PDA

View Full Version : OT: Cool Electric Car Build



Doozer
06-17-2009, 01:07 AM
http://etischer.com/awdev/

Just thought it was interesting, and a good conversion.

Enjoy.
--Doozer

gnm109
06-17-2009, 10:41 AM
Nice conversion.

I've often wondered what it costs in real energy to charge up a typical electric car. The people who are in favor of electric cars never talk about the cost of the electricity. Someone, somewhere has to generate it.

I like the idea of an electric car for commuting. I know that it's not free to operate one, though. Nothing is free.

lazlo
06-17-2009, 11:31 AM
Wow, that's a very impressive conversion -- a lot of machine work too :)

Apropos to the motor horsepower discussion, peak horsepower is 2x the continuous hp:

Received my motor today. It's a Siemens liquid cooled 42hp (90hp peak) 3 phase motor. Part No: 1PV5133-4WS20 W11

215 - 380 Volt, 282 Amp RMS (400 peak)
6 pole, 3 Phase AC Induction
67 Kw peak (33 Kw continuous)
3500 - 9700 (13,000 Max) RPM
Weight: 178 lbs

Used on the EV Ford Ranger

barts
06-17-2009, 12:19 PM
Nice conversion.

I've often wondered what it costs in real energy to charge up a typical electric car. The people who are in favor of electric cars never talk about the cost of the electricity. Someone, somewhere has to generate it.

I like the idea of an electric car for commuting. I know that it's not free to operate one, though. Nothing is free.

It's not free, but it turns out that the efficiency of electric cars is pretty good, and electric power is cheap.

Let's see: locally diesel is 2.79/gal. A gallon will produce 10 hp for one hour. A hp is 746 watts...so:

$2.79 1 gal 1 hp $0.37
- * --- * ----- = ------
gal 10 hp-hours .746 KW KW-hr

So electricity is pretty cheap in most areas, compared to liquid fuels.
Now, an electric car does a lot better job not idling at stop lights; many can also capture the braking energy, etc. However, charging batteries isn't perfectly efficient by any means.... also, the folks I know w/ electric cars
(none of them Teslas :-)) end up driving them pretty carefully to maximize range, which not everyone does .

The answer is - it depends. My guess is that you might manage 50% of the cost of driving a Prius, which is pretty good. Of course, if you're fond of long smoky burnouts....

- Bart

lazlo
06-17-2009, 12:26 PM
Now, an electric car does a lot better job not idling at stop lights; many can also capture the braking energy, etc.

This guy is actually running regenerative braking. I wonder how much efficiency he's losing running an AC induction motor though (especially the phase conversion).

Plus, a commercial electric vehicle/hybrid has NiMH or lithium ion batteries -- much higher power density, but I don't know how the charging efficiency compares to the Old School lead-acid batteries this guy is using.

Dragons_fire
06-17-2009, 12:33 PM
In the first picture, it looks like he is charging it at work so it might be free to him!!

aboard_epsilon
06-17-2009, 01:03 PM
clever lad ..he's destined for bigger and better projects, i think you'll be hearing a lot more from him over the years.

such a lot achieved ..and he's so young ..

my hats off to him .

all the best.markj

barts
06-17-2009, 01:27 PM
This guy is actually running regenerative braking. I wonder how much efficiency he's losing running an AC induction motor though (especially the phase conversion).

Plus, a commercial electric vehicle/hybrid has NiMH or lithium ion batteries -- much higher power density, but I don't know how the charging efficiency compares to the Old School lead-acid batteries this guy is using.

Almost all high-end electric cars use AC motors w/ variable speed drives; the efficiencies at low motor speed are much better and often allow the omission of a transmission entirely.

I'm not sure of the difference in charging efficiencies, either....

- Bart

rotate
06-17-2009, 01:59 PM
This is yet another feel good project and not really about saving money or the planet.

My guess is that the payback period for EV conversion is >10 years.

The carbon footprint of the batteries and replacing them every 5-6 years will most likely offset any real CO2 reduction.

The vehicle only does 20miles and it does 0-50mhp in 10 seconds!

If you're really interested in saving money or the planet, buy a small car with a small engine, and use it as little as possible.

Evan
06-17-2009, 02:11 PM
It must be nice to have unlimited funds to build something that is supposed to save money. It doesn't save much else. Nice car but very inefficent to turn an IC engined car into an electric.

Lead acid batteries aren't all that bad from an environmental standpoint. They only contain several different materials all of which are easy to recycle. The latest Valve Regulated Sealed Lead Acid (VRSLA) batteries have really good charge/discharge characteristics. It's what I have on my e-bike. They will maintain around 80% of full charge if left sitting for two years and are rated to withstand at least 200 full discharge cycles. The only thing really lacking is energy density.

quasi
06-17-2009, 02:47 PM
being a Kanadian, I always wonder how these things work in - 30 degree weather, when the batteries are cold, they loose capacity. Then you also need heat for the inside of the vehicle.

aboard_epsilon
06-17-2009, 02:58 PM
The lead from lead acid batteries is recycled ..

99 percent of it, ever produced, is recycled according to this vid.

http://www.youtube.com/watch?v=oJj5iIwF8p4

you could not say that, for a lot of other things .


all the best.markj

John Stevenson
06-17-2009, 03:17 PM
Not had chance to read it all thru but he may be using one of the newer stock fork truck power units.

These have normal 24 v / 36 v battery packs and then use a special inverter to get from 24 / 36 volts to 440 volts 3 phase to power a standard off the shelf 3 phase motor, from there to the hydraulic pump.

They are done this way as the most expensive part of the lift truck is the big DC motor and it's the most unreliable because of the high amperage needed and brush gear etc.

Modern inverter technology means it can control the motor far better than heavy amperage switching circuits and be more reliable.

