motor and rotating mass as it spins down. When/if the power comes back, all three phases re-engage at a firing rate to equal the current rpm. They then re-accelarate at the same controlled rate of the previous decline. Very smooth and it just works, as opposed to starting across the line and out of phase, (ouch!). Much nicer regular startups as well.

Later,

[Cadillac Jim]

Motor-generator sets with flywheels have been used for many years for computers, both for insulation against irregularities in the power lines and for bridging power interruptions. Secure data installations use them to prevent any possibility that data will be transferred out of the facility through the power lines. Using a supercondicting eletromagnet for the "flywheel" is certainly a unique and fascinating twist.

In recent years these things have been replaced by a switching power supply and a battery maintenance circuit, with a true sine-wave inverter running off the battery. The switching power supply is the motor, the battery is the flywheel, and the inverter is the generator. Very boring, but I have a small one keeping my main home machine and key peripherals going in the face of the occasional power glitch. It cost me $125 about 6 years ago.

[Texas Jim]

In recent years these things have been replaced by a switching power supply and a battery maintenance circuit, with a true sine-wave inverter running off the battery. The switching power supply is the motor, the battery is the flywheel, and the inverter is the generator. Very boring, but I have a small one keeping my main home machine and key peripherals going in the face of the occasional power glitch. It cost me $125 about 6 years ago.

I too, use switching power supplys on my stuff.

I have an APC 1000 UPS for my computer and an APC 1500 UPS for my Sony 60 inch HDTV and the Direct TV sat box.

When my garage caught on fire and power went out in the house, the first indication I had was the APC UPS kicked in and the overhead light went out in the computer room.

Darling Wife was watching TV without a light on and did not know anything was going on. The UPS had taken over and was powering the TV and sat box.