36 replies to this topic

[niner]

From the article:

"It's a really nice proof of concept," says Gerbrand Ceder, a materials scientist and battery expert at the Massachusetts Institute of Technology in Cambridge. Making lithium ion batteries capable of holding 10 times the charge of conventional versions still requires a cathode that holds 10 times the charge, too, Ceder says. However, he adds, incorporating a silicon nanowire-based anode could allow batterymakers to reduce the weight and volume of the anode and add more cathode material in its place, which could give lithium batteries a power boost. That could make life a little easier for all of us.

Nice work, but it's totally not here yet. If they could make something even close to 10 times the charge, even double the charge of current Li-ion batteries, which are pretty decent already, and do it at a price people could afford, it would not be suppressed. It couldn't be suppressed. The usual problem with this kind of thing is the cost.

[Mind]

The tough part is moving it from the lab to the factory. So many people see new breakthroughs and then wonder why the products never come to fruition. It's because mass manufacturing is not easy. Sounds easy, but it isn't. I have twice tried to bring a product to market and figuring out the manufacturing end of it was the toughest part. Inventing was the easy part. (The sales part of it was also tough)

[Andy]

Check out the Aptera: http://www.aptera.com/

These guys say it gets 300 mpg and could be sold for 30k.

[Lazarus Long]

I was going to post this too about the Aptera but currently it comes in two modes, 120 mile range per charge or with an on board generator that stretches the range to 300mpg.

http://www.popularme...853.html?page=1

It just happens to be very similar to a design I have been working on too so I am jealous.

[niner]

I have one word regarding the Aptera: Oversteer. I think the handling in this thing is going to be scary.

Comparing the Aptera to a more normal PHEV (e.g. upcoming Prius or Volt)

Aptera: 12000mi/yr / 300mpg = 40 gpy
Normal PHEV: 12000mi/yr / 100mpg = 120 gpy

savings over normal PHEV: 80 gpy; $240-$400/yr. So for this modest fuel (equivalent) savings, you give up... handling, luggage capacity, climate control that actually works, who knows what else? It does look cool though.

[Lazarus Long]

I strongly disagree about the oversteer issue but that is separate from the other concerns you raise. The front wheels have a very positive control and the weight on the rear tire prevents it from fishtailing.

I think the vehicle is definitely overpriced at $30K but the hybrid model does have climate control as well as using solar roof PV to maintain climate control in the pure EV.

This is a daily commuter and there is a considerable luggage area. I drive a Prius now and I look forward to the plug in conversion but that conversion does take a severe toll on luggage with added battery weight and volume.

[Andy]

I have one word regarding the Aptera: Oversteer. I think the handling in this thing is going to be scary.

Comparing the Aptera to a more normal PHEV (e.g. upcoming Prius or Volt)

Aptera: 12000mi/yr / 300mpg = 40 gpy
Normal PHEV: 12000mi/yr / 100mpg = 120 gpy

savings over normal PHEV: 80 gpy; $240-$400/yr. So for this modest fuel (equivalent) savings, you give up... handling, luggage capacity, climate control that actually works, who knows what else? It does look cool though.

Have I been living under a rock? What the hell is a PHEV that gets 100mpg and where can I see one?

Thanks

Edited by Andy, 25 December 2007 - 03:17 PM.

[Lazarus Long]

PHEV = Plug-In Hybrid Electric Vehicle.

They are presently a conversion modification designed on the Toyota Prius. They have been around and under development for about 5 years already. The best of them gets over 180 mpg and there are a few developers principally based in California. Cal Cars is one that comes to mind without Google. If you google PHEV you will get quite a few hits and I will get back with more later.

The new GM Volt is being directly developed to compete with the fact that Toyota has already garnered much of the hybrid market and their Prius already has a PHEV model built and under evaluation, with a probable delivery date within two years for the 2010 model year but may even get to market in 09 with a limited edition if the Volt lives up to GM's promises.

The tech is relatively simple in principle. Basically you have an expanded capacity battery pack and the ability to operate as a NEV (Neighborhood Electric Vehicle) on full electric only with approximately a 30 -50 mile range, combined with grid based recharging as well as fuel based on board and recovery braking power regeneration.

