Electric vehicle travels record-breaking 623 miles on a single charge

Why do I feel so underwhelmed at hearing that it was done on a track at a measly 25mph?

Why not put the thing on the road in normal traffic and see what it does? Oh, I forgot - to control the record-setting conditions so it's repeatable. OK, now it makes sense. Whatever.

Real reason is cause if it got into accident it would go off like a nuke.

It would be interesting to know the mileage for the top legal speed of 70mph. This mileage should be improved. I will not buy a car based on the 25mph mileage. Just repeat the experiment but this time floor it.

With 8000 batteries is there any space left in the boot for groceries? Also how long does it take to charge and how much electricity does it consume in the process?

this is proof of concept. not to be taken that you should buy one or expect these in the market within a decade.

Homo SUVus is online today I see. Fortunately a low reproductive rate as young women are far more sensible.

this is proof of concept. not to be taken that you should buy one or expect these in the market within a decade.

Scientific and technological advancement is moving ahead exponentially. Ten years would probably be in the ball-park if this technology was moving ahead linearly. But notice how they doubled their record in only six months. They'll likely double this new record in another six months. With this in mind, it is more likely that in only two or three years battery, fuel-cell and other related technologies will have progressed far, far ahead of today making electric cars very practical.

Nanotechnology and the discoveries being made there have placed us right on the cusp of an explosion in technological advancement that will influence almost every field of science. Hold on to your hats.

Perhaps they wanted to drive slow enough to jump out in case the batteries caught fire?

Seriously though.. Sanyo started producing the 18650 battery in 1994 - surely after 16 years the technolgy has improved. I've read a number of articles indicating significant improvements over the last 5 years or so. I wonder why they stuck with 16-year old technology.

http://jp.sanyo.c...-1e.html

The objective is to LEARN, not to make a marketable product.

25 mph is about what the people in Europe and many Asian countries will see most of the time, considering they live in densely populated urban centers. Here in the States, however, you would need to repeat this test at least at 60 mph and that distance better be over 350 miles on a charge or not many people will find it practical.

@SteveL
18650 is just the physical size of the cell(18mmx65mm). Other companies produce 18650 cells. All 18650 cells do not have the same performance. Just because the cells are in the same form factor as older cells doesn't mean they have the same performance.

Does it escape everyone that this is a group of Hobbyists, and that they have essentially doubled the best effort of any auto manufacturer for all-electric car?
What does that say about the auto industry? I don't know, precisely- but it's not good.

@Caliban,

They essentially created a battery-on-wheels, and drove it under totally unrealistic conditions. One has to wonder what the weight and handling characteristics of the vehicle are like...

On top of it all, wanna bet whether the AC/heater was on, whether this thing has more than one speed, whether there was any room left for any passengers other than the driver, or whether there was any room left in the trunk?

On top of that, consider that they went through a 0%->100%->0% charge-discharge cycle. Under such cycling, most lithium batteries don't last more than a couple hundred cycles. Practical EVs only cycle in the range of 40%60% or so to make the battery last the lifetime of the car, so take that 623.76 mile range, divide by 5, and what do you get?

Now let's add up the cost of 8,320 laptop-size lithium ion batteries...

@PE

All of that is given. My point being that with all the resources available to the auto manufacturers, their best efforts to date have remained underwhelming, at best.

Too much for one manufacturer, you say? Why not pool resources, then, and make an all-out effort to get the tech on the ground, and unify a few(practical) standards along the way. We're not talking DVD vs BluRay here.

Sometimes cooperation is the way forward, and competition must take a back seat. Pun intended.

Power-plant Analysis by www.NoFixNoPay.info:

The Daihatsu Mira is one of the lightest four-seat passenger cars in the world weighing just 580 kg (1,279 lb)
http://en.wikiped...tsu_Mira

Mira EV batteries:
(45.5 Grams x 8320) = 379 kG (835 lb) of batteries vs original combustion engine/transmission/petrol tank/radiator/fluids & lead acid battery.
http://www.campso...ell.aspx

Battery configuration:
8320 batteries at 3.7v each provide a 240.5v-294Ah system.
http://sanyo.com/...4-1.html

65 cells in series would provide 240.5v (65 x 3.7v cells) and 333 cranking Amps w/128 parallel banks (128 x 2.6Ah).

25mph Mira uses ~11 Amps for 27 hours w/294Ah limit.
50mph & ~30 Amps for ~10 hrs, Mira EV goes ~500 miles.
100mph & ~100 Amps for ~3 hrs, Mira EV goes ~300 miles.

8320 cells costs ~U$D 40,000 and ~273k Watt/Hr recharge, or 400Amp, 1Ø, 240v charging station for 3 hrs
http://18650batte...battery/

A couple of things...

First, the discharge rate is non-linear, particularly when the battery is at less than 10% of its maximum charge (the discharge rate drops off toward 0 in a smooth curve.)

http://www.mpower...ance.htm

Second, a doubling of velocity increases the power required to maintain that velocity by a factor of 8:

http://en.wikiped...s)#Power

(this ignores parasitic losses from transmission, ball bearings, tires, etc. and only considers air friction; but let's assume all sources of friction scale similarly)

So if Mira used ~2.6 KW (11 A * 240.5 V) to maintain 25 mph, then it would need ~21.2 KW (88 A * 240.5 V) to maintain 50 mph, and ~169 KW (704 A * 240.5 V) to maintain 100 mph (lasting less than 2 hours in the latter case.)

