914 EV discussion, Who's doing or done an electric 914? Options

[Joe Bob]

http://www.electroauto.com/gallery/vp914.shtml
http://electric914.wordpress.com/
http://www.evcl.com/914/

Electro Automotive has a kit for 14K...yikes.....
Otmar seems to be REAL busy building components.....

I'm thinkng of doing one for my twins..... (IMG:style_emoticons/default/blink.gif)
I have two years to get it done.....

[Joe Bob]

http://www.kta-ev.com/catalog/index.html

This seems to be a better way to go.....

[smontanaro]

Lots of people have done 914 EVs. Here are some links:

• http://914ev.blogspot.com/
• http://groups.google.com/group/914ev
• http://evcl.com/914/
• http://www.evalbum.com/type/PORS

Skip Montanaro

[banger]

It all depends what you are looking to get from a conversion. An AC drive system is the most efficient. DC will give you more torque and HP. DC will have a more limited range than an AC system. It also depend what your motive is for converting as well. Electric vehicles arent very cost effective when it comes to driving. Currently lead acid batteries are a lousy way to power a vehicle. They are too heavy, and have a very limited lifespan. Nimh works well, but are difficult to get. Li-ion works very well, but needs careful battery management.

[racunniff]

Lots of people have done 914 EVs. Here are some links:

Skip Montanaro

Mine: http://volt914.blogspot.com

[pjf]

I'm restoring a '76 914 intending to convert it to electric. I've been kicking around the AC/DC question while I'm welding and have come to the decision that DC is the only way to go. AC is more efficient than DC but only slightly so. You do get regenerative braking with AC but again the gains are not that great (like 10%). There is really only one anywhere near affordable AC system for the 914 and that's the one used by ElectroAutomotive AC kit. Unfortunately it delivers about half the horsepower of the 914 gas engine and the car weighs about twice as much after the conversion. You are supposed to get more range with an AC system but with amount of electricity used quotes I've seen I'm doubtful. With DC you have more options, horsepower, and torque. You can match or exceed the horsepower and torque of the original engine. I'm looking at a Zilla controller (from Otmar) and a WarP motