Interesting topic brought up towards the end (page 3) on the are liberals stupid thread and I thought it needed it's own space to be bantered about since I am sure buy the topic title most did not bother with it.

One thing I have really enjoyed about being a member here is the contrasting opinions ( when people are not prickish) and the great links to interesting articles and technology amongst others that I probably would not be exposed to before I became an avid PFF reader. People here have a real knack for finding cool informative things to read and look at, so how about some electric car stuff?

The Tesla car is a good page. The only drawback is the price and range.

The DC motor in cars needs to be buried next to Edison's grave. In no way can they be viable as performance and economy engines.

Well, one thing I can say is that motors can't get much more efficient. The technology is all there except in batteries -- and the only problem we have with those are the properties of batteries.

Nickel batteries (Ni-Cd, Ni-MH) as well as Lithium-Ions found in most rechargable devices today have one major drawback: they can't supply as much power as is needed to drive a car. They are lightweight, and have "memory" effects in favor of driving patterns that stress them completely. But they are also pretty damn expensive. By "pretty damn expensive" think tens of thousands of dollars for a pack that could power an electric car. I guess that leaves those out, eh?

Lead-acid batteries - like those found in cars already - have made many improvements over the current technologies used in car batteries. The biggest markets for them seem to be in both cars and power backup devices, which have two very different needs. Backup devices generally stress the battery, by discharging it completely most of the time. Cars take a *massive* power draw for a very short time then slowly get recharged, rarely getting fully discharged. The downsides to these batteries are pretty massive: they're extremely heavy (being made mostly of lead) and have an "inverse" Ni-Cd memory effect. If you discharge them completely, you just cut their capacity in half. The upside is that they're cheap and readily available.

So, what do you get in current EV (electric vehicle) offerings? Lead batteries. But not of the backup or car variety - usually customized, deep cycle tolerant batteries. New technologies are being created to try to counteract the "memory" effect inside the batteries - to varying degrees of success. The added weight of these massive batteries, though, is a heavier vehicle. The weight you saved by removing the engine and lightening the frame is added back by the heavy batteries! What a pain!

Battery technology isn't far off. Lithium-Ion technology is under serious development to be used as a replacement for the lead-acid batteries of today. Their power output problem seems to have been fixed -- see Tesla Motors, who is building a sportscar to totally *smoke* all current gas powered cars -- but the cost is still pretty high to produce. Honestly, I believe the problem here is that there's no funding (via business) to help the development here, and while the cost is so high, there won't be any business to help develop cheaper batteries!

Someone's got to make the daring leap of faith to get this system started. It's so close, I can see electric cars all over the streets in just a few years. There's already an electric car dealer in town, but they're $13,000 and still built around lead batteries. Also can't take them on the freeway (due to range limitations they use a smaller motor that can't push its SIX aircraft-sized lead batteries around faster than 45). But the technology is definitely there.

------------------

'87 Fiero GT, Automatic, 153k miles, stock everything, just trying to make it all work again. :D

I think pure electric cars are a poor idea. They take to long to charge, the life of the batteries is to short, the power to charge them comes off the power grid, and they are hazardous and potentially deadly in accidents, fires, electrical shorts etc.. I had a friend that did a conversion for a company using lithium ion batteries and all the rest of the parts supplied by the contractor with specs. After building it and several test drives there was an electrical short that caused over 30 cells to blow up and the vehicle caught fire... burning interesting colors like green. The firemen hadn't ever seen anything quite like it, huge quantities of toxic smoke.

Hybrid I'm all for... plug in hybrids, gas or diesel/electrics, solar/electrics, fuel cell/solar, fuel cell/electric... lots of opportunities.

Hybrids are a win/win... increase power and economy while dropping emissions.

Too long to charge? What, at a gas station? One of the things people will have to adapt to with electric cars is the change of "fuel" points. If everyone had a gas pump in their garage, it would take too short a time. Here, with electric cars, the "gas station" is now the entire time your car is parked. You leave it at home, plugged in like your cell phone or laptop, then every time you leave you have a full "tank". There are no gas stations to stop at and get an inconveniently long "fill up" time. However I can forsee a problem with apartment renters who park in outdoor lots... yeah, that can become a problem. Guess that does need to be solved as well.