[Lazarus Long]

PHEV Wiki


Cal Cars

Sacramento PHEV Test Program results PDF

Toyota road tests a prototype

PHEV Toyota Prius test drive

GM Volt

[nefastor]

About manufacturing being the issue : I think not.

When I was studying electrical engineering about ten years ago, electrolytic capacitors were the largest capacitors in existence and never exceeded one Farad capacity.

Today, thanks to nanowire-enhanced electrode materials, capacitors the same size hold over a FIVE THOUSAND Farads.

It seems the battery technology described uses a similar principle as the capacitors I'm referring to. If capacitor capacity can be multiplied by 5,000 using nanowires, a tenfold increase in battery capacity based on the same idea seems quite conservative.

One thing scares me, tho. Anyone who's worked with li-ion batteries knows how dangerous they are. They will explode if overcharged or undercharged, spewing toxic chemicals. Ten times more capacity means ten times larger explosions. Accidental short-circuits will be a real problem.

You have to remember energy is energy is energy. If you replace a 300-gallon gas tank with a battery that can provide the same amount of energy, you've just switched one type of potential bomb for another. And while gas tanks can explode when a car has an accident, super-batteries will present dangers of their own.

Nefastor

[Mind]

I was thinking the batteries or ultra-caps could be assembled in small units so that 1,000 of them would be the power source for one vehicle (or something on that order). In this way, if 1 or 2 of them fail, it would be a smaller explosion and the rest of the batteries/ultra-caps would not explode. Simpler said then done, I know, but I figured this would be one way to avoid large explosions.

[nefastor]

I was thinking the batteries or ultra-caps could be assembled in small units so that 1,000 of them would be the power source for one vehicle.

Actually that's the only way to go, they don't make large li-ion cells.

At this point in time the best li-ion cells for vehicle propulsion are made by a123. Their cells are even used to power a dragster bike.

http://www.a123systems.com

Their cells are roughly the size of a D-cell. In order to power a typical family car over, say, a few hundred miles, you will need thousands.

Of course, that means they'll be tightly-packed inside the car, most likely in the shape of fuel tank. There's really no practical way to distribute the cells throughout the car to mitigate the effects of an crash : you'd end-up with too much wiring which, by the way, would short the cells in the event of a crash.

I guess we'll just have to drive safely, hey ?

Nefastor

[Lazarus Long]

I'm impressed Nefastor but I guess I shouldn't be, you are into robotics after all isn't that correct?

It is good to see you here.

You literally took my reply to Mind almost word for word from me except for the part about the cost of sensors on each cell not only being too expensive currently but needing to be subwired to a computer to not only handle the state of change aspect for overall condition but to better manage recharging cycles. I also think hybrids are the way to go to extend battery life now and they do it by keeping the discharge levels below 25%.

Ironically smaller batteries drive up both the battery maintenance and sadly, cost. As Nefastor said this is exactly how it is being done right now in all electric vehicles from the Killacycle to the Tesla electric car.

One thing though Mind about explosive risk, lithium has gotten a lot better but if you dead short them you can still force a reaction and this will always be the case when you are able to concentrate a large amount of power in a small vessel and release it swiftly.

As someone who is building electric vehicles with these, the issue of distributing them through the car is not as crazy as it sounds but it has its drawbacks.

I am building stack packs for my electric bikes that will eventually use LiFePo4 but right now I am building them out of recycled NiCads in the *C* because the cost still hasn't dropped enough IMO.

What is nice is the power output curve on them, not just the lower weight what is bad is the number of recharge cycles is still not cost effective. The other issue is amp/hr's of operation in relation to the total volume (not weight) of the battery pack.

I think ultracaps will be online before lithium is really a lot cheaper because of the base materials and lack of adequate recycling systems. (Not to mention the devaluation of the dollar).

For example a 20 amp/hr 48 volt LiFePo4 battery pack can be delivered to my doorstep from China for around $540.
http://cgi.ebay.com/...I...DS%2BI%2BSS
That drives my electric bike at a constant 35mph for a range of about 20+ miles and recharges in about 3-4 hours from dead. The problem is that if I run the pack dead each time the life expectancy is only about 500 recharge cycles. Do the math (that is $.18 plus per mile not counting vehicle cost & maintenance) and gas at 5$ a gallon is still cheaper in a vehicle of that weight class. BTW to double the range of the vehicle also doubles the cost of the batteries but doesn't double the life expectancy.