Some of the more heavier gear has the motor inside a water cooled housing.

.

lazlo
06-17-2009, 03:41 PM
Not had chance to read it all thru but he may be using one of the newer stock fork truck power units.

He's using a water-cooled 3-phase induction motor from the EV Ford Ranger, with a home-brewed 90 HP inverter: he gutted a modular 2 HP VFD and upsized the IGBT's.

Teenage_Machinist
06-17-2009, 05:41 PM
Some of my friends have converted two cars to electric. THe money savings are definately there. These particular cars have range of around 100+ mi and 80 mph top speed.

An issue: Chevron owns the patent to use NIMH batteries in cars. Won't license it if it does not use partially gas power.

andy_b
06-17-2009, 10:01 PM
An issue: Chevron owns the patent to use NIMH batteries in cars. Won't license it if it does not use partially gas power.

that's ridiculous. i don't mean you posting it is, i mean if it's true that Chevron owns such a patent then the US patent rules need an overhaul more than ever.

andy b.

Evan
06-17-2009, 10:12 PM
It's very true. Article here:

http://sefora.org/2009/02/26/nimh-batteries-chevron-patents-and-the-future-of-plug-in-hybrid-cars-2/

lazlo
06-17-2009, 10:26 PM
that's ridiculous. i don't mean you posting it is, i mean if it's true that Chevron owns such a patent then the US patent rules need an overhaul more than ever.

It's actually true, and it's a really ugly story: into order to build the EV-1, GM bought control of a patent for a NiMH battery optimized for automotive use from the inventor, Stan Ovshinsky, in 1994. After the EV-1 debacle, GM agreed to sell their control of the EV batteries to Texaco. Less than a week later, Chevron bought Texaco for $100 billion. Two weeks after that, Chevron sued Toyota and Panasonic, who had been jointly making the EV-95 NiMH battery for the RAV-4, for $30 Million for patent infringement. Toyota and Panasonic are no longer allowed to sell the RAV-4 battery in the 'States.

So no electric car with NiMH batteries can be sold in the United States, for fear of being sued by Chevron.

On the up side, this has caused electric and hybrid manufacturers to skip ahead to Lithium Ion batteries.

Brian H.
06-17-2009, 11:23 PM
Here's an interesting article on some new lead-acid cell technology:

http://mobiledevdesign.com/hardware_news/carbon-foam-lead-acid-batteries-0607/

It seems that the company doing the research is replacing the lead plates inside the battery with a carbon foam structure that has a lead slurry of sorts in it. They claim that these batteries "approach" the energy density of Li-Ion and NiMH cells, while being about as cheap to produce as any garden-variety car battery on the market. Disposal costs would be less than nickel- or lithium-based batteries, since the infrastructure is already in place to recycle old lead-acid batteries en masse. They're lighter, too.

Hopefully no-one pulls a Chevron on this one, seems like it could go a long way to making a practical electric car viable - not to mention the applications for existing products.

J Tiers
06-17-2009, 11:40 PM
He's a bit late to the party, but a nice effective job.

I was told many years ago that many of the engineers at Motorola (now On Semi), who naturally had access to large MosFets and IGBTs etc cheaply, had converted S-10 pickups to electric. That was almost 20 years ago now.

I think some had done the 3phase, others were doing PWM DC.

As for the patent, using a battery of any sort in an electric vehicle is, or should be, non-patentable..... They existed 100 years ago.

And an NimH battery powered vehicle is quite "obvious to one skilled in the art"...... it is, or should be, no more patentable than a "pink wheelbarrow".

Alistair Hosie
06-18-2009, 04:41 AM
No matter what we have to take our hats off to this young man he's a genius in my eyes he's done alot of things most don't have the energy or will power to even try why not just encourage him a few more people like this lad are needed in this world,ten out of ten say I well done young sir.That's alot of impressive work you've done there .Alistair

Evan
06-18-2009, 08:18 AM
I always wonder how these things work in - 30 degree weather, when the batteries are cold, they loose capacity. Then you also need heat for the inside of the vehicle.

That isn't as big a problem as it may seem at first. The batteries will warm up quickly as they do work just like an IC engine and full capacity will be available. Cabin heat is available from the waste heat of the motor and the batteries, note that the motor is liquid cooled. It will be necessary to be sure to plug in the vehicle to prevent the batteries from freezing in the discharged state but then we have to plug in an IC engine heater too. It is also possible to store some of the waste heat in a sodium acetate salt phase change solution in a small tank. That heat can be used to warm the cabin and batteries before start up.

Add a few fuel cells that burn ethanol and you have a true hybrid that uses only ultra clean renewable energy and would have much better range than a pure battery only EV.

I have already saved enough electrical energy here with my recent power saving project to fully pay for the operation of an EV. That includes the actual electricity cost and the amortized cost of battery replacement. Switching to an EV is what I am working toward for much of my personal travel locally and the fuel cell option will be available at reasonable cost in the near future.

MickeyD
06-18-2009, 09:25 AM
Motorola converted a little Dodge Dakota and it was horribly underpowered. I looked at buying it a couple of years ago from the/then current owner and it was really a kludge. This guy has done a much cleaner build than Motorola.

J Tiers
06-18-2009, 09:53 AM
A number of years ago, kits and parts were widely available (if you knew where to look) for conversions.

The VW rabbit was a favorite, as was the S10 or other small pickup.

I don't know about the "official Motorola" vehicle, but the ones the engineers did for themselves were often rather snappy in performance.

The performance is ultimately dependent on the motor used, in any case. The one this guy used is actually a motor for a larger vehicle, a Ranger pickup. Small wonder that it is better performance.

