Category Archives: Tesla Motors

Tesla Roadster

Inside the Tesla Roadster Sport

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Tesla Roadster Sport
Tesla recently announced its Roadster Sport edition. To be succinct, the Sport powers from 0-60 mph in 3.7 seconds (.2 seconds faster than the base model), has a sweet HEMI muscle car like orange and black paint job, Yokohama performance tires, custom suspension, and blacked out rims.

So how do you get more juice out of an electric motor? You can’t add performance headers and intakes or any fun widgets like turbo and superchargers. So Tesla hand wound the wires that wrap around the stator to create more power. The stator is the stationary part of an electric generator or electric motor. The non-stationary part on an electric motor is the rotor. Here is a picture of a traditional rotor (left) and stator (right):
Stator and Rotor

Electromagnet

The stator is an electromagnet (see left), meaning when an electric current passes through it, the rotor is magnetically attracted to spin in a certain direction.  So if you hand spin the wires into the stator, you can pack more wires in, allowing more electrical current to pulse through each segment.  The more powerful current sequentially magnetizes each segment  and spins the attracted rotor faster.  Also, I’m not an electrical engineer so you can correct me in the comments section.

The Tesla Roadster is powered by a 3-phase, 4-pole electric motor, producing a maximum net power of 248 hp (185kW). The Sport Model, with its higher density, hand wound stator produces a maximum of 288 hp (215 kW). Both motors are designed for rotational speeds of up to 14,000rpm, and the regular motor delivers an efficiency of typically 90%, or 80% at peak power.  Couple this with Tesla’s new Powertrain 1.5, and you have one of the meanest electric machines ever produced.

Tesla Roadster Sport

Sources: Wikepedia: Stator, Tesla Motors, Jalopnik

Press Release:

Tesla Motors introduces Roadster Sport

SAN CARLOS, Calif.—(BUSINESS WIRE)—Tesla Motors Inc. began taking orders today for the Roadster Sport, a high-performance sports car based on the world’s leading all-electric, zero-emission vehicle.

The Roadster Sport does 0 to 60 mph in 3.7 seconds, compared with 3.9 seconds for the standard Roadster. It comes with a hand-wound stator and increased winding density for lower resistance and higher peak torque. In addition to Yokohama’s Ultra High Performance tires, the Roadster Sport has improved suspension with adjustable dampers and anti-roll bars that will be tuned to the driver’s preference.

The Roadster Sport starts at $128,500 in the United States and €112,000 (excluding VAT) in Europe. Deliveries begin in late June.

“This car can beat nearly anything in its price class – yet it is twice as efficient as compact hybrid sedans,” said Michael van der Sande, Tesla’s senior vice president of global sales, service and marketing. “If you refuse to compromise on performance or the environment, the Roadster Sport is your only option.”

The Roadster Sport is the first derivative of Tesla’s proprietary, patented powertrain. San Carlos, Calif.-based Tesla plans to begin producing the all-electric, zero-emssion Model S five-passenger sedan in 2011.

Tesla has delivered more than 150 Roadsters to customers, and about 1,100 people are on the waiting list. Customers who haven’t taken delivery may upgrade to the Roadster Sport.

“The Roadster Sport embodies Tesla’s spirit of continuous improvement,” said CEO, Chairman and Product Architect Elon Musk. “The Roadster has been a great success, but no one at this company remains satisfied with the status quo.

Tesla Roadster

OnCars.com Incredibly In-Depth Tesla Roadster Video Review

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After the unfortunate Top Gear review of the Tesla Roadster, I thought I would provide a more in-depth and encouraging review hosted by Emile Bouret of OnCars.com.  This three part review is very informative and really covers all the bases, as Emile describes the Tesla Roadster’s design, experience, and performance. You can watch the videos in high quality at OnCars.com, but it was a bit hard to navigate, some of the links sent me to a Maxima review instead of the next part. So I embedded them below.

2009 Tesla Roadster Part 1: Design

This goes over the exterior of the Tesla Roadster. While the car is based on a lengthened Lotus chassis, the two cars only share the same windshield.  The car’s large front intake provides an aggressive look, and more than enough air for the cooling system.

2009 Tesla Roadster Part 2: Interior & User Experience

Don’t let the title fool you, this is actually really interesting. Emile sits inside the Tesla Roadster and starts the car, which is a very unique, Playstation like experience. He also notes that if a law is passed to make electric cars louder, it should amplify the jet turbine sound of the regenerative braking. I don’t really understand how a car can be too quiet and thus a safety concern, especially when most modern family sedans are nearly silent from over 10 feet away.