The life of the batteries is as long as you make them. If you abuse them, yes, they will die sooner. If you treat them properly they will last tens of thousands of miles. Personally, like I mentioned in my last post, I don't think lithium-ion batteries are ready for primetime, which is probably why your batteries had a problem. The short was probably caused by overloading the cells, causing a neat little chain reaction that blew the whole system. Some engineer was real bright putting that car together with lithium-ion batteries...

But you have a hard time going on a cross country cruise if you have to stop every hundred miles for 4 hours to recharge... But someone did show up at a shop I know with a EV1 in New York... not sure how they got it there from the south west.

As a short range commuter vehicle, neighborhood vehicle, or other short range applications with long enough down times, they can be viable. I'd like to see one with about a 300-400mile range.

[This message has been edited by Scott-Wa (edited 11-06-2006).]

I am going to be missing in action on this thread due to living on the Skykomish here in WA, the river is in the midst of possible major flooding event! river is already 3 feet over it's banks here,,,,,,,,,,,,,,,,,,, gotta go!

well, if batteries were stadardized to a single shape & capacity, the charge time could be iirrelevant. instead of plugging in and waiting - do a battery swap. and charge outside the vehichle. this also lets the charging system do a full charge cycle. makes the battries last much longer. but, batteries are HEAVY. maybe, if broken down to several 20-30 pound units.

quote Originally posted by AP2k: The Tesla car is a good page. The only drawback is the price and range. The DC motor in cars needs to be buried next to Edison's grave. In no way can they be viable as performance and economy engines.

I dont agree. Couple them to fuel cells, and you do have someting viable. ( yes, i know fuel cells are still in their infancy and are far to expensive, but costs will drop in time )

quote Originally posted by AP2k: The DC motor in cars needs to be buried next to Edison's grave. In no way can they be viable as performance and economy engines.

Why not have AC motors in cars? I don't think it is too unrealistic. Over the past five years or so battery good top of the line Material Handling Equipment (forklifts) have been chnaging from DC to AC motors. Granted most of the forklifts sold are still DC but AC is not a viable option as well.

Ultimately the challenge is to get the car to go as far on a battery full of electricity as it would if it was filled with gasoline and at a decent power and top speed level. I would be happy with a car that will do:

0-60 in 7-9 seconds
350 mile range
Top speed of 90MPH.
80% recharge in 2 hours.

For 95% of my driving, that would cover it. I do like the battery swap idea. There are a few gotchas (you can't easily opt for some expensive/higher range batteries if you have deep pockets), but for most driving it would certainly work.

But we are a far away from that. I am still guessing 20 years but I think it can be done.

[This message has been edited by TK (edited 11-06-2006).]

http://www.dynamotors.com/too_old.html


I think these guys will tell you motors can be more efficiant.

Batteries... Lith Ion , are xpencive , but with no memory, and their weight , they are the way to go... no doubt....

IMHO , electric cars are VERY viable at this point, I would do it, but it's cost is a bit much to swallow at once....

I would like to do this to the Fiero....

quote Why not have AC motors in cars?

For one thing because AC motors are just DC motors with tons of additional wiring and equipment to directly handle an untamed AC current without a bunch of converters.

Or maybe you're talking about stepping or servo motors - like the brilliant designers at Oxygen decided to use in my electric "Vespa". That thing uses a massive computer/controller on the side that takes the 48 volts of battery juice and slices/dices it up into phases of the motor. That, unfortunately, actually creates a much more complicated design (let me tell you that from experience here) and more power lost to heat on the controller *and* the motor. Talk about a step in the wrong direction.

AC motors, like those used in power tools and appliances, are actually less powerful and efficient than their DC counterparts. They're still used, however, because in order to convert from AC to DC with that much power would require a massive switching power supply, in the hundreds of dollars price range. So they just deal with what's there. Now, I've got a front loading washer, completely computer controlled, and it appears to use a type of DC motor, but I can't figure out for the life of me how the system can handle the 800-plus watts of power driving that motor... maybe they *did* finally start putting DC converters into the machines to make the motors simpler. I don't know. But one thing's for sure: they would never take DC and try to drive an AC motor.

edit:

quote ERROR !! - Browser Version - Sorry, you need a newer Browser to view our site. We have found that your browser is too old for our site to display correctly.