The seller of the pack above claims 1000 cycles pf operation so that cuts the cost closer to .$10 a mile but frankly that is still not really competitive and is not based on complete discharges. Field tests don't measure up to manufacturer claims that well on longevity yet and that is why the major auto manufacturers have been using NiCd's in all their hybrids.

At least with a hybrid platform the life expectancy is years longer for them because they are not fully discharged and I am working toward building a small generator to do just that. I am also hoping to have my '05 Prius converted to plug-in capability as soon as the warranty is up.

[niner]

It seems the battery technology described uses a similar principle as the capacitors I'm referring to. If capacitor capacity can be multiplied by 5,000 using nanowires, a tenfold increase in battery capacity based on the same idea seems quite conservative.

One thing scares me, tho. Anyone who's worked with li-ion batteries knows how dangerous they are. They will explode if overcharged or undercharged, spewing toxic chemicals. Ten times more capacity means ten times larger explosions. Accidental short-circuits will be a real problem.

You have to remember energy is energy is energy. If you replace a 300-gallon gas tank with a battery that can provide the same amount of energy, you've just switched one type of potential bomb for another. And while gas tanks can explode when a car has an accident, super-batteries will present dangers of their own.

Batteries and capacitors are pretty different animals. I'm not saying that a tenfold increase in energy density over a conventional LiIon is impossible, but it is certainly not "quite conservative".

Battery explosions are no longer a problem. There are now new chemistries available (Li/iron phosphate? -don't quote me, the data's out there somewhere) that are very stable. By the time these things hit the street I don't think safety will be a problem. At the moment, the big problem is cost. Even now, energy density is only a real problem if you are building a pure EV, as opposed to a hybrid or PHEV.

[Lazarus Long]

The main reason the energy density is non explosive for a LiFePo4 (yes that is the lithium phosphate) is that it *melts down* rather than explodes and some have internal fuse circuits but it is still pretty exciting when it does. Also the fuse circuits are a headache in the vehicles because if one goes out it disables a whole pack.

Anyway that is one, when you are stacking a few hundred of these as you are in electric vehicles that meltdown can also meltdown steel and ignite magnesium and aluminum alloys.

I suspect you are exactly correct about the prospects of an ultracap but that will return us to the problem of energy density release being possibly explosive and even if it can be made reasonably safe it will be a device that can be *hot-wired* to explode on demand. Think Spock and how he was constantly blowing things up with a short circuited phaser.

[nefastor]

I'm impressed Nefastor but I guess I shouldn't be, you are into robotics after all isn't that correct?

It is good to see you here.

Thank you

Yes I'm into robotics but actually I've very recently started making plans for my own fully-electric transportation. That probably explain why we are on the same wavelength here.

I did a few calculations based on existing cells to determine what vehicle configuration would be the most suited to safely carrying large amounts of battery cells. Turns out even a123 cells aren't good enough that you could ditch the internal combustion engine outright in most cases (and I explored everything from a mere two-seater sports car all the way up to a 50-ton high-endurance flatbed truck)

For me, the problem is actually quite important. I haven't owned a car in over ten years because I have a definite hatred of pouring money into the pockets of oil companies, not to mention the Middle East. As I'm lucky enough to be French, I get by very easily using all forms of public transportation... and believe me, not having to maintain, insure and fuel a car, nor having had to buy one in the first place, means I get to keep a lot more cash at the end of the month than my colleagues.

My long term goal however is to have an electric vehicle that could get me anywhere (on Earth). I'd also dedicate an array of solar panels on my home's roof to recharging it so that in the end, my freedom of movement would come to no cost for the environment.

I believe we are not quite there yet, but very soon we should be. There have also been some inspiring developments by French car manufacturer Peugeot, for instance the Quark concept :





I've seen this baby in Paris (it's exposed on the Champs Elysée) : it's a large quad (almost as large as a car) with a fuel cell that powers DC brushless motors in each wheel hub. It's drive-by-wire and all the control electronics are concentrated in the dashboard, which is a removable PDA.

What's interesting here is that the body of the machine contains no mechanical part (no engine nor transmission) : it houses the fuel cell and its fuel tank but could easily by filled with batteries instead. I've taken a large number of close-up pictures with a 7-megapixel camera but they are probably too large for me to post here.

