Perhaps
400 miles if you live in sunny southern California but I don't you'd see anything close to 400 miles if you live in northern CA, or any place where they get snow or it gets cold. The pie-in-the-sky claims are for the tree huggers.
Elon Musk's Earth-bound transport company has upgraded its two-seater Roadster sports car design with a better battery – and a new body that will increase the range of the flash motors by up to 50 per cent, apparently. "Battery technology has continued a steady improvement in recent years, as has our experience in optimizing …
"why a BATTERY operated car needs sunshine..."
It needs sunshine to keep the driver warm and on a limp along at < 50mph to demonstrate impractical range claim run it probably needs sunshine to keep the battery warm.
400 miles will probably take around 9 hours which is averaging a bit less than 8kW to flatten a 70 kWh battery. If you need 2kW to warm the driver your 400 mile range is shot to hell.
To further your point about warming the battery, depending on the battery design operating the vehicle with the battery temp at ~27C vs. 20C nets ~10% more power from a typical battery. When temps get down near the 10C range battery output drops as much as 25% compared to 20C. So operating in warm temps vs. cool or cold temps, can yield a dramatic difference in battery performance alone. If the vehicle is operated any place other than on flat, smooth roadways, power consumption increases and range decreases.
Does it really matter whether it's 300 miles or 400 miles? or less, the average journey in the UK at least is less than 20 miles (average being the operative word). If you are fortunate enough to be able to afford two cars, then one that can do 80-90% of your journeys for virtually free (excepting cost of car and depreciation and excluding the discussion on whether the environmental cost of creating and transporting and recycling the battery in the first place is environmentally sustainable) would seem to be an advantage.
Personally I think hydrogen is the way to go as the output from the exhaust is water and hydrogen would appear to be a lot more plentiful than some of the exotic elements that batteries are being made of.
Yes it does matter. The point of announcing an increase from 245 => 400 mile range is to convince people to buy these cars. If in fact as many have suggested the numbers are bogus or only under ideal conditions then people are being deceived and or defrauded.
All the other issues about vehicle cost, battery recycling, etc. are secondary to the central theme of increased range. It's also worth noting that electricity is not free and the price is increasing in many areas.
Hydrogen fuel cells may prove to be a better choice. Time will tell.
For the clueless... An EV doesn't need sunshine, it needs warm weather to cut parasitic losses, to eliminate the use of an electric powered cabin heater, to eliminate the use of electric windshield wipers, etc. Flat roads in warm Southern California reduce power usage vs. Northern California or any hilly country. Operating these EVs in any environment other than an ideal flat, warm, dry environment lowers range dramatically. Thus it's laughable to claim 400 mile range when you're likely to get half of that in most less than ideal operating environments, especially cold, snowy areas.
Of course if you had a CLUE you'd already understand this.
> Of course if you had a CLUE you'd already understand this.
Careful with the arrogance, Mr. (ahem) "BornToWin".
> Thus it's laughable to claim 400 mile range when you're likely to get half of that in most less than ideal operating environments
From reading the article, it does not look like the 400 mile estimate is an official figure, but more of a working number, or simply a guess. In any case, one does not know what the test conditions are (if you do know, please share), or how effective range varies with any deviation from those, although you do seem to have a pretty good idea, judging from your assertion that you're "likely to get half" and that a 400 mile range is "laughable". Care to enlighten us on your calculations, please?
I would also like to point out that the correlation between amount of sunshine, temperature, and air density is not a simple one: one must at a minimum bring in latitude, time of the year, and altitude into the equation as well.
Lastly, a hilly ride is not necessarily a fuel-inefficient one in modern cars (electric or not). For one thing, on mountain roads one tends to drive at a slower speed than on motorways (if intending to stay on the road), with the reduced drag offsetting somewhat the extra thrust required when moving uphill. At the same time, the downhill parts of the ride result in nil or negative fuel expenditure as power may not be required from the battery to keep the car moving (in modern internal combustion engines, injection is cut off during overruns), and it may instead be recovered from the descent (regenerative braking, which for example my non-electric car has).
In short, too many factors and unknowns for one to be able to draw any firm conclusions.
While you make some valid points, the primary point here is that pie-in-the-sky claims of "up to 400 miles or almost double previous mileage claims of 250 miles", are a fantasy, disingenuous and designed to dupe naïve, gullible consumers who have not a clue about how EVs function in the real world. The intent is to deceive, plain and simple.
FWIW, the point about sunshine is only relevant in the frame work of ambient temp to keep the battery/passengers/driveline warm enough to get the most battery performance, the least parasitic losses and eliminate the need to provide warmth (or air-conditioning) to the vehicle occupants - all of which lower range significantly. (The sunshine is not being used to recharge the batteries, though it's an inefficient option for some applications.)
Unfortunately with hilly terrain, the power to ascend is always greater than the power recovery on descent due to parasitic losses in the driveline in both directions. In addition there is never even close to 100% recovery of available power on descent, so it's always a net loss over flat, warm terrain. For the most part EVs are useful for city driving. Delivery trucks could also use electric propulsion but the fact is electricity is not free nor are the cost of EVs practical or cost effective in comparison to conventional vehicles. Maintenance costs and disposal costs for toxic waste batteries, etc. also come into play in the total cost of ownership operation.
Until these shortcomings are resolved, few people will buy EVs but all in society will pay for the infrastructure to support these impractical devices via all sorts of taxes and unfair credits to those who buy these impractical devices. You are paying right now and you don't even know it... Maybe THAT is what society should focus on instead of a fantasy 400 mile range?
And you've tested the original roadster and found that it's range was lacking in what circumstance exactly?
245 is about the range you get - VERY cold (or VERY hot) weather will impact that, but hills are gravitational batteries, not perfect ones, but pretty good - they don't cost nearly what you think they will when you stop converting brake discs to dust on the descent and refill the tank instead. The battery conditioning systems are pretty sophisticated, and whilst they do draw power they improve the power efficiency of the battery pack by more than enough to compensate...
> Do you think they'd mind me burning 100 miles of range running a pair of 15" speakers linked to the throttle position
As you may know, the road to an all-electric sports car is littered with the failures of all those who came before Tesla. I distinctly recall (probably from a Register article¹) that one of those hopefuls intended to do exactly that, as they believed that a "silent" sports car would be an unattractive proposition.
¹ Guessing it must have been, as I remember a reader commenting to the effect of hacking the sound system to replace the default sporty engine roar with that of a Citroën 2CV.
Electric cars will not become popular until all manufacturers agree to design their cars around a specific battery ISO. This will allow them all to design a car whose fuel cells are swappable, allowing them to be made fuel use of in the places where they are most desirable:
Cities.
Swappable batteries will make the cars easily recharged and infinitely more profiatble that the sale of oil fuelled cars as the batteries lose consistency every day eventually needing replacement after so many years or parts therof.
Accredited battery sharing clauses will make refuelling with new batteries mandatory and as profitable as the market will allow.
"Accredited battery sharing clauses will make refuelling with new batteries mandatory and as profitable as the market will allow."
Swapping batteries is technically feasible, the problem is that it won't work if the asset ownership transfers at every battery change - think of the nature of the second hand car market, and you'll see that you'd have perennial problems of companies and car owners trying to swap duff battery packs onto unsuspecting mugs, and seeking only to ever take back prime condition packs.
A battery leasing model might be the way forward. The lease company owns the asset and provides it fully charged, the customer pays for energy metered out of the battery plus the costs of swapping and asset depreciation. Battery ageing is a minimal problem because as a driver you're never landed with a duff battery that you own, and because the battery leasing company can monitor the asset condition and life expectancy of every battery, withdrawing packs as they age.
The problems with this are that there will be limited competition in the battery leasing market. Even if you have multiple leasors, a battery swap station will only carry a few brands. It will also be a natural business evolution for business leasing (ie financial services) companies, so given the inherently crooked nature of financial services I would expect unfair T&C, penalties for "exiting" one leasing scheme to join another, punitive costs for wear and tear or accident damage, restrictions on self charging, and anything else that the bankers can invent to line their pocket at the expense of the consumer.
However, given the limitations and losses in battery EVs, I can't help concluding that EVs will remain a metropolitan solution. A more practical universal "low emissions" transport solution would be power-to-gas systems using H2 dissociation and methanation to produce methane, which most spark ignition engines could easily run on. End to end efficiency is poor, but that's true of EV's outside of the laboratory, but methane powered transport is fully compatible with anerobic digestion of degradable wastes, with fossil natural gas solution, and potential future resources like gas hydrates.