2009 Tesla Roadster Part 3: Performance

What can be said that hasn’t been said already. 0-60 in 3.9 seconds, instant full torque, and zero emissions.

Source: OnCars.com

Honda FCX Clarity Hydrogen, Tesla Roadster

Top Gear Reviews Tesla Roadster and Honda FCX Clarity Hydrogen

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I was browsing AutoBlogGreen today and I found out that Top Gear had done a piece on the Tesla Roadster. This was something I had been waiting for for a very long time, because I love the British show and couldn’t wait for their take on the famous electric supercar. Performance wise, the car, fitted with Tesla’s Powertrain 1.5, definitely impressed Jeremy Clarkson, likening the car to broadband motoring in a world of dial-up. However, that was before the car’s battery died after 50 miles of driving. Then they were not impressed by the 16 odd hours it would take them to charge it back up. So they got another Tesla Roadster, which Jeremy managed to overheat (overheated motor, he said, which is odd because the electric motor is just air-cooled for its nominal cooling requirement). To add insult to injury, somehow, the brakes broke on the first one while it was sitting in the garage. So this led the show’s hosts to deem the car impractical for today’s world of driving. Here is the Top Gear: Tesla Roadster Youtube video, which will probably go down soon:

[EDIT: If you want to see Tesla’s side of the story, scroll down to the first comment of this article, by Rachel Konrad, Senior Communications Manager of Tesla Motors. Top Gear’s piece ended up being somewhat of a PR disaster regarding Tesla’s reliability, and hearing another side to the story is helpful.  I won’t make a judgment on what happened because I wasn’t there and I can only write about what was in the video.]

The other host on the show, James May, sparked my curiosity at the end, talking about finding an alternative to the battery electric car and future of motoring. So I found the James’ segment on the Honda FCX Clarity Hydrogen electric car. I have never been a fan of hydrogen cars, because they are about as technologically advanced as spaceships and don’t seem like they will be practical economically. Some say the car, right now, would be priced at $10,000,000. Plus, hydrogen is something Shell can sell you, so of course they will push this on us. But I was impressed by the FCX Clarity Hydrogen, which is really basically just an electric car with a hydrogen powered generator that will extend the range to around 300 miles. So it utilizes the superior efficiency of an electric motor while eliminating the bulk and range limits of batteries.  Also according to the video, hydrogen is about at cheap as gas and the car’s only byproduct is water. Don’t be fooled though, the hydrogen car is very far down the road. Here is the Top Gear: Honda FCX Clarity Hydrogen segment:

Sources: YouTube, Autobloggreen

Tesla Motors

Tesla wants some of that money too.

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With loans to the Big 3 all but signed for, Tesla Motors feels they deserve a piece of the government handout pie. Tesla’s Vice President of Business Development, Diarmuid O’Connell, blogged about how it was a bad idea for the Big Three to get money that had been set aside in the December 2007 Energy Independence and Security Act (EISA), specifically Section 136. Section 136 set up the Advanced Technology Vehicles Loan Program (ATVMLP), and Tesla opposed taking money that was supposed to make cars cleaner and instead use it to just keep the Big Three operating.

Tesla CEO Elon Musk told the Detroit Free Press that if the electric car maker doesn’t get a $350 million loan from the government, then the Model S will be delayed and San Jose plant won’t open. Musk said that with $350 million, Tesla could sell 20,000 electric sedans a year by 2011. “We can’t move forward with that without a major amount of capital,” said Musk. “If we don’t get any government funding, then what we need to do is we need to wait until the capital markets recover, which could be a year or two years from now.”

I sure hope the government does the right thing by helping a company with a proven track record of providing energy efficient vehicles. Sadly, the way things are moving right now, this will probably not happen soon enough.

Sources: Detroit Free Press, Autobloggreen

Tango, Tesla Roadster

Tango vs. Tesla Roadster Drag Race

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I’m not an expert on drag racing jargon (“beat the dial handicap so he lost the competition”??) so here is the commentary from video submitter, jorgbrown:

On Nov 30th, the fastest production electric vehicles in the U.S. went head-to-head. While their first meeting had a number of issues, most notably the underfilled Tango battery pack, and the Tesla’s non-upgraded drivetrain, the 1/4 mile time is quite close and indicative of races to come.