... You suck at posting links.

[This message has been edited by Falcon4 (edited 11-06-2006).]

The real issue with electric cars is conversion efficiency.

Any time you change power from one type to another, it's expensive and lossy. For example, the best internal combustion engines only put about 40% of the chemical energy of their fuel out through the driveshaft; the rest comes out as waste heat, either through the exhaust pipe or the radiator.

When you charge a battery, the amount of electricity you actually store in the battery ends up being less than 15% of the energy consumed--and 15% is a best-case scenario; if you use a "rapid charge" the efficiency goes down.

In monetary terms, if you pay $0.10 per kilowatt-hour of electricity, you are storing not more than $0.015 worth of electricity for each kilowatt-hour you try to cram into your batteries.

My Ford Escort's 1.9 liter engine generates around 65 kilowatts of power at its maximum output (88 horsepower). It goes 0-60 in around 10 seconds.

It takes around 11 kilowatts to move a car at 55 miles per hour. Going 55 miles at that speed takes 11 kilowatt-hours of electricity. Storing that amount of electricity in any kind of battery requires you to expend a bit more than 73 kilowatt-hours of electicity; and that's $7.30 (at $0.10 per kilowatt-hour) to go 55 miles.

Ed

PS Hmm, put that way, $3 per gallon gasoline sounds like a bargain to me: at an average fuel economy of 36 MPG, my Escort will take me 72 miles on $3 per gallon gasoline.

Dude, your math is way, way off. Battery chargers do not have a 15% efficiency - not even close. I'd actually say my charger has about an 80% efficiency - I can calculate that nearly everything that went out on the last drive (60 amps acceleration / 30 amps cruising) came back into the batteries with the charge, with just slightly more going back in with the trickle charge to make up for the lost energy. It also doesn't take 11 kilowatts to move a car at 55 miles an hour. My charger puts out 11 amps at 48 volts DC, and that takes 900-1000 AC watts. Triple that for a cruising speed of 30 miles an hour - that's 3KW. Basically we could add 2.5KW more, plus some for additional drag, and that's 6KW -- charging -- at 55.

Apparently you never owned an electric vehicle. xD

(edit: and all these numbers were gathered not using label specs, but using a clamp meter for the amps and a wattmeter for the watts)

[This message has been edited by Falcon4 (edited 11-06-2006).]

quote Originally posted by edhering: PS Hmm, put that way, $3 per gallon gasoline sounds like a bargain to me: at an average fuel economy of 36 MPG, my Escort will take me 72 miles on $3 per gallon gasoline.

Hmm, put is THIS way - if you get 36 MPG, your car goes 36 miles for ever gallon of gas - regardless of how much the gas costs.

You suck at teh math.

Next you're going to try telling me there's something wrong with that? How would you suggest building a better meter?

quote Originally posted by Falcon4:

Tesla uses AC motors andgets %80-%90 efficiency at full RPM (read: 13.5kRPM). DC motors efficiency drops off inversely proportional to the RPM.

Its a major lapse of reason to state that AC motors are less efficient than DC motors when any electrical engineer will tell you otherwise. As for the driver circuit, its also quite efficient. We dont use vacuum tubes anymore, Falcon.

Lets also not forget about how you can step down current while maintaining speed with an AC motor for massive power savings. Try doing that with DC...

[This message has been edited by AP2k (edited 11-06-2006).]

quote Originally posted by Falcon4: Next you're going to try telling me there's something wrong with that? How would you suggest building a better meter?

I've just never seen a clamp on meter for DC before. I was under the impression that they only worked on AC circuits because they measure the induction from the magnetic field around the conductor, and since the field is static on a DC circuit, there's no induction to measure.

I've always used serial ammeters for DC, and used my Amprobe clamp meter for AC. Clamp on makes life much easier. I'll have to go read up on how the new meters work. This has me intrigued now.

[This message has been edited by Formula88 (edited 11-06-2006).]

Electric car - Powered by Coal ®

quote Originally posted by Formula88: I've just never seen a clamp on meter for DC before. I was under the impression that they only worked on AC circuits because they measure the induction from the magnetic field around the conductor, and since the field is static on a DC circuit, there's no induction to measure. I've always used serial ammeters for DC, and used my Amprobe clamp meter for AC. Clamp on makes life much easier. I'll have to go read up on how the new meters work. This has me intrigued now.