From the look of the suspension and the ground clearance, it should be off-road capable, by the way.

Batteries and capacitors are pretty different animals.

Indeed, but they have something important in common : their capacity and their ability to deliver (and take in) high current are linked to electrode surface area, which can be increased a lot by growing nanotubes on the surface of regular electrodes. It's the same principle as the intestine's vilosities (not sure that's the right word in English) : the intestine may be small, its actual internal surface is several dozen square feet. That's why I think a ten-fold increase is kinda conservative... but then again I'm no chemist.

Nefastor.

[Lazarus Long]

Funny that you mention wanting to build electric. I am working on a few all weather designs but this is one I built last year and I can't wait for better weather to use it.

That is a twin 36 volt dual hub motor set up with a 12A/hr battery pack that is getting replaced this year with 30 a/hr pannier NiCad set.

More on that and solar charging them can be found in this thread.
http://www.imminst.o...mp;#entry179443

I have since quadrupled the size of the amorphous array you will see there.

Attached Files

•  Dual_Motor.jpg   1.03MB   60 downloads

[nefastor]

This is the sportiest electric bike I've ever seen, and the first one with two-wheel drive !

They sell plug-in bikes in France but they are more for urban use (as in : riding to the market to get a kilo of oranges) - no self-respecting biker would be caught dead riding one.

More on that and solar charging them can be found in this thread.
http://www.imminst.o...mp;#entry179443

The link is broken

You're probably aware of it, but for those who are interested and are looking for pointers regarding solar energy, here's a great magazine : Home Power Magazine (It's not limited to solar)

I think many of our world's economic problems (starting with poverty) can be solved through extreme decentralization. If all homes could generate their own electricity from sunlight and wind, and use that to power our cars, there'd be no need for oil, especially foreign oil. And there'd be no oil companies either. In the same line of thought (and for no other reason than unashamed proselytism), I want you to check out this awesome project :

Self-replicating 3D printer

Yeah, someday soon we will not only have free fuel, we'll also be able to make our own cars and spare parts without having to deal with manufacturers and middlemen (and credit card companies).

But I digress. It's great to see electric vehicles making a comeback. After all, the very first cars were mostly plug-ins.

Nefastor.

[niner]

Wow, Laz, that is a nice looking bike! What does it weigh? What kind of range and speed does it have?

[Live Forever]

Funny that you mention wanting to build electric. I am working on a few all weather designs but this is one I built last year and I can't wait for better weather to use it.

That is a twin 36 volt dual hub motor set up with a 12A/hr battery pack that is getting replaced this year with 30 a/hr pannier NiCad set.

More on that and solar charging them can be found in this thread.
http://www.imminst.o...mp;#entry179443

I have since quadrupled the size of the amorphous array you will see there.

Looks cool. Laz!

Have you thought about selling bike mods? (online or locally)

[Lazarus Long]

It weighs 83 pounds with a 36v 12a/h SLA battery pack. It cruises at 25-30 on the flat with a 170 pound rider contributing and can go faster if the rider pushes it.

It is a true hybrid, an HEPV, (Human Electric Powered Vehicle) commonly known as a *moped*

It climbs a 20 degree slope with power and pedal at 10+ mph but does a downhill grade of 5-10 degrees at over 50mph.

I have so far clocked over 70 mph as my fastest speed.

The rear motor is switchable and the front motor provides recovery braking. The top end gear ratio is 4:1 and the bottom end is 14:15. The frame is all aluminum and the front end is a set of gas filled shock absorbing forks.

The range on an 12 a/h SLA pack is only about 15 miles but a 40 a/h LiFePo4 pack could more than triple the range to over 75 miles and maybe 100, at roughly the same weight. However that pack is over a $1000 so I do my testing with SLA (standard lead acid) but I am building a pannier power pack setup for LiFePo4 or NiCd to adapt to the machine later.

BTW Nefastor the link is not broken, the thread is now located in an area only accessible to paying members. I may do something about that later.

The rear hub motor wheel is internally freewheeled and externally on the 5 speed cluster. It also has a switch so I can save power by turning it off at cruise speed. I intend to replace the switch with a speed sensor eventually so it goes on automatically when the speed drops below 15 and goes off when above 20mph. Though I intend that to be programmable.

