One for the EV fans

cobb

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I could ramble on forever on EVs. Last I read I thought NICADs were best as they can be charged quickly like for regen braking? Of course they can handle abuse like from DUMP charing and fast drain.

They were going to use flywheels, but if it was mounted one way, the car would not climb a hill and if the other orientation it would not steer. /ubbthreads/images/graemlins/smile.gif
 

James S

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Cobb, I remember reading about those flywheels too. The article made a big deal about the fact that they needed to operate in a vacuum and there were pictures of what happened to them if you got a leak. Energetic disassembly doesn't quite do it justice /ubbthreads/images/graemlins/wink.gif I don't remember realizing what the gyroscope effect would do to the handling of the car, thats hilarious!

350km to a charge, and we know from other threads that you'll have to replace the LiIon packs in 500 charges or 2 years or there abouts. Thats 180,000km or 111,847 miles... Thats more than most folks drive in the 2 or 3 years that the pack will last. Anybody care to hazard a guess what a new battery pack would cost? Then we can figure out how much it costs to drive /ubbthreads/images/graemlins/smile.gif
 

gadget_lover

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It's funny that NiMH has a similar charge cycle limit, but.... It has a longer shelf life. Toyota leveraged the fact that it will take many, many more partial discharges and still work well. The Prius Hybrid will almost never drain the battery pack. In 2 years mine's never come close. They predict 150K miles and 7 years between battery changes.



The flywheels were a great idea. The use of gimbals fixed the gyroscope effect. I don't know if they ever found an acceptable way to handle the destruction of a shattered flywheel. They did one with carbon fibre that became a black tangle of thread when it broke, but that was too expensive.

Daniel
 

idleprocess

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Carbon fiber flywheels tend not to destroy things (and people) when they experience catastrophic failure. They have the requisite mass, but they desintegrate upon failure, rarely damaging the housing.

I'd think they could mount the flywheel on a vertical axis, which would only make changes in the car's angle in the X-Z (roll) and Y-Z (pitch) planes against gyroscopic forces. X-Y (steering) forces are against the axis, so the flywheel shouldn't adversely effect handling.

Of course, I remember when "flywheel batteries" were the NEXT BIG THINGtm. They were going to be somewhat larger than a car battery, only they'd store more kinetic energy that would convert to electricty than a chemical battery. I guess they were supposed to use some magic frictionless passive-magnetic bearing and be literally suspended in a vacuum to work their miracles. Dunno how long they were supposed to hold a "charge," but I think they had some troubles outside of the lab - gyroscopic forces being a major nut they probably couldn't crack for something that small potentially in motion... ...and the magic frictionless bearings and vacuum housing.
 

udaman

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[ QUOTE ]
James S said:

350km to a charge, and we know from other threads that you'll have to replace the LiIon packs in 500 charges or 2 years or there abouts. Thats 180,000km or 111,847 miles... Thats more than most folks drive in the 2 or 3 years that the pack will last. Anybody care to hazard a guess what a new battery pack would cost? Then we can figure out how much it costs to drive /ubbthreads/images/graemlins/smile.gif

[/ QUOTE ]

Do not confuse mass production cell phone/laptop batteries with other application specific long-life industrial Li-Ion designs: ECN- Lithium-ion Batteries Charge Ahead

Follow up article referenced in link above:

battery power management circuits
http://www.reed-electronics.com/ecnmag/article/CA379290
 

James S

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[ QUOTE ]
Carbon fiber flywheels tend not to destroy things (and people) when they experience catastrophic failure.

[/ QUOTE ]

The failure pictures I saw were a LONG time ago. The flywheel was fiberglass and also turned into a mess of fibers but took the housing along with it. You'd want some mass in the flywheel wouldn't you? Or it wouldn't store much power.

Isn't there a new truck that uses hydraulic fluid under pressure to store power now? It pumps up a huge pressure during breaking or just idling which you can then use to jump off the starting line regardless of your load.

udaman, I didn't mean to put them down. I love LiIon batts. without them I'd have about a 30 minute runtime on my laptop /ubbthreads/images/graemlins/wink.gif Thats an interesting article. My only problem is that I don't see any of those cells in any production equipment yet. My laptop cells are still the old cylindrical ones and not all that impressive an Mah rating compared to what is possible, and yet I still feel like I pay a big premium for them. but since the car companies have pretty much abandoned the idea of a battery operated car i guess that won't be the application that pushes the technology. Which is a shame.
 