As of 20 years ago, the available motors were relatively limited, with no noticeable EV market. The only EV sold in that time period was that really silly wedge-shaped thing (i've forgotten the name). The one that was indeed underpowered, lacking in any form of heating, and which had, IIRC, brakes that would fall off the axles if you tried to stop fast.

Not what you'd call a viable product, except in a 3rd world location (but there, you couldn't recharge it)

Spin Doctor
06-18-2009, 10:17 AM
I believe in the viable electric car for all climates when the sell them in Fargo, Eagle River, International Falls and Points North

Evan
06-18-2009, 12:01 PM
Electric has a much better future than any other option, especially hydrogen. The basic problem with hydrogen is power density and that is unsolvable since it is a characteristic of matter. Electric is already fully usable for short range and there is no absolute limit on the energy density achievable with batteries that matters except one.

The more energy you stuff into a container the more it begins to resemble a bomb. This has already been a major factor in the advancement of battery capacity. Lithium batteries were introduced in the late 60s and were mandated for use in Emergency Locater Transmitters in the 70s. That turned out to be a bad idea since they infrequently would blow up, usually just behind the pilot's left ear on a light plane.

The power density of batteries is approaching the point where they will be regulated by federal agencies in some way. It's already easy to make a simple incendiary device with nothing more than a few nicads and some wire. Back in the early 80s one of the battery manufacturers came out with some really high capacity lithium 9v form factor batteries. I still have one in my wireless doorbell and it still works 20 years later. They were pulled from the market after a few unpublicized events where they shorted in peoples pockets and exploded.

More recently we have the problems with exploding cell phone and laptop batteries. This will continue to be a serious drawback especially since in high power applications such as electric vehicles it isn't possible to predict and then modulate current draws to "safe" levels. Just on my simple electric bike it will draw up to 50 amps at 24 volts when accelerating from a stop. The batteries I use are capable of producing 250 amps at 12 volts each.

If we see a tenfold increase in power density which is needed to make batteries truly competitive with petroleum fuels then we have a situation where a battery is even more dangerous than a tank of gasoline. It's easy to make gasoline burn but it isn't easy to make it explode. Batteries however are generally sealed units that must withstand considerable internal pressure in operation. The design constraints mandate that the battery withstand as much pressure as possible to enable recombination of gases into the electrolytes but the safety constraints mandate that the battery vent easily which greatly reduces lifetime.

lane
06-18-2009, 08:05 PM
I have been doing the machine work for an old man doing that . He built a electric Chevrolet Suburban That thing is something else.10,000 miles on a charge is what he thinks . Me I don`t know .That would be something .

Spin Doctor
06-18-2009, 09:42 PM
Just what is the current status of mechanical battery systems? IMO they would be ideal in that they should be able to be charged up at a rate much faster than any electro-chemical battery. But there some nagging problems IIRC

Evan
06-18-2009, 10:30 PM
If you mean flywheels then the problem is similar. What happens when you try to flip over a 100,000 rpm gyroscope that contains perhaps a 1/4 megawatt hour of energy? You have surely seen occasional articles about how they developed this or that flywheel that turns to hot fluff if it explodes, safely shredding intead of turning into a projectile. What they never mention is the peak torque value that it transmits to the housing and how you prevent the sudden application of several thousand foot pounds of torque from first turning the vehicle into a giant toy top and then ripping it all apart like a helicopter crash.

J Tiers
06-18-2009, 10:59 PM
The only obvious answer is not to flip it over..... In any case, flipping it might rip it out of its mountings, un;less it is mounted 'free".

You would have to mount it without restraining it at all, in gimbals or the like. Some designs have no shaft or shaft bearings.

The energy will have to be input and extracted by electric means, no mechanical means can do the job with reasonable designs. That being a given, the restraints on free mounting are much less.

As for electric cars, right now they are still at the "cute idea" stage to a great extent...... and this IS due to batteries.

The range on most electrics so far is short, and that is made even more punishing by the fact that once out of power, it is many hours before you can go anywhere again. In a power failure, you are dead in the water, you are going NOWHERE.

The power density for hydrogen may still be low, I don't know what the one-tank range is at the moment. But there is one immense advantage that so far the electric has not had, and that is that you can fill up in a reasonable time, and be on your way again.

There was a proposal to fix this for electric cars by having exchangeable battery packs. You'd pull up, and in a few minutes the old pack would be slid out, and a fresh charged pack slid in.

There are a huge number of issues with that, even though it is a very sensible idea on the face of it.

First, it calls for a standardization that probably would never exist.... Even if it did, there would soon be a 'super platinum class" pack which could be slid into the BMWs and so forth by certain exclusive dealers, (but would not fit other vehicles) , just so those snooty Daimler and BMW drivers wouldn't have to deal with the rest of us quite as often....... And that would rapidly extend to the peasants (us) as the "exclusivity factor" was marketed.... before long it would be hard to find a regular one to fit your vehicle.

Second, one size would not fit all to begin with, there would be "size A", Size B", etc. And so there would almost certainly be issues with supply of certain sizes in certain areas, or planned obsolescence when a certain type of pack would "no longer be supported" in your area, or at all....

Third, the pack you get might have been just nearly destroyed by some teenage driver, or be overdue for replacement so that it is at the end of its capacity...... you'd be back before long, or left stranded..... victim of the "U-Haul battery" syndrome... "it ain't mine, so I just charge it and slam it in another car, I ain't paid to think".

Flywheels that are "safe" are a not-so-funny joke........ Anything that stores enough energy to move a lot of mass a hundred miles is a bomb of some sort. A flywheel that got loose could roar away through houses and walls, crowds of people, etc. If it "turned into fluff", then where does the energy go? That has to be considered.