The fancy fairing in front is both a fender for road spray and where I house the controller and switching deck. Being in the airstream there improves cooling for the controller which is has to be able to handle 100 amp peak surge loads and 10-15 amps continuous load.

[Lazarus Long]

Have you thought about selling bike mods? (online or locally)

Actually I have thought about it. I am interested in developing a design and testing facility locally because if HEPV or other ultralight commuter hybrids can handle conditions here they can operate in over 95% of the nation's and probably the world's markets.

I think access to a few lines of alternative transport could be a valuable dealership in the coming fuel price crisis. There are already quite a few available worldwide but local interest is scant. I live in a relatively rural (isolated) community dominated by 4 wheel drives and soccer mom SUV's.

[Lazarus Long]

Also Nefastor I am glad you noticed the *2* wheel drive aspect. This bike handles better than virtually any I have ever ridden (and that is quite a few). It performs off road on dirt and sand without sliding out, accelerates as fast as a motorcycle off the line and corners like a racing machine at high speed on pavement. It has an incredibly low CG.

In order to get the speeds I am obtaining I use high pressure road tread that mimics a racing tire but I find the extra weight and generally heavier structure is necessary to provide safe operations in the power curve available. If the bike were too much lighter then at the speeds it goes it would risk losing traction. Oh because of the weight I installed a third, disk brake on the real wheel. One lever controls both cantilever brakes simultaneously and the other controls the disk.

This is actually designed as a *street machine* and is not intended for off road operations even though I adapted mountain bike tech to do so.

[nefastor]

The fancy fairing in front is both a fender for road spray and where I house the controller and switching deck. Being in the airstream there improves cooling for the controller

I was actually thinking of asking about it... the shape seemed so weird. My initial thought was that you had salvaged it from another bike, and that the electronics were mounted in the frame (which would have acted as a passive heatsink while also benefitting from the airflow while in motion).

It's funny, I didn't remember you were an engineer. Whether you are or not, you deserve a degree in my book. You've pretty much taken everything into consideration, which is more than I can say about the engineer who put a large, shiny, BLINDING BLUE LED on the power button on the front of my computer display (woe to him).

But I digress...

I agree with you that Lithium batteries are still too expensive, tho unlike you I tend to need much smaller batteries (and in greater number) to power robots and wireless sensors. This has led me on a quest to find cheap LiPo cells. And that quest, my friend, has been successful, so I'm sharing my results with you. First, however, I have to point out that your mileage may vary (pun intended) due to the fact that the Euro is currently stronger than the US Dollar, and that I've explored markets that may be very different in the US.

First, LiPo batteries are slowly but inexorably becoming THE battery technology for R/C aircraft modeling. It's the weight thing, obviously. a123, which I already mentioned, actually has products dedicated to R/C but they are very expensive. However it's very easy to find individual (3.3 / 3.6 volt) flat, naked LiPo cells that can be used to create your own battery. All dimensions are available, from postage stamp to postcard (and obviously thicknesses vary with capacity).

This American vendor has prices a Frenchman will consider cheap.

Second, look for clearance sales on car entertainment systems : I've recently bought a total of 40 Ah (7.2) of battery for around $150 dollars, at an 85% discount : these were external battery packs for now-obsolete portable DVD players. The great thing is, they are prepackaged, with a charge indicator, output regulation AND contain their own charger which you can plug on your car's 12V, so it's a lot more than naked cells.

Naked cells can be combined in series and parallel like any batteries HOWEVER this is serious, potentially harmful business. If you're interested, I can post how to do it safely. If you make your own battery you'll also need to add battery supervision chips to it for safe operation (i.e. avoiding over- and under-charge). A bunch of these chips can be obtained as free engineering samples from companies like Texas Instruments. If you can make a high-current motor controller, you will have no trouble understanding how they work.

In the end, you should be able to get your high-capacity batteries for less money, plus you'll get the freedom to shape them like you want. Me, I would place them AND the electronics inside the wheels, for four reasons :

- The basket area could be used for carrying something useful

- The rotation of the wheels will enhance cooling

- Wiring is simplified

- The wheels become heavier which should help with stability at low speed

Ah, and just for fun, you might want to have a look at this really nifty hybrid car being considered by the US Army. With its wheels retracted, it will fit inside the belly of a V22 or a large helicopter. That wouldn't be possible without the in-hub electric motors and drive-by-wire.