Clamp on DC --- When you go to autozone to have your battery checked..... thats what they use.

quote Originally posted by intlcutlass: Clamp on DC --- When you go to autozone to have your battery checked..... thats what they use.

Whenever I've had a battery tested, I just hand it to the dude and he takes it and tests it somewhere.

I used to do HVAC work back in the day, and the Amprobes we had could only read AC. Been a while since I got out of that business, so I haven't really had a need to keep up with the tech. I still have that old Amprobe, and it works just as good as the day I got it. Durable little meter.

quote Originally posted by Formula88: Whenever I've had a battery tested, I just hand it to the dude and he takes it and tests it somewhere. I used to do HVAC work back in the day, and the Amprobes we had could only read AC. Been a while since I got out of that business, so I haven't really had a need to keep up with the tech. I still have that old Amprobe, and it works just as good as the day I got it. Durable little meter.

Now they don't even need to take them out of the car...

They can test the battery , and as long as thats good , they can test your alternator right after, on the car while running....

I have several DC amp clamps, unlike A/C ones they are powered by 9v batteries and need to be calibrated before use (one just push the button, the other turn a dial). I use them with my Vantage or my Picoscope all the time. I also have a Fluke A/C amp clamp... never have used it.

quote Originally posted by Formula88: Gasoline refinery - Powered by Coal ® Your point?

By the time you burn the coal, heat the water, spit steam through a turbine, convert the mechanical energy into electricity, heat the miles of wires, and step down the voltage to power your car........... I bet you'll have made 4x the pollution (CO2, what have you) and wasted 2x the energy than a gasoline engine.

You're pulling a Rube.

[This message has been edited by ryan.hess (edited 11-06-2006).]

quote Originally posted by ryan.hess: By the time you burn the coal, heat the water, spit steam through a turbine, convert the mechanical energy into electricity, heat the miles of wires, and step down the voltage to power your car........... I bet you'll have made 4x the pollution (CO2, what have you) and wasted 2x the energy than a gasoline engine. You're pulling a Rube.

yes, this is one of the sucky parts of pure electric. but, this also makes smaller local solar powered/wind power a nice option. also, "plug-in" hybrids.

also, try and picture the gasoline infrastructure is not in place. this makes for a more fair comparison. gasoline is hard to beat, because theres many many dollars invested in it already. we have big refinerires, distribution & many years of compitition to make it effeicent. if you had to rely on making your own gasoline, beleive me - you wouldnt be so happy with it.

I'll agree, pure electric, as it stands by todays standards, is not a good alternative. but, plug-in hybrids. thats a great way to go. regenerative braking. solar trickle charging while car sits in parking lot during work hours.

If the battery cells were standardised, and slot in and out...there could be recharging stations where you would drive in, and your used batteries pulled out, and a fresh set pushed in. Over and done in a couple of minutes.The batteries would never belong to you..you would just rent them. Your used batteries could be put on charge, and ready for the next customer to use in a couple of hours. Main problems with this? Storage of the expended batteries being re-charged. There would have to be many more 'filling stations' to cope with the numbers coming in.
The idea would be that you pay, for example 'Shell Batteries' a yearly subscription which would entitle you to a set of batteries.You wouldn't own them,just lease them.That would take care of The condition of each set of batteries, when they become impossible to charge again.
This is all just thinking as I type..probably totally flawed idea..but it might lead to something.
And finally, their is too much at stake for the Oil Companies to eventually hand over energy supplying to another group of companies, and just wither and die. You can bet your bottom dollar that they ar working like MAD at developing something they can switch to, to maintain their businesses
And finally If the recharging was to be done from main power grids, the pollution would be just as high before, because the generating stations would be creating vast amounts of waste over and above the level they are at the moment...
Nick

[This message has been edited by fierofetish (edited 11-06-2006).]

quote Originally posted by intlcutlass: Now they don't even need to take them out of the car... They can test the battery , and as long as thats good , they can test your alternator right after, on the car while running....

Yeah, but usually I only need one tested when the car won't start - so I take it out and carry it over in the car that will.