As dangerous as gasoline is, it is reasonably difficult to make it do anything but burn. A battery pack has a number of hazards, electrocution, arc flash burns, possible explosion, a sort of 'china syndrome" meltdown, etc. Batteries are hard to "safe" when you need to work on the vehicle.

I really do NOT like seeing things like that battery "basket" that apparently went, unprotected, under the car in back where teh fuel tank was. Seems very exposed to a lot of hazards. A piece of metal bouncing up from the road, flipped up by a tire, could really do some damage, unless there are things I didn't see in the pictures.

Liquid fuel packs more energy in less space and weight than nearly anything else that you can imagine which can be practically put in a small vehicle. It is awfully hard to beat. Anyone waiting for the electric airplane?........................

My boss's comment, after seeing the website, was that the guy had a LOT of money........ Whole lot of Optima batteries, etc.......

fasto
06-19-2009, 12:02 AM
There was a proposal to fix this for electric cars by having exchangeable battery packs. You'd pull up, and in a few minutes the old pack would be slid out, and a fresh charged pack slid in.

I designed a battery controller for a German or Austrian company that had invented a pumped-electrolyte battery where to do a flash recharge you just pumped out the "discharged" electrolyte and pumped in "charged" electrolyte.
The battery controller operated pumps, diverter valves, etc. based on various inputs.
The battery technology apparently did work, as I drove around for a short time in a Mitsubishsi sedan converted to electric power, using this battery.
I believe the electrolyte was an extremely hazardous material, which put paid to the project.

Evan
06-19-2009, 12:51 AM
Anyone waiting for the electric airplane?........................


Not any more.

http://ixian.ca/pics6/eplane.jpg

Technical Details
Motor: 18HP/13.5KW Direct-Drive
Cruise Speed: 70MPH
Max Speed: 90MPH
Flight Duration: Max 1.5 Hours - 1 to 1.5 Hour Flights Most Common
Controller: Pulse Width Modulation electronic speed control for highest efficiency.
Battery Packs: Custom built 5.6kwh lithium-ion polymer for highest capacity per weight (specific energy density) High discharge rate capable of full power takeoff and climb.
Weight: Empty weight w/battery packs
Maximum Take-off Weight (MTOW)
380 lbs (172 kg)
625 lbs (283 kg)


http://www.electraflyer.com/electraflyerc.php

J Tiers
06-19-2009, 09:56 AM
Not any more.


Technical Details
Motor: 18HP/13.5KW Direct-Drive
Cruise Speed: 70MPH
Max Speed: 90MPH
Flight Duration: Max 1.5 Hours - 1 to 1.5 Hour Flights Most Common
Controller: Pulse Width Modulation electronic speed control for highest efficiency.
Battery Packs: Custom built 5.6kwh lithium-ion polymer for highest capacity per weight (specific energy density) High discharge rate capable of full power takeoff and climb.
Weight: Empty weight w/battery packs
Maximum Take-off Weight (MTOW)
380 lbs (172 kg)
625 lbs (283 kg)




So that performs the same task as a small Cessna?

I do not think so.

Doing some simple arithmetic shows that while the device is in fact technically an airplane, it suffers from the same issues as the bulk of other electric vehicles...... lack of capacity, lack of range, and extreme sacrifices in other characteristics to get to that point..

Your range will be about 100 miles, possibly stretched to a maximum of 130 miles, according to their own specs.

naturally that will be reduced by the required mandatory reserve range, although as a modified sailplane, perhaps that could be relaxed.

There are many people who, even if they were pilots, could NOT fly that aircraft, because their weight would exceed the permissible payload, even if they emptied their pockets of loose change. As for them taking a change of clothing, no dice.... Passengers? Don't even think about it.

Two very small women might be possible, if they carried hardly any luggage.

MTOW 625, empty weight (not including electricity :D ) 380 lb. Difference = 245 lb, representing the entire payload.

Now, it is certainly an interesting creation. of that there is no doubt. Slightly less practical than a Honda Insight, or a "smart car", however. I suspect it is more "useful" as a rich person's toy than as a "real" aircraft.

But it is also an object lesson in the difficulties of electric vehicles in general.

The ONLY way to get over the difficulties is to build a better bomb.... er.... battery.

It may be "better" in that it is lighter per kWh, or it may be "better" in that it is integrated into the structure of the vehicle in such a way as to do "double duty", and justify part of its weight that way.

It is really hard to compete with a battery which weighs only about 0.3 lb per mile of range. And that is what we have now.

Evan
06-19-2009, 10:20 AM
It is an electric plane Jerry. You didn't mention any qualifiers. In fact, it does better than most electric vehicles.

BTW, it is an ideal application for electric power. Recreation gliders often need to carry ballast to get enough "penetration" in turbulent conditions. Motor gliders are much more usable because of the ability to extend a glide to really useful distances. The range on that isn't 100 miles, it is essentially indefinite. With 100 miles of assist and no worry about the engine starting for even a short assist a good pilot could fly that glider across the continent.

J Tiers
06-19-2009, 10:33 PM
That DID occur to me, but I then realized that they almost certainly increased the wing loading quite a bit to get it to do as well as it does.

And, the prop is a lot of drag, so I then decided that the most likely situation is that it isn't really a sailplane, and isn't quite a powered craft......

The range is assisted by the fact that while an airplane must go uphill all the time, it is a shallow slope, and otherwise all air friction.

A ground vehicle has a lot of sources of friction, and probably don't get much help from regeneration... Regeneration sounds better than it ever does, and IIRC, most electric railways that tried to use it dumped it in favor of resistor braking.