Nefastor

[Lazarus Long]

Thanks Nefastor. I would be very interested in your follow up on this statement:

Naked cells can be combined in series and parallel like any batteries HOWEVER this is serious, potentially harmful business. If you're interested, I can post how to do it safely. If you make your own battery you'll also need to add battery supervision chips to it for safe operation (i.e. avoiding over- and under-charge). A bunch of these chips can be obtained as free engineering samples from companies like Texas Instruments. If you can make a high-current motor controller, you will have no trouble understanding how they work.

On a separate note, the *in the wheel* concept for batteries has both pluses and minuses and the reasons have to do with first creating reliable commutators to transfer current from a moving object to a stationary one but the worst aspect, is the mixed blessing of all that mass as a large flywheel and load on the axle & bearings. There is a very different operating profile between a motor for a train or plane that is continuous at a relatively constant output versus vehicles that must constantly accelerate and decelerate.

The hub motors BTW have the same problem with live load wear and tear on the bearing, rotors, wiring, suspension, etc and that has been one of the real world design limitations for using them on larger vehicles but they do not have as much of a problem with respect to overcoming inertia for acceleration and *stopping* momentum for braking.

Because the motor *is* the flywheel it overcomes inertia easier, the motor's *stator* is stationary as well as the wiring and it's weight is concentrated close to the center of mass for the wheel around the axle, not rotating. Even the mass of the moving rotor and casing are still closer to the center of rotation and because a significant percent of the motor's mass (the internal stator) is not moving, the factor of overcoming centripetal inertia and momentum for acceleration and deceleration are reduced dramatically.

Putting the battery pack as a large disk around the motor creates a very large and heavy flywheel (moment) that can be critically balanced but also induces a very powerful precession vector around the axle that means the axle must be 3 or 4 times heavier and the bearings also need to be proportionally scaled up or just the act of turning might torque bend the axle or burn up the bearings, not to mention the response to road shock. You are not only creating a large flywheel but a massive disk that has a considerable amount of the mass toward the periphery rather than concentrated near the center and this uses a lot of energy to spool up or slow down.

There is also the real world problem of all that current and wiring being exposed to road conditions of potential flood immersion, grit, acids, rain, mud and solvents. I like the stability of hub motors but I doubt we will see them in too many off road military vehicles soon. In the *real world* hub motors have an inverse economy of scale that works well on lighter smaller vehicles than generally on larger ones. I would rather bury the batteries inside the frame like stacks of large flashlights but that is why I want to read your reply to the above request.

The pannier power packs that I am making use the stacking method in horizontal tubes held close to the frame and stacked vertically. They lose neither the upper deck nor the foldable baskets which are still going to be present but folded closed when not in use. I actually am thinking about this particular aspect as the product to sell. Fully integrated power packs with (or without batteries) combined with electronics as kits apart from the motors.

BTW I didn't say it before but I am also thinking of pushing the voltage on the bike to 48v soon and that will change the range to speed equation. Once I have a larger more integrated power supply I will give up some of its range potential to go faster. I think the bike can easily cruise at 40 mph (or more) and that changes the dynamic of its mission profile dramatically. I am even thinking of going to 60v.

[Lazarus Long]

The use of hub motors might change on very large vehicles like tanks and transports but that is a very different issue. Stealth tanks that are noiseless with far less of a heat signature are the wave of the future for that tech but even then I doubt they will use external hub motors because they can't be as well armored. These tanks would be more vulnerable to EMP's which will be entering the tactical array for the 21st century with a vengeance as electronics come to dominant the battlefield. I think the search for shielding electronics to EMP is the big challenge of the moment to make electric motors a part of the 21st century arsenal.

However we will see them in military battlefield robots and possibly in *stealth* off road motorcycles and other *stealth* vehicles. Did I mention that my bike is also nearly silent at those levels of operation?

Another mixed blessing with inattentive drivers.

The use of fuel cell driven electric vehicles is the next wave of stealth tech and will come into play first for battlebots but eventually for all sorts of transport because it removes the thermal signature that makes air to ground, and tank to tank weapons effective for night ops and also because of the dramatic reduction of noise that is a dead giveaway for many military ops.