AC motors? More efficient?? LOL!!!! I take it that falls under the same category as "drive with your tailgate down to save gas", right?

Have you even LOOKED at an AC motor?


One (or two, maybe three, depends on the setup of the windings) speed, takes a SURGE of power to begin the cycle (much like a car engine), and takes *huge* amounts of power (between 100 and 400 watts) to drive - about 100 watts to just spin in place! The size of motor you'd need to operate a CAR would be, well... almost exactly as big as a gas car engine!

Read up on AC induction motors. Plz.
http://www.oddparts.com/acsi/motortut.htm

There are other types of motors - like those used in smaller AC applications such as clocks - but those are very bad at converting energy into motion; they're designed just to work at variable speeds but not to give a lot of force.

I dont think you understand even how an electric motor works. I can also show you mathematically that DC motors are inefficient:

Torque = x sin(2*pi*f*t) | x=some constant, f*t=angular displacement

The power required by the DC motor is constant when the commutator makes contact. Thus you are wasting plenty of juice when the rotor is at a low displacement angle. This is opposed to AC where the voltage rises with displacement and much less power is lost.

You whine about a surge current why? Are you applying the DC motor electrodynamics to AC which is nonexistent? Do yourself a favor and pick up an EE book sometime.

Anyone else notice Falcon4 is banned?


PS: the link you posted says that AC motors are more effienct than DC in all respects for power over 10hp.... Are you smoking something?

[This message has been edited by AP2k (edited 11-06-2006).]

quote Originally posted by TK: Ultimately the challenge is to get the car to go as far on a battery full of electricity as it would if it was filled with gasoline and at a decent power and top speed level. I would be happy with a car that will do: 0-60 in 7-9 seconds 350 mile range Top speed of 90MPH. 80% recharge in 2 hours. For 95% of my driving, that would cover it. I do like the battery swap idea. There are a few gotchas (you can't easily opt for some expensive/higher range batteries if you have deep pockets), but for most driving it would certainly work. But we are a far away from that. I am still guessing 20 years but I think it can be done.

I was just thinking, do we really need to be able to drive 350 miles at a time? I know personally if I was able to drive just 40 miles I'd be set, if the thing would recharge in 8 hours or less. The thing is, no one wants to fill up at the gas station every day, which is why we have large capacity tanks. But if an electric engine were able to charge on its own while we go on about our business, who would care if it needed filling every day? Yes, batteries can only take so many cycles, but you'd theoretically have less overall. And I only need to be going 65mph. Sure it's not as fun, but it makes the goal a lot more reachable. And this is for a daily commuter, not the "everything" car or the "fun" car. Hopefully as tech progresses, the "everything" car would be more feasable. I'd be happy with just the requirements I listed, if it were affordable.

quote Originally posted by kwagner: I was just thinking, do we really need to be able to drive 350 miles at a time?

Only if you want to take a road trip. It's about 600 miles from here to Orlando. So, if I wanna go see Mickey Mouse, a 10 hour drive just became an 18 hour one if I have to stop half way for 8 hours to recharge.

Now for a commuter car, you're right, 350 miles should be enough for most people, but it doesn't work as an only car. I'd love to check one out for a daily driver, as long as I still have my toys, but the revolutionary change will be when you can use one as your only car. That'll open it up to many more people.

[This message has been edited by Formula88 (edited 11-06-2006).]

quote Originally posted by AP2k: ... I can also show you mathematically that DC motors are inefficient: Torque = x sin(2*pi*f*t) | x=some constant, f*t=angular displacement ...Thus you are wasting plenty of juice when the rotor is at a low displacement angle. This is opposed to AC where the voltage rises with displacement and much less power is lost. ... Are you applying the DC motor electrodynamics to AC which is nonexistent? ... PS: the link you posted says that AC motors are more effienct than DC in all respects for power over 10hp.... Are you smoking something?

I tried to post a nice reply to this that shot just about every part of this post down in flames, but I'll give the reader's digest version. The last one was kinda lost in my clipboard when I couldn't post it.