I admit to being surprised they do that well

Spin Doctor
06-20-2009, 01:07 PM
There is another way to make long distance electric cars practical. If you have an electrical pickup of some sort on the vehicle and the power supply embedded in the roadway long distance travel on the interstate should be possible. With a device similiar to an I-Pass http://www.illinoistollway.com/portal/page?_pageid=133,1392734&_dad=portal&_schema=PORTAL that records how much juice you use and readers at the exits once a month you get a bill in the mail for power used. Now as to cost and just how you generate the power to start with, well that is another issue. but if the cost of power is say 25 to 50% the price of gas could the system be made to pay for itself over time?

aboard_epsilon
06-20-2009, 01:47 PM
There is another way to make long distance electric cars practical. If you have an electrical pickup of some sort on the vehicle and the power supply embedded in the roadway long distance travel on the interstate should be possible. With a device similiar to an I-Pass http://www.illinoistollway.com/portal/page?_pageid=133,1392734&_dad=portal&_schema=PORTAL that records how much juice you use and readers at the exits once a month you get a bill in the mail for power used. Now as to cost and just how you generate the power to start with, well that is another issue. but if the cost of power is say 25 to 50% the price of gas could the system be made to pay for itself over time?

everything looks great at first ..

you will be able tp save money ..
that's up uintill they get greedy and start charging more for it ..

same with everything..they done it with diesel and lpg in this country .

we know petrol can be sold cheaper ..do they ..no ..

find some sort of free energy ..AKA veg oil..and they will even tax you on that in the uk ...........

all the best.markj

Evan
06-20-2009, 01:53 PM
And, the prop is a lot of drag, so I then decided that the most likely situation is that it isn't really a sailplane, and isn't quite a powered craft......
Most motor gliders use a fold up prop. It's lightly spring loaded so that when it stops and is moving forward the blades fold back, practically no drag. This really does qualify as a powered aircraft since it can take off from ground under it's own power. A lot of motor gliders can't.

Jim Shaper
06-20-2009, 03:00 PM
It is an electric plane Jerry. You didn't mention any qualifiers. In fact, it does better than most electric vehicles.

BTW, it is an ideal application for electric power. Recreation gliders often need to carry ballast to get enough "penetration" in turbulent conditions. Motor gliders are much more usable because of the ability to extend a glide to really useful distances. The range on that isn't 100 miles, it is essentially indefinite. With 100 miles of assist and no worry about the engine starting for even a short assist a good pilot could fly that glider across the continent.

As long as they didn't bring anything with them... :rolleyes:

kendall
06-20-2009, 03:06 PM
Stupid ideas

Why not pick up coils on the underbody, and embedded magnets in decelleration lanes and downhill runs? Dual benefits, slows you down, and charges the batteries would also work when the roads are slick.
More applicable in certain areas, and expensive for construction, but 'free' afterwards, though I think commercial interests would reverse it so they get to resell the electricity you produce.

I've always been interested in electric vehicles, but for most use they simply don't have the range. Electric boats are good for in harbor use, but for long distance you NEED a charging system. Generally it's an IC engine running a generator. For some boats the generator takes as much horsepower as driving the boat, so it's more efficient to run the prop directly. I figure a generator/motor between prop and IC with a clutch on both ends of the motor/generator, would give the best overall results. For basic maneuvers use the electric motor alone disconnected from the IC, for longer runs drive the prop through the motor/generator, and disconnect prop to run as a simple generator. would provide the best of both worlds, and consolodate everything into a neat little package. With the motor/gen used as alternator, starter, and generator, would reduce duplication, would not require a huge battery stack, and give the instant (quiet) power of electric drive with the range of an IC.

Ken.

J Tiers
06-20-2009, 05:50 PM
Most motor gliders use a fold up prop. It's lightly spring loaded so that when it stops and is moving forward the blades fold back, practically no drag. This really does qualify as a powered aircraft since it can take off from ground under it's own power. A lot of motor gliders can't.

Right, and the prop does not seem to fold on this one, or they would proably have made a point of that. If they did, I missed it.

I imagine they went for max payload, since they START with the batteries and motor, and go from there. It would have to be credible....... 245lb total p/l is minimal, much less and it is just a fancy brick.

I expect it's going to do significantly better gliding than an F4 Phantom...... or even most Cessnas etc. But probably not nearly as well as it would have as a straight glider.

Evan
06-20-2009, 06:52 PM
Glide ratio has very little to do with weight. It's controlled by the lift to drag ratio. All weight does is to change the speed at which the maximum lift to drag occurs and not by very much. You can't tell a folding prop from any distance. If it's stopped the drag penalty isn't much even if it doesn't fold.

My instructor showed me that by turning off the engine on the Fleet Canuk I was learning in. He set up a stable glide angle with the engine windmilling and noted the rate of decent. Then he pulled up until the engine stopped and allowed the aircraft to resume decending. The rate of decent was much less with the propellor stopped. Once it stops it tends to stay stopped because of piston compression.

J Tiers
06-20-2009, 11:16 PM
Glide ratio has very little to do with weight. It's controlled by the lift to drag ratio. All weight does is to change the speed at which the maximum lift to drag occurs and not by very much. You can't tell a folding prop from any distance. If it's stopped the drag penalty isn't much even if it doesn't fold.

My instructor showed me that by turning off the engine on the Fleet Canuk I was learning in. He set up a stable glide angle with the engine windmilling and noted the rate of decent. Then he pulled up until the engine stopped and allowed the aircraft to resume decending. The rate of decent was much less with the propellor stopped. Once it stops it tends to stay stopped because of piston compression.

yes, and yes.

OTOH, if you increase the wing loading, you will increase the drag somewhat, as you probably must go faster (rapid increase of losses with speed) or increase the angle of attack.

I would certainly expect the prop drag to be much less stopped. At least if it were a decent prop and actually worked.......

A folding prop obviously is better. On a craft with the low drag that undoubtedly has, I would expect the prop drag even stopped to be much larger as a proportion of the total than for a dirtier aircraft.