Darell

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What! You mean you guys are interested in EVs? Cool! I should first point out that the ACP Tzero is faster, cheaper and has been available for many years. Where's the interest?!

Couple of things on what I've just read here:

1. Prius batteries are NEVER allowed to discharge. Nature of the beast. The batteries are kept between 50% SOC and about 80% SOC IIRC. They will last WAY beyond 150k miles. I know this because the Rav uses the same batteries, and the Rav goes from 100% SOC down to below zero... and the batteries have already lasted over 150k miles in several instances.

2. Li-Ion batteries (as has been pointed out) have far greater than 500 cycles in them. If managed correctly, any modern battery technology will last the life of the car. Rarely are the small batteries in cell phones or laptops managed for optimum life. The Li-Ion Tzero has almost 500 cycles on it now, and it still has the capacity for 300 miles range - and 0-60 in 3.6 seconds!

3. All modern battery chemistries can be charged pretty damn fast. We're hobbled by what the industry has given us for now... but the charge curcuit for both the EV1 and the Rav4EV are capable of 50kw - while both were/are limited to 5kw charge rate.

OK, so here I am, ready to go. You guys been to my EV site lately? Lots of new stuff to dig around in and cause controversy. /ubbthreads/images/graemlins/smile.gif
 

cobb

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Using an electric wheelchair I follow up on this stuff. I use 2 deep cycle group 24 batteries and get a days worth of run, an estimated 6 miles at 6mph.

Charging is another issue. Most circuits are limited to 1500 watts and that may trip a breaker at a continious rate. Then there is the question if the grid can handle cars in addition to AC, heaters, computers and other gizmos? I believe it will be cheaper than buying gas. Hell, splitting water to hydrogen is cheaper than gas, plus everyone has both water and power to do so. You know you can run a car on hydrogen right off the bat? BMW has a dual fuel car already out there and many have converted their cars over using the same ICE engine.
 

Darell

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[ QUOTE ]
cobb said:
Using an electric wheelchair I follow up on this stuff. I use 2 deep cycle group 24 batteries and get a days worth of run, an estimated 6 miles at 6mph.

[/ QUOTE ]
Man... we've got a couple of guys in electric wheelies around here who almost keep up with city traffic! I swear they can do almost 20mph. Doesn't look safe to me! But what do I know? I ride a bicycle in traffic too. /ubbthreads/images/graemlins/smile.gif

[ QUOTE ]
Charging is another issue. Most circuits are limited to 1500 watts and that may trip a breaker at a continious rate.

[/ QUOTE ]
Full-size EVs will not (normally) charge on a standard 110V household outlet. Would take too long for one thing. 220/40A minimum. With more voltage and current, fast-charging is easily accomplished.

[ QUOTE ]
Then there is the question if the grid can handle cars in addition to AC, heaters, computers and other gizmos?

[/ QUOTE ]
Not an issue. Most EV charging is done at night, off peak when we're *wasting* power by having the generators idle. Fact of the matter is, power would be cheaper for *everybody* if we had tons of EVs being charged at night. If the EV guys pay for the power that it otherwise wasted (like I do - or DID before my solar array went up) then the overall price/kWh would be substantially reduced for everybody. This isn't theory, but reality, straight from the guys who supply the power in CA, and who have the largest fleet of EVs in the world.

[ QUOTE ]
You know you can run a car on hydrogen right off the bat? BMW has a dual fuel car already out there and many have converted their cars over using the same ICE engine.

[/ QUOTE ]
Yup, we have H2 ICE... but the problem still remains - we have no way to fuel them. And making the H2 is turning out to be as dirty as burning gasoline directly. Yeah, we can make H2 cleaner... but why bother when it takes so much more electricity than simply charging batteries? /ubbthreads/images/graemlins/icon3.gif
 

IlluminatingBikr

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Darell do you have any details on this ACP Tzero that you speak of? Are they available for purchase in the US?
 

idleprocess

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[ QUOTE ]
Darell said:
Yup, we have H2 ICE... but the problem still remains - we have no way to fuel them. And making the H2 is turning out to be as dirty as burning gasoline directly. Yeah, we can make H2 cleaner... but why bother when it takes so much more electricity than simply charging batteries? /ubbthreads/images/graemlins/icon3.gif

[/ QUOTE ]
A hydrogen ICE? Remind me to stay a few city blocks away from any hydrogen-burning vehicles on the road.