If battery swapping isn't something the average non-technical person can do easily and safely, then it won't be viable. Even the technically challenged can place a petrol nozzle in the fuel tank but I can imagine the nightmares trying to change batteries weighing hundreds of pounds or more. Charging to swap batteries just like quick charging is viable if EV owners are willing to pay for this. Then the issue is where are these stations located and are they on a route near where you desire to travel. If not then it's not practical to drive your EV on that destination. It's worth noting that the populace should not be paying for these infrastructures or services any more than we should pay for petrol stations.
" It's worth noting that the populace should not be paying for these infrastructures or services any more than we should pay for petrol stations."
Why not? The populace might not want to, but that's immaterial. The only thing you can suggest they "should" be paying is the operating costs, and a fair rate of return on capital employed (including commercial risk).
Tax payers did not pay for petrol stations, companies who felt they could profit from selling crude oil products did. The same should hold true for electric vehicles. If these machines are deemed viable then utility companies or independent stores will build recharging stations to supply electricity for commuters who buy these cars. This way the people buying the electric cars are paying for their energy just as people who drive petrol or diesel cars pay for fuel, i.e. their "energy". Why should those who drive petrol or diesel powered vehicles pay for the fuel and recharging sites for electric vehicle owners? That's irrational and unfair. If you disagree then perhaps you wouldn't mind paying my petrol bills?
Quite. Lots of people claiming the mileage claim is cobblers, yet I have read of quite a number of S drivers in very cold countries who are very pleased with the range performance. I will remain hopeful until tests show it one way or another.
Cold weather also reduces the range of ICE cars as well btw. It really isn't an easy thing to quantify. http://www.fueleconomy.gov/feg/coldweather.shtml
Given that a Merc E-Class Coupe and the new Merc C-Class claim to have a drag coefficient of 0.24, and are both quite tall cars which you would not normally associate with low drag, how come this Tesla Roadster only has a drag coefficient of 0.31? Are Mercedes massaging their numbers, or has Tesla (aka Lotus) turned a low-slung aesthetically pleasing sports car into a brick in the wind tunnel? You'd have thought that where range matters, they'd be using as slippery a shape as possible, not just improving battery & reducing rolling resistance. According to wiki, the Saab 92 from 1949 has a better Cd (0.30) than a 2014 Tesla Roadster!
Well, primarily because (if the photo's accurate) even with the new version they've simply stuck with the formula of shoving a battery and a motor in a Lotus Elise, which is fundamentally a twenty year old design conceived for a power to weight ratio of 200 hp/tonne. Why mess around spending thousands more hours in the wind tunnel when that would make no material difference to the handling or acceleration?
Regarding the contributors to the 0.31 cd, at a semi-educated guess, it's because aerodynamically challenging essentials such as wheels and wheelarches, windscreen wipers, doorhandles, cabin air intakes, wing mirrors etc are proportionately a smaller contributor to the overall drag of larger vehicles. With an Elise based body design you've got a very small car, and unless you can magic away the lumpy bits designed around the size of a human, then you'll struggle to make a road legal smaller car have a materially improved cd. If there were a free lunch from improved aerodynamics, then car companies would have been onto it some years ago simply to improve fuel economy to meet CAFE or to gain a marketing advantage.
My semi-educated guess is that it's probably a tradeoff between aerodynamic efficiency and generating downforce (and therefore also drag) for stability and better handling at speed. A typical Formula One car would have a Cd of 0.7 to 1.1 (ref. Wikipedia) depending on what downforce they need for a particular course; obviously they're not very fuel efficient. Tesla's 2012 and newer Model S has a drag coefficient of 0.24, so I doubt the Roadster's size is the problem. I bet most of the design is very aerodynamic but it has features to create downforce at the right locations that are causing some of the drag. (Also see this list of 10 production vehicles with low drag, which says of the list, "You may notice that very few high-performance vehicles make the list. The reason? Most supercars are preoccupied with downforce and therefore utilise large wings, spoilers and other aero elements to reduce lift at high speed. This, of course, results in more drag.")