I understand that most aircraft will glide farther than you would expect if properly handled.

In any case, it is an interesting aircraft. It is somewhere between an electric bicycle , a golf cart, and an Insight hybrid (or "smart car") as far as practicality, but it is certainly a feat to do as well as they did.

Starting with a sailplane was obviously a good move.

danlb
06-21-2009, 01:51 AM
I keep hearing about chevron keeping NiMH batteries out of cars, I have to wonder... is there only one formula for NiMH batteries? Is there really a patent from 1990 that is still in effect refarding NiMH batteries? Can a company really restrict the use of their products by competitors without running afoul of 'restraint of trade' laws?

I searched for the patent that supposedly keeps NiMH out of EVs, and I did not find it. I suspect that the specific battery used by Toyota (the EV-95) violated a specific patent and not a general one. I suspect that the dispute was over the patent for a 'prismatic' packaging, which allows more tightly packed cells.

I've known a few poeple using EVs. All were quite happy with their cars. If the car matches the way you use them, they are great. My wife sedom drives more than 30 miles a day, so she would do fine with a nice electric compact or mid-sized car.


Dan

Evan
06-21-2009, 02:03 AM
Most gliders are too light to extract maximum lift to drag from the design. That is why they have provision for ballast tanks. By increasing the wing loading the speed of maximum L-D increases and the angle of attack is actually reduced since the lift goes up as the square of velocity. Induced drag, which is independent of parasitic drag, goes down faster with lowered angle of attack than profile drag goes up with speed until a certain point is reached. Glider designs aim to be below the critical weight since it is easy to add weight if below the best weight but impossible to remove it if you start above the critical point. The main reason for wanting to be below the best LD weight is to decrease turning radius so that the glider can turn sharper to stay in tight thermals.

I wish I had found this explanation during the "how is lift produced" debate.

http://selair.selkirk.bc.ca/Training/Aerodynamics/induced.htm

It rather conclusively disposes of the pressure argument.

J Tiers
06-21-2009, 10:30 AM
That's a good explanation.

I was puzzled by your statement, however......... you said



It rather conclusively disposes of the pressure argument.

However, the "pressure argument" that I think of concerning lift is not at all affected. In fact, in your linked explanation, they discuss that, they endorse the idea of a higher pressure beneath the wing, and they use the exact same illustration that I did in that discussion.... the tip vortex . I would have to say that they and I have a 100% agreement about lift.


As we learned earlier when we studied lift, a pressure difference forms between the top and bottom of the wing. ...................The picture to the left shows that the wingtip vortex is caused by the air flowing around the wingtip from the high pressure area below the wing to the low pressure area above the wing. A clockwise (as viewed from the rear) vortex forms at the left wingtip and a counter-clockwise vortex forms at the right wingtip. You can see this quite clearly in the clouds of the photograph above.

Evan
06-21-2009, 10:51 AM
The interesting thing that I forgot is that the pressure difference actually causes a forward circulation from the bottom of the wing to the top around the front of the wing and that this is responsible for the downward deflection of the air from the top of the wing.

Note also that this is being taught at Selkirk College which is one of the foremost Aeronautical Engineering schools in North America. They have credit transfer agreements with Embry-Riddle Aeronautical University in Arizona and Florida.

J Tiers
06-21-2009, 11:30 AM
The interesting thing that I forgot is that the pressure difference actually causes a forward circulation from the bottom of the wing to the top around the front of the wing and that this is responsible for the downward deflection of the air from the top of the wing.


I'm not *100% sure that the net flow is forward under the wing*...;)

There is a theoretical way in which you could describe positive and negative flows around the wing, however......

They describe that "upwash" as slightly deflecting the lift vector from entirely vertical to slightly raked aft.

The wing is "intercepting" a volume of air as it moves, and some of that air effectively circulates up and around the front. You would expect that.

And the "influenced volume" of air extends forward of the wing (at least at subsonic speeds). That will mean a pressure zone ahead of the wing, which they in fact describe.

Note that the upwash effect will be dependent on the angle of attack. If the wing AOA was 90 degrees, the air would split more-or-less evenly, some going around the "leading edge", some around the "trailing edge".

As the AOA varies to a lower angle (from horizontal), the split also decreases, until at an exact zero AOA there would be an even split above and below, with NO upwash.... and naturally no lift either, since the lift is dependent on the AOA.

Carld
06-21-2009, 12:47 PM
:eek: WOW this guy is no back yard bozo. He did a nice job and whether it's cost effective or not he sure seems to have enjoyed his project. It may be over kill in some ways but what the heck, it's his creation so it's his way or the highway.

I really like it and it says a lot about his abilities.

As for the lead batteries they can be built to be easily rebuildable. Ma Bell used glass jars on long racks for years to supply their needs and they could be rebuilt easily. I did work for Ma Bell in Charleston Mo and got to see the racks of batteries a lot. I used to have one of the glass jars but it went somewhere in one of my moves.

Peter S
06-21-2009, 09:03 PM
There was a proposal to fix this for electric cars by having exchangeable battery packs. You'd pull up, and in a few minutes the old pack would be slid out, and a fresh charged pack slid in.

A couple of months back I caught just a brief part of a BBC science news programme on the radio. Some university? had suceeded in charging Lithium batteries in a very quick time, i.e. greatly reduced charge times.

Forget changing battery packs, how about a quick recharge? I haven't heard anymore about this, but they had it working on some small scale anyway.

This sounded to me like a possible answer to those ridiculously long charge times being quoted for the Tesla etc. (A car which you can't use for very long periods while it is recharging).

lazlo
06-21-2009, 09:17 PM
Can a company really restrict the use of their products by competitors without running afoul of 'restraint of trade' laws?