Gaseous hydrogen is one of the most volatile fuels in existence. It's also very difficult to seal properly since H2 is the lightest gas.

Disgustingly hazardous. Considering your aversion to octane, Darrel /ubbthreads/images/graemlins/evilgrin07.gif
 

udaman

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Click on links provided by Darell's EV page (in his sig line) under "links" page, for more info on Tzero, EV "new" VW Beetle & Golf, ACPropulsion website

You'll have to excuse the lack of proper references by Darell, he's a n00b, ya know /ubbthreads/images/graemlins/wink.gif

Li-Ion cell phone or laptop batteries are not designed to last more than a few years, as are many consumer products. Cell phone sales are down, cost of battery replacement is an inducement to buy a new cell phone with more 'features' that you probably don't need or will not use very often.
 

Darell

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[ QUOTE ]
idleprocess said:
[ QUOTE ]
Darell said:
Yup, we have H2 ICE... but the problem still remains - we have no way to fuel them. And making the H2 is turning out to be as dirty as burning gasoline directly. Yeah, we can make H2 cleaner... but why bother when it takes so much more electricity than simply charging batteries? /ubbthreads/images/graemlins/icon3.gif

[/ QUOTE ]
A hydrogen ICE? Remind me to stay a few city blocks away from any hydrogen-burning vehicles on the road.

[/ QUOTE ]
No more dangerous than an H2 FCV, certainly.

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Gaseous hydrogen is one of the most volatile fuels in existence. It's also very difficult to seal properly since H2 is the lightest gas.

[/ QUOTE ]
No doubt. But in may ways, gasoline is far more dangerous to the consumer - and it is largely ignored. Being heavier than air, the gasoline vapors in your garage pose a larger threat than escaping. H2 dissipates far quicker by comparison.

Anyway, you don't need to convince ME of the H2 hurdles! Really - no need for debate here!
 

Darell

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[ QUOTE ]
IlluminatingBikr said:
Darell do you have any details on this ACP Tzero that you speak of? Are they available for purchase in the US?

[/ QUOTE ]

Here is info on the original Tzero with PbA batteries. Too slow.

Here is the press release for the Li-ion Tzero.

Here is the Tzero beating a 500 HP Dodge Viper in the quarter mile. Hokey video, but the facts are indisputable. The Tzero is faster in the quarter mile than any street-legal production vehicle ever produced.

Here is the ACP home with a bunch of info, including how they won highest marks in the Bibendum last year.


Bear with me, I'm still learning the ropes around this crazy forum!
 

cobb

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Ive followed hydrogen and it seems its safe. Its so light it floats away when its released and seen tests where cylinders are shot at and nothing occurs. The gas escapes faster than it can burn.

20mph wheelchair? Wonder how controllable it is indoors in tight settings?
 

Darell

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[ QUOTE ]
cobb said:
Ive followed hydrogen and it seems its safe. Its so light it floats away when its released and seen tests where cylinders are shot at and nothing occurs. The gas escapes faster than it can burn.

[/ QUOTE ]
Well, heck - you could shoot at a tank of gasoline with no ill effects too - as long as the tank was armored enough. Yes, H2 disperses rapidly, and is far lighter than air, but it most certainly CAN be ignited. When lit, the flame is invisible. The first indication that you've walked into an H2 flame will likely be that your hair is on fire. For FCV use, these tanks will be compressed to 9k - 12k PSI. I don't care WHAT the hell you've got in there, at those compressions, it is dangerous! Even air or water at those compressions gives me the willies.

[ QUOTE ]
20mph wheelchair? Wonder how controllable it is indoors in tight settings?

[/ QUOTE ]
Dunno, but it sure sounds like fun! The guy I see regularly is controlling it with his teeth.
 

IlluminatingBikr

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I'm not sure if any of you are familar with this technology, but I heard somebody invented some sort of a "hydrogen spounge." It would suck up the hydrogen just like a normal spounge does with water, and would allow you to store more hydrogen gas than normal, at air pressure.
 

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