Correction:

lasting less than 2 hours in the latter case

Was meant to say less than 1/2 hour.

And now your job is to compare the technique of the two posters...heh

And unless you build a shatload of Nuclear Reactors to charge said cars, "global warming" will increase, as will oil use to charge them. Oh, wait, we're using THAT oil to make ethanol for cars.

$40k to go 25mph? What use is it?

still waiting on electropneumatic hybrids

@bugmenot23 The only benefit from reaching peak oil is that carbon production is in decline too. i.e we can only produce less carbon from now on as we have less fuel to burn everyday.

@Roj and PE. Thanks. Very useful numbers there.

a doubling of velocity increases the power required to maintain that velocity by a factor of 8

Nice source on battery performance and Drag physics.

The factor is less than 8 using gears, which allow acceleration with no increase in torque or horsepower. When shifting up, the force at the wheels will be reduced, and drag physics will continue to increase, until drag becomes equal to the force at the wheels.

"Some DC motor-equipped drag racer EVs, have simple two-speed transmissions to improve top speed.[53]"
http://en.wikiped...tric_car

375 volt "Killa-Cycle" set a 169mph record in Sept.2009
http://nedra.com/...ers.html

@bugmenot23 The only benefit from reaching peak oil is that carbon production is in decline too. i.e we can only produce less carbon from now on as we have less fuel to burn everyday.

And then they'll jsut start mining coal in greater amounts.

Your thought process is flawed.

@Roj

Gears don't enter the equation since we're looking at speed instead of acceleration. Air resistance follows the formula Fd = ½*p*v^2 *Cd*A where p is the density of air, Cd*A is the drag coefficient and drag area, and v is the velocity.

To calculate power, we multiply Fd with the velocity, which means that the drag equation becomes Pd = ½*p*v^3*Cd*A and it is easy to see that doubling the velocity increases the power by a factor of 8. Proof: 1^3=1 and 2^3=8

Furthermore, you have to add the rolling resistance of the wheels which is independent of velocity. Again, Pr = Fr*v

If you simplify the constants and sum the two together, you get P=Av + Bv^3 where A represents the properties of the wheels, and B represents the properties of the vehicle travelling through air.

So in fact, when you double the speed, the power required to move the car is increased more than 8 fold. Acceleration without increasing power is impossible anywhere else but in frictionless vacuum.

@Roj

Gears don't enter the equation since we're looking at speed instead of acceleration. Air resistance follows the formula ½pv^2CdA where p is the density of air, CdA is the drag coefficient and drag area, and v is the velocity.

To calculate power, we multiply force by velocity, which means that the drag equation becomes ½pv^3CdA and it is easy to see that doubling the velocity increases the power by a factor of 8.

Furthermore, you have to add the rolling resistance force of the wheels. If you simplify the constants and sum the two together, you get Av + Bv^3 where A represents the properties of the wheels, and B represents the properties of the vehicle travelling through air.

So in fact, when you double the speed, the power required to move the car is increased more than 8 fold. Acceleration without increasing power is impossible anywhere else but in frictionless vacuum.

To: Roj

Gears don't enter the equation since we're looking at speed instead of acceleration. The drag force increases in the second power of velocity. To calculate power, we multiply force by velocity, which means that the drag power increases in the third power of velocity. That is, double the speed, multiply power by 8.

Furthermore, you have to add the rolling resistance force of the wheels. If you simplify the constants and sum the two together, you get Av + Bv^3 where A represents the properties of the wheels, and B represents the properties of the vehicle travelling through air.

So in fact, when you double the speed, the power required to move the car is increased more than 8 fold. Gaining velocity without increasing power is impossible anywhere else but in frictionless vacuum.

Sorry for the triple posting. The system threw XML errors at me and I assumed it didn't go through because of the formulas.

There's a world of difference between an electric car designed to maintain 25 mph, and one designed to go up to 70 mph in real traffic.

Here the gearing comes into play. The efficiency of an electric motor is greatly diminished when it runs at less than 20% of its rated speed, and it is almost zero at standstill.

With designs that employ only a single reduction gear to avoid a gearbox, the car designed for highway speeds gets poor efficiency at up to 15 mph. Regenerative braking also works poorly and the drain to run the more powerful motor control electronics dominates the energy budget at low speeds. (you can think of it like the "idling" consumption of an engine.)

These kind of effects are the reason why cars like this will go 600 miles on a battery which would propel an ordinary passenger vehicle just 100 miles or less. Everything is a compromise because the battery costs and weighs so much.

This is a great example of new technologies being pushed but it seems to me batteries alone are not ready for the prime time. plug in Series hybrid tech is the way to go with microturbine or deisel generators for long trips and batteries for short ones are clearly the perfect stepping stone. but its great to see people pushing the boundaries.