Absolutely. Intel doesn't have a patent on the x86 instruction set, but they have a huge patent portfolio and an army of lawyers who will sue you into the Stone Age. So unless you're a huge company with a blanket cross-licensing agreement, like IBM and AMD, you can't make an x86 microprocessor. That's the reason for Transmeta's existence.


I keep hearing about chevron keeping NiMH batteries out of cars, I have to wonder... is there only one formula for NiMH batteries? Is there really a patent from 1990 that is still in effect refarding NiMH batteries?

I searched for the patent that supposedly keeps NiMH out of EVs, and I did not find it.

It's a set of patents starting in 1998, and continuing to 2005: patent number 6,255,015 (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6,255,015.PN.&OS=PN/6,255,015&RS=PN/6,255,015), 6,969,567 (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6969567.PN.&OS=PN/6969567&RS=PN/6969567), et al:

This is the original Stan Ovshinsky patent:

6,255,015 (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6,255,015.PN.&OS=PN/6,255,015&RS=PN/6,255,015)
We claim:

1. A multi-cell, plastic, nickel-metal hydride monoblock battery, comprising:

a battery case including one or more partitions dividing the interior of said case into a plurality of cell compartments;

a plurality of nickel-metal hydride batteries disposed within said case; and

one or more coolant channels integrally formed with at least one of said partitions, said channels disposed between at least two of said electrochemical cells.

6,969,567 (http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6969567.PN.&OS=PN/6969567&RS=PN/6969567)
We claim:

1. A multi-cell battery, comprising: a battery case; and a plurality of electrochemical cells housed in said battery case, each of said cells including: at least one positive electrode, at least one negative electrode and an electrolyte; and an enclosure housing said at least one positive electrode, said at least on one negative electrode and said electrolyte, said enclosure including a gas permeable membrane allowing passage of cell gases into and out of said cell but preventing passage of said electrolyte out of said cell, said membrane comprising at least one corrugated layer of a membrane material.

Evan
06-21-2009, 10:20 PM
I would guess that the enforcable parts of those patents are the integral cooling channels and the semipermeable membrane. The rest is prior art. The two items I mention probably are as well but all it takes is some small differences to keep it in court. For example, they mention corrugations. That's enough difference to claim a patent.

J Tiers
06-21-2009, 11:57 PM
Better even than that, you have to read claims carefully......

Wherever they say comprising "A" AND "B" AND "C", you are as safe as houses if you do not have ALL of the features.

In other words, for instance in the first quoted claim, the connective 'and" means that if you do not have "integral" cooling channels, you can thumb your nose at them, at least in theory.

Of course there are probably 15 or more claims, and another may not include that. But in general, claim 1 will be the most general, with all others becoming more and more specific.

Reality is that they will sue you anyway, and quibble their butts off about every detail, asserting that you DO indeed have all the bits and pieces claimed, and therefore you are a dirty little infringer who must be made to pay and pay.

This will cost so much money to defend against that most businesses will knuckle under. They will, often purely because the possible profits are dwarfed by the several million dollars the patent holders will attempt to make it cost you to get what you are fully and totally legally entitled to have.

This is the strategy that (probably) Intel and certainly others will pursue, if you get too close. They have to. They have a lot riding on keeping exclusivity, and they depend on you not being motivated enough to challenge that if you DO have the money, or simply that you won't have the money to mount any challenge in teh first place.

My former employer paid to license a patent which was totally and completely anticipated by a different US patent. The advice we got was to expect defense to cost $2 million, and to also expect that the particular court would NOT uphold us and overturn the patent, because they basically never do.

Yes, it is indeed justice bought (and sold) to the order of the rich.

Once in a while the little guy wins, but never against a large corp......

lazlo
06-22-2009, 12:39 AM
Reality is that they will sue you anyway, and quibble their butts off about every detail, asserting that you DO indeed have all the bits and pieces claimed, and therefore you are a dirty little infringer who must be made to pay and pay.

Once in a while the little guy wins, but never against a large corp......

Exactly -- the claims (those were the first of many that I quoted) are vaguely written, probably intentionally. So unless you want a long and drawn-out court battle with Chevron, you'd better find a different battery technology...

They can repeat this again with Lithium Ion, or LiPo batteries if they want: find a small startup company with a Lithium Ion patent, preferably related to electric or hybrid vehicles, buy the patent portfolio, and then tie-up all related patents in court for the next twenty years.

Ain't patents great? :mad:

Evan
06-22-2009, 12:52 AM
I wonder why China is winning the economic war?

danlb
06-22-2009, 02:18 AM
I was not questioning the ability of a company to enforce a patent.

I was wondering if Chevron could legally choose not to license their technology to a company simply because the battery would be used in a car.

Resraint of trade defined:
Contracts or combinations that tend, or are designed, to eliminate or stifle competition, create a Monopoly, artificially maintain prices, or otherwise hamper or obstruct the course of trade as it would be carried on if it were left to the control of natural economic forces.


I think that the real reason that NiMH are seldom used for EVs is that they are not best suited to the task. They do not accept rapid charging, they do create lots of heat, they are damaged when over discharged. Their normal life under heavy use is 3 years or 500 cycles, whichever comes first, and they self discharge something fierce.

Recent developments have brought us some better batteries in all chemistry. Maybe with some luck they will find their way into cars before we run out of fossil fuels.


Dan

Evan
06-22-2009, 04:30 AM
Better batteries are akready here. Coming sood to an electric vehicle near you with a 90 percent recharge time of FIVE minutes.

