Chinese Automaker BYD Rolls Out Massive Electric Car
Vehicle uses "iron-based" battery to get 200 miles between charges
Charles J. Murray, senior technical editor -- Design News, January 12, 2010
DETROIT - Chinese automaker BYD Auto today rolled out a massive electric vehicle today that uses an "iron-based" battery to go more than 200 miles on a charge.Known as the E6, the new vehicle will be marketed as a family-oriented crossover having roughly the same exterior dimensions as a typical family car. Weighing in at 5,060 lb, the new EV is 179 inches long and 64 inches high, making it significantly larger than most of the electric vehicles introduced to date. BYD introduced the E6, which is expected to be marketed in the U.S. later this year, at the North American International Auto Show (NAIAS) here.
The E6 departs from previous EVs, not only in its size, but in its use of the company's so-called "Fe" battery. BYD officials at the show declined to describe the battery specifically other than to say that it is "iron-based," but it is believed to use a lithium iron-phosphate chemistry. A spokesman for the company said the battery's cost is approximately one-third that of lithium-ion batteries being used in competing EVs and its energy density is about 90 percent of that of lithium-ion. BYD officials said they are able to build the battery for low cost because BYD is "the biggest battery company in the world."
Because the E6 is so large, it uses a battery pack weighing "more than 400 kg" (880 lb), BYD officials say. (Experts at the show suggested that the battery pack could weigh significantly more than 400 kg). "Yes, it's bigger," said Paul Lin, a BYD spokesman. "But it costs less and is safer than lithium-ion. That's what's important."
BYD's E6 electric crossover vehicle weighs more than 5,000 lb and goes 205 miles on a charge.
Talkback
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Bottom line is...how much $.
Daniel Garrett - 2010-3-2 15:53:27 EST -
Torque isn't a single number. It is measured as a function of RPM.
Internal combustion engines have very low torque at idle and usually peak at about 3500 RPM. That's why a transmission is needed - to multiply the torque to start the car rolling.
Most electric motors have a more or less flat torque curve from zero to maximum rpm. They don't need a multi-speed transmission but they still use a final drive reduction gear to multiply the torque.
As I understand it piston steam engines produce maximum torque at zero rpm and the torque curve approaches zero as the rpm climbs.
Mike Harrigan - 2010-18-1 18:00:08 EST -
@Phil et al,
Exactly, EVs are not intended or expected to tow trailers etc. For now EVs are ideal commuters and runabouts. An ideal commuter or 2nd car for many families.
Malcolm Faed - 2010-18-1 10:22:17 EST -
Asynchronous motors and permanent magnet motors cannot produce very high torque. The maximum is about from 1.5 to 2.5 times the rated torque. Electric motors with controllable winding in both stator and rotor, that is, DC commutator motors and wound rotor synchronous motors can produce for a short time (thermal limit!) much more, about from 3 to 5 times the rated torque.
The maximum torque is limited also by the power electronics feeding the current to the motor.
For these reasons you usually need a gearbox for an electric motor if you need high torque at wheels. Naturally a two stage gearbox may be enough to give required torque for steep hills with a trailer.
Jouko Niiranen - 2010-15-1 06:57:15 EST -
Steam vz Electric? Any railroader (or wannabe) knows the old saw that a steam engine can pull a train it cannot start where a Diesel (i.e., an electric loco with a Diesel generator) can start a train it cannot pull. it follows, as has been stated, that starting torque on steam engine is nil, while all the torque on an electric motor is at 0 RPM.
Bob Sexton - 2010-14-1 16:34:46 EST
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