A college degree doesn't give you experience. A college degree gives you the peace of mind that you successfully memorized a book of charts and figures - but gives you no real understanding of what goes on underneath to do what you learned happens. Basically all you did is spout out a bunch of words and equations from the book that says how motors work. You don't have experience with both, you haven't heard about both, you haven't taken apart and understood -- not just analyzed -- how each work. You just say what's in the book and you don't even know if it applies.

In this instance you're telling me that a motor which can only spin at a fixed speed is more appropriate for an electric vehicle than a DC motor. In a DC brush motor, energy is almost directly converted to motion, in much the same way as gas to fire and heat. The power drives the rotating electromagnets that oppose the fixed magnets, and spin the shaft and the commutator, switching polarity, so on and so forth. If the motor is stopped or stalled, the current applied to the electromagnets increases (according to the voltage provided) and the motor pushes harder. If it were capable of applying constant torque across all RPMs, well... it'd spin up to an infinite speed and fly apart.

AC motors? You know what? Let me just get straight to the final point, which will cover this one as well.

quote Disadvantages # Expensive speed control # Inability to operate at low speeds # Poor positioning control

Enough said. The advantages only cover how cheap they are to make.

DC motors, on the other hand?

quote Advantages # Easy to understand design # Easy to control speed # Easy to control torque # Simple, cheap drive design

quote Disadvantages # Expensive to produce # Can't reliably control at lowest speeds # Physically larger # High maintenance # Dust

While I have trouble believing "Physically larger", I don't see any disadvantage including "less efficient". Prove it -- and do it with real world terms, not "smoke screen" terms that one EE says to another to increase the size of their ego.

edit: Also, that page does not say AC motors are more efficient than DC motors above 10 HP. In fact, it says:

quote ...AC inverters and AC motors are usually more cost-effective than DC motors and DC drives for applications larger than about 10 horsepower, because of cost savings in the AC motor.

Bold added for emphasis.

[This message has been edited by Falcon4 (edited 11-06-2006).]

quote # Expensive speed control # Inability to operate at low speeds # Poor positioning control

quote ...because of cost savings in the AC motor

1: Speed control is a non issue because after 10 hp, the cost/hp begins to decrease. Honestly, do you think manufacturers are going to mass produce cars with less than 10 hp?

2: Low speed in the Tesla, et al is covered by a first gear.

3: Position control is a completely non-issue simply because we are driving a car, not picking cokes out of a vending machine.

[This message has been edited by AP2k (edited 11-06-2006).]

Nice job totally missing the point. You'd do great in Iraq - that is, if you can dodge bullets just as well as you dodge the point... plus you fit John Kerry's model as well.

No use trying to reason with you... wonder if anyone else wants to give it a shot?

quote Originally posted by kwagner: I was just thinking, do we really need to be able to drive 350 miles at a time? I know personally if I was able to drive just 40 miles I'd be set, if the thing would recharge in 8 hours or less. The thing is, no one wants to fill up at the gas station every day, which is why we have large capacity tanks. But if an electric engine were able to charge on its own while we go on about our business, who would care if it needed filling every day? Yes, batteries can only take so many cycles, but you'd theoretically have less overall. And I only need to be going 65mph. Sure it's not as fun, but it makes the goal a lot more reachable. And this is for a daily commuter, not the "everything" car or the "fun" car. Hopefully as tech progresses, the "everything" car would be more feasable. I'd be happy with just the requirements I listed, if it were affordable.

I get what you are saying. For most driving 40-80 miles on a charge would cover lots of people (work commute) but we drive long distances regularly so for the electric car to be viable as a *full* replacement for a gas car it would need to cover 300+ miles and be ready to do it again as fast as possible. If I had to hang out for dinner somewhere to get 80% of the range back (say a Sacramento to LA run), I'd live with it!

And then you drag *affordable* into it!

*cough* one of the neat little paragraphs of Prop 87's 12,000 words (or whatever the hell "No on 87" said) is that it will provide people with a program that pays you the difference between an electric car's price and a comparable gas powered car's price. So if that $250,000 Tesla is too expensive for you, pay for whatever the hottest typical sports car is (what, $80,000?) and it's yours. And yeah, I ended up going over the whole freakin' thing.

... That is, if the damn thing passes. Because of a nice ****-up in the nitwit that registered me to vote, I don't get to vote on it. So all I can do now is tell other people to.