From Toshiba:


SCiBTM is a new type of rechargeable battery with superb safety.
By using newly developed oxide materials, SCiBTM holds high resistance toward thermal runaway resulting from short circuiting caused by physical stress. SCiBTM also have excellent characteristics such as, long life with minimal capacity loss even after 6,000 charge-discharge cycles, rapid charging capability with ability to charge 90% of the capacity in as fast as 5 minutes. High power output with performance equivalent to that of an EDLC (Electric Double-Layer Capacitors), and good cryogenic performance with ability to function even at -30℃.

http://www.scib.jp/en/

These are not a laboratory curiosity, they are in full commercial production and are building a second factory as we "speak".




Toshiba to Boost EV Battery Production by 2010

Written by Josie Garthwaite5
Posted December 24th, 2008

The global market for electric vehicle batteries could grow to $19 billion by 2010, and Japan’s Toshiba Corp. wants an ample piece of it. The electronics giant stepped up the race to supply rechargeable batteries to automakers with news that it plans to build a second factory for its rapid-charge lithium-ion battery. Toshiba designed the so-called SCiB (Super Charge ion Battery) for cars and industrial equipment. It expects construction of the plant to begin next fall, with batteries coming off the assembly line in 2010.

Today’s announcement comes just a week after more than a dozen U.S. tech companies formed a coalition in an effort to compete with dominant Asian battery makers. With Panasonic and Sanyo joining forces last week, and Toshiba staying on track with its production schedule, Japan’s powerhouses, at least, are ready for the American group.

Toshiba’s latest move confirms the game plan it laid out for the SCiB battery just over a year ago: “Application in hybrid cars is also planned,” the company said last December, “with the intent of extending application to electric cars in the future, after advancing development of a high-performance SCiB cell.” This fall, Toshiba snagged its first supply agreement for the battery in a deal with Schwinn for electric bicycles.
A city in northwest Japan, Kashiwazaki, ranks as Toshiba’s “primary candidate” for the new factory, according to today’s release. Kashiwazaki offers subsidies for green car technology, and has applied for recognition under Japan’s “PHEV town” program, which would qualify it for incentives to build out hybrid and electric vehicle infrastructure.
http://earth2tech.com/2008/12/24/toshiba-to-boost-ev-battery-production-by-2010/

J Tiers
06-22-2009, 09:51 AM
I was not questioning the ability of a company to enforce a patent.

I was wondering if Chevron could legally choose not to license their technology to a company simply because the battery would be used in a car.

Resraint of trade defined:
Contracts or combinations that tend, or are designed, to eliminate or stifle competition, create a Monopoly, artificially maintain prices, or otherwise hamper or obstruct the course of trade as it would be carried on if it were left to the control of natural economic forces.

Dan

You own a car (probably).

Can you legally prevent anyone else from using your car?

Or are you forced to lend it to anyone who asks?

The answer is the same, and for much the same reasons, with regard to a patent.

Evan
06-22-2009, 09:59 AM
Not a very good analogy Jerry. You had to pay a significant part of your income for that single car and you don't have the right to prevent anybody else from driving a car that looks like yours.

TGTool
06-22-2009, 07:08 PM
Dunno whether this is more on or more off topic.

A couple days ago there was a short piece on the radio about someones's proposal for a car that used compressed air instead of electricity for the stored energy. The basic idea was the same, that a smaller engine would serve, augmented by the compressed air for startup AND using some compressed air for supercharging on acceleration. Regen braking would again recover energy by compressing air. They figured this would cost considerably less than the electric option. This also seems much more up the alley of HSM efforts. I haven't tried to track it down in print, but the idea sounded like it had merit.

aboard_epsilon
06-22-2009, 07:27 PM
air.... cant see that being efficient ..my 5hp comp just about powers a die grinder ..that is probably less than 1/10th of a hp.

all the best.markj

Evan
06-22-2009, 08:21 PM
There is no possible power system that is less efficient than compressed air. You would do better running a car on coal. A compressed air engine that runs on stored compressed air loses the heat of compression of the air before it can be used to expand the air. It's a type of heat engine where most of the heat has already been lost from the energy source before the residual can be used. The efficiency level of a compressed air engine is probably no better than 5 percent and I think that is probably generous. The air is no more than a wind up spring when the heat is gone.

J Tiers
06-22-2009, 08:40 PM
Not a very good analogy Jerry. You had to pay a significant part of your income for that single car and you don't have the right to prevent anybody else from driving a car that looks like yours.

But the REASON is that I OWN that one..... and I can prevent others from using it, along with whatever improvements and accessories are encompassed within it positively distinguishing it from all other cars of superficially similar appearance. I do not have to have ANY reason, and I need not disclose my reasons.

the patent papers "look alike" also, but I OWN mine. I spent a significant portion of my corporate (or personal) income in the R&D to develop the idea and secure the patent. I can prevent YOU from using MY patent, along with whatever improvements etc are encompassed within it positively distinguishing it from other superficially similar patents, devices, etc. I do not have to have ANY reason, and I need not disclose my reasons.

Your likes and dislikes don't form an absolute area-wide adjudication of acceptable analogies ...........:D

Evan
06-22-2009, 08:57 PM
It's called intellectual property as opposed to real property. The two are not equivalent. If you steal somebody's car they don't need to prove it was stolen, only that you did it. If you infringe somebody's patent they have to prove you really did it and that you actually cost them money in some way or there isn't a chance they will collect damages. If the best they can prove is that it may cost them money the best they are likely to get an injunction telling you to cease and desist.

Taking a car is a criminal offence. Infringing a patent is a tort offence. A tort offence is a civil offence and the only remedies are injunctive and monetary. The fact that the legal process can be very expensive isn't a matter of law, it's a very unfortunate by product of how the system is structured.

J Tiers
06-22-2009, 09:59 PM
Whatever.

Either way I don't HAVE to let you use it.... which was the question

The remedies and "tortillas" don't change that ;)