In this race, the Tango got 92.15mph in 14.480 seconds, beating its 14.7 “dial” handicap and thus losing the competition; the Tesla got 101.23mph in 14.666 seconds, slower than its 14.5 “dial” handicap and allowing it to proceed to the next round. (Two rounds later, the Tango’s driver got behind the wheel of the Tesla and also beat its “dial” handicap… and thus lost!)

Tesla Roadster

Tesla’s Refrigerator Sized Cooling Problem

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Electric cars require cooling systems. Not nearly to the extent that a combustion engine vehicle does, but lithium ion batteries get hot. Put your laptop on your lap for an hour and you might start cooking your own thighs. So you can imagine, thousands of lithium ion batteries will require a significant amount of cooling. There are 6,831 lithium-ion batteries in the Tesla Roadster, each about a third bigger than a typical AA battery. They’re linked together in a unique package that incorporates liquid cooling, safety fuses, and sensors that prevent the cells from experiencing what battery engineers like to call “thermal events.” The batteries feed 410 volts to the Roadster’s air-cooled AC induction motor. Here is the AC cooling system, for the cabin and battery pack:

Telsa Roadster AC Cooling System

Martin Eberhard, former CEO of Tesla Motors, is making the claim that the current cooling pump is working overtime, a lot of overtime. In, fact Eberhard stated that the pump for his Tesla Roadster seemed to be on all of the time, which is completely unnecessary after the car has been parked for an hour or so. Now the ESS cooling system is crucial to the life of the battery, but this is ridiculous. So, Martin Eberhard, being the electrical engineer that he is, installed one of those electric meters you see on the sides of houses ahead of his car’s charging station. Then he charged the car up fully, unplugged it for four days, then measured how much power it took to recharge the battery after the car sat, fully charged and cool, for four days. Doing some math, he found the car consumed 1,278 kWh per year, from just sitting there. That is enough to power two big refrigerators. Not only is this significant on your electrical bill, but this drastically reduces the lifespan of the pump.  Eberhard explains in his blog post:

The second question is the life expectancy of the pump. I expect that Tesla used an automotive-grade pump from a good supplier. I am also sure that no other car leaves a pump running 24/7. Consider a typical car designed to run for 200,000 miles at an average speed of 30 mph. Such a car is designed to run for 200,000 / 30 = 6,666 hours. Let’s say the designers want some room for error, and design the water pump for that car to operate for 10,000 hours without failure. 10,000 hours life expectancy would be a good-quality automotive pump.

Now, let’s run that same pump 24/7 instead of the couple of hours per day it would run in our typical car. Running 24/7, that pump will pass 10,000 hours in only 13 months. That’s all – end of life. Just to make it through Tesla’s 3-year warranty, that pump would need to last 26,280 hours without failure. To last just 5 years, the pump would need to run 43,800 hours. Hopefully, Tesla installed a pump rated for at least 50,000 hours of operation without failure, implying an MTBF of at least 70,000 hours, assuming an exponential failure distribution. Does any automotive parts manufacturer even make such a pump?

Tesla also told Eberhard that the new Drivetrain 1.5, that they guarantee to retrofit all the purchased Tesla Roadsters with, will not make any changes to the pump. However, in a recent article from TIME, Elon Musk responded to Eberhard’s cooling pump complaints and also shed some light on the nature of their tumultuous business relationship:

Eberhard, the ousted cofounder, says Musk interfered with the design of the roadster, demanding changes that were costly and led to delays. These included installing electronic door latches, building a lightweight carbon-fiber body and lowering the doorsill by two inches. “It cost us $1.5 million to lower that doorsill,” Eberhard says. “We would have been better off to have a simpler car shipping a year earlier.” Musk says his design changes were not the cause of delays. Eberhard says that despite Tesla’s green-tech credentials, the roadster has a coolant pump that operates even when the car is parked, wasting as much electricity as two refrigerators. Musk says that will be fixed next month. Eberhard also gripes that Musk controls the board of directors, whose members include his brother Kimbal Musk. “I’m very unhappy about what’s happened to my company” under Elon, says Eberhard, who still owns about 3 percent of Tesla. “I think he’s a terrible CEO.” Elon Musk responds that “Martin is the worst individual I’ve ever had the displeasure of working with.” –TIME, An Electric Car Loses Its Juice

While Eberhard does have a legitimate complaint, keep in mind he probably takes some pleasure in publicly criticizing Elon Musk’s Roadster. But in the end, both sides just want to see the Roadster improved, and hopefully the issue can be fixed fairly easily and cheaply.