Fuel cells have it all over batteries until we develop fast charging ultracaps because of the recharge turn around that is a tactical vulnerability of electric tech.

This is also one of the reasons that hybrid fuel electric plug-ins have it all over pure EV's in the real world. Who wants to wait hours to use your discharged vehicle when the need is NOW?

[biknut]

Here's the high lites from a report on a electric scooter called a Vectrix that was in the February issue of Cycle World.

Vectrix is powered by a compact DC electric motor designed and manufactured by Parker Hannifin's SBC division in Milan, italy.
The motor is a brushless 3 phase, 12 pole, 16slot, radial, air gap type, rated at 20 kilowatts and 48 foot-pounds peak torque. 6000 rpm max. Power is provided by a 30 amp/125 volt nickel-metal-hydride battery pack, think Toyota Primus.
It has a rated capacity of 3.7 kilo-watt-hours, good for claimed 40-60 miles between charges. It has a 1.5 kw, on-board charger that plugs into standard 110/120 volt outlet, and claims 80% charge in 2 hours.
Claimed acceleration is 0 to 50 in 6.8 seconds. claimed top speed is 63 mph.

The test rider spent a week commuting on it. 16 mile commute each way.
Tried two different routes. One had a 4 mile grade. Halfway up the hill the HOT BAT Warnings start flashing. Going by the dash's estimated range guage, the 4 mile grade ate up 15 miles of juice.
On a flatter route the 16 mile commute used half of the battery's range, forcing two recharges a day. One at work, and one at home.

At estimated 50 cents a recharge that's a dollar a day to go 32 miles, or 3.1 cents a mile.

Then for comparison the tester compares it to the Kawaski KLR650 he normally rides to work.
KLR650 gets 50 miles per gallon, or 6.2 cents per mile, exactly double. He doesn't say but the KLR650 probably goes 100 mph.

Price of Vectrix $10,999
KLR650 $5349

At a savings of 3.1 cents per mile it takes 183,000 miles to break even. This doesn't take into account cost of oil changes, and tune ups, or in the Vectrix's case new batterys.
Vectrix estimates a battery life of 10 years or 50,000 miles. New battery cost is $4,000.

www.vectrixusa.com

Edited by biknut, 11 March 2008 - 06:00 PM.

[nefastor]

Putting the battery pack as a large disk around the motor creates a very large and heavy flywheel (moment) that can be critically balanced but also induces a very powerful precession vector around the axle that means the axle must be 3 or 4 times heavier and the bearings also need to be proportionally scaled up or just the act of turning might torque bend the axle or burn up the bearings.

Wow, I guess I'm so used to slow-moving vehicles I didn't picture that in my head.

Now, here's an alternative. I'm not sure you've ever seen one (not sure they ever sold those outside my country) but my grandpa owned a Velosolex :



This is a (rather heavy) steel bicycle with a two-stroke engine mounted on the front wheel. I still have it in my basement, for sentimental reasons and also because it's now a valuable collector's item.

The concept is elegantly simple : the engine bloc powers a small rubber wheel. You have a lever that allows you to lower the whole thing so the rubber wheel will connect with the front tire (that's your clutch). It's very reliable : sixty years later people still ride those. You get 200 mpg.

More interestingly, the design has been given a whole new lease on life : in 2006, an electric version appeared :


(more pictures and French info on this site.

I've seen a few running around, they are very nice machines indeed. The concept is unchanged : you can use it like a regular bicycle, but now the motor is in the rear wheel hub.

This is a 36V / 400W design, the battery is Li-ion (located in the frame) and will go roughly 30-40 km on one charge (charges fully in 8 hours). It's mostly used by commuters : one charge gets them to and from work a couple of times or more. The "fake motor" on the front is actually a small trunk.

Given the cost of electricity in France, running cost is 1 euro (1.5 USD) for 1,000 km or roughly 0.30 US cents per mile (but I suspect electricity is cheaper in my country due to the fact it's all-nuclear, all-government controlled, and we have so much we actually sell to neighboring countries).

Oh, and this is a Pininfarina design. The man is a genius with a pencil. Guess it's an Italian thing.

Nefastor