08-14-2008, 09:45 PM
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#11 (permalink)
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Mad Scientist
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Nerys,
I work on HEV's at Ford for the last 10 years. There is no cheap way to do it on the cheap. If there was a way, we would be all over it. The 230V eBay motor are made to run at a constant speed, at some fraction of the field speed, which is 60 Hz. the only way to slow down the theoretical vehicle would be to use a brake, not the most efficient. If 7.5 kW generator was your only source of power, you 0-60 acceleration time would be "same day" Seriously, it would
take 3+ min to reach 60 mph. It would be difficult to have any kind of safe dirveability w/o batteries. the lowest cost option is to buy a used EV: EV Tradin Post: Electric Vehicle Classifieds
and put a generator and a charger on board, basically a low tech volt.
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08-14-2008, 10:22 PM
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#12 (permalink)
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Grrr :-)
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You consider that cheap? I can not afford to buy the parts to make an EV and a used EV is even more expensive than the parts to make an EV !!!
I was wondering about those 230v ebay motors. :-( I guess I am just going to have to go back to the making my minivan a partial EV hybrid mix thing. The only thing really stopping me is finding a damned motor Grrrr :-(
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08-14-2008, 10:43 PM
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#13 (permalink)
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Mad Scientist
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08-14-2008, 11:01 PM
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#14 (permalink)
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Grrr :-)
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$1500 !! that sucks :-( I am still hoping to stumble into one of those junkyard forklifts :-) hehe I mean $1500 is downright cheap but so much more than I can afford just now :-( its coming though. The patent expires 2015 You watch and see how the EV market explodes when that happens.
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08-14-2008, 11:11 PM
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#15 (permalink)
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Mad Scientist
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If EEStor product turns out to be true, THAT will change the EV market. The engineers there claim a 3X w-hr /Kg of Lithium = 360 wh/Kg in 350 volt cell!!, charge / discharge and durability characteristics of a capacitor. But, well see the data when it arrives next year.
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08-14-2008, 11:23 PM
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#16 (permalink)
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Grrr :-)
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I know !! I am praying and DROOLING over the potential of this technology! I just pray that EEStor realizes they can make a LOT more money by changing the world than by selling out!!
What more important though is not power density or mass. WE DO need to get it down to some X mass thats not too heavy (leads are too heavy)
Power Density is not as critical is mass is light and most importantly
the most critical aspect.
CHEAP PRICE. If they can get the EQ of say the E95 pack down to say $500 a pop. The world will change.
I could put a $5000 pack in my big van and go 1000-1200 miles without a charge.
What we need is a rediciously affordable and long lasting battery pack. Low power density is ok if its light enough. If they can do high power density at the same time. Great bonus!
What we need is a 150mile range 4 door 4 person mid size family sedan for under $12k
THATS what we need. WHen we can do that you will see a MASSIVE shift to electric cars.
Know what a $12k electric car would cost me? NOTHING. thats because the monthly payment on a $12k loan is smaller than what I am spending RIGHT NOW ($350) monthly on gasoline!
but it has to be a 100% replacement. for me that means a DROP DEAD worst posible range of 75 miles. My commute is 55 miles each way. 20miles buffer would make me feel safer. Drive to work. Charge up Drive home.
75miles range would allow me to not use gasoline for over 95% of my yearly driving.
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08-15-2008, 09:00 AM
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#17 (permalink)
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Mad Scientist
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Nerys,
We wont get to the $12k electric car without going through a few generations, and energy storage must fundamentally change. EEStor may have the solution. Time will tell.
In order to get to $12k electric car using what we have today, some compromises must be made, like range OR performance, you cant have both. Most people (outside of this forum at least) are not willing to make these compromises. Wars and politics have kept oil quite cheep for a long time, and has effected the long term choices they have made.. I think that $4.00/gal is too cheap to get people to compromise. Not to be mean, but if fuel was always north of $4.00/gal , would you live 55 mil from work and have the cars you do now?
I have to disagree with you on some points, mass and power are important. Pb-A are cheap, but 50 w-hr/Kg is unacceptable and they wear out too fast. Ni-MH works quite well, 80 w-hr/Kg and super durability, but there are legal issues with a cell >15 Ah (F!@kin thanks Texaco-Ovonic) and they need a good cooling system for charging. Li-Ion dont have the legal issues, 120 w-hr/Kg is quite good, but cost is high. Even mass manufactured commercial off the shelf (18650 size laptop cells) cost come in $500/kw-hr, pretty high, considering that a nice sealed AGM deep cycle Pb-A cost $202/kw-hr.
A typical EV conversion uses 250 wh-hrs / mile. 70 mile range = (70 mi * 250 250 wh-hrs / mile ) = 17.5 kW- Hrs = (7.5 kW- Hrs*$202/kw-hr) = $3535 Pb-A pack and the battery will be dead in 300-400 deep cycles.
The Volt has a 16 kW-hr Li-Ion pack, of which 8 is usable for good durability.
pack cost for the volt? 16 kW-hr*$500/kw-hr = $8000. Even if they get a sweet deal of $400/kw-hr, the pack would cost $6400. This is why i thing that the battery must fundamentally change if your goal is $12k electric car.
What the more likely scenario is $10+/gal for fuel, making a $35K volt look cheap.
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08-15-2008, 11:31 AM
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#18 (permalink)
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Master EcoModder
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just to give you a idea of what you are looking at, my 1,400 pound electric car draws around 6,000 watts cruising at 35mph on a flat road, 12,000 - 15,000 going up hills at 25mph, and up to 20,000 for a few seconda while starting from a dead stop and 25,000 watts going up my 300 foot long driveway, all of this in a 1,400 pound car with 500 pounds of lead acid batteries.
you don' need alot of range out of the battery, but you do need one large enough that it can handle the draw, I would almost say that normal car batteries are going to be the way to go, as they are going to get charged right back up after you use the burst of energy, 500 cold cranking amps would give you about 6,000 watts, and if you had ten of them that is 60,000 watts of avalible power.
but I personnely think you are better off moving or changing jobs if you spend $350 a month on gas.
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08-15-2008, 11:47 AM
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#19 (permalink)
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Quote:
Originally Posted by Nerys
I would love too but a 230v battery pack is prohibitively expensive and HEAVY.
thats 20 lead acid batteries! (ouch) even if I could find 24v batteries thats still 10 of them.
Unless there is a way to CHEAPLY and EASILY use a lot less than 20 batteries to get 230v ??
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Not sure what you're getting at here, batteries are DC and the 230v you keep getting at is the AC power from your generator, and the AC power required by the traction motor. You don't need a 230 VDC bank of batteries to run a 230 VAC generator. You will however need an AC/DC converter to charge the batteries and a DC/AC inverter to power an AC motor, or switch to a DC motor and run it straight through a motor controller.
If you can't afford the parts or don't expect to be able to in the near future then you can plan the project and dream about it, but don't get too excited over it not being exactly what you want.
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08-15-2008, 12:11 PM
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#20 (permalink)
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Administrator
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Quote:
Originally Posted by Ryland
but I personnely think you are better off moving or changing jobs if you spend $350 a month on gas.
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At the very least spend $2k and get yourself a small car for commuting! You'll half your gas prices and the car will have paid for itself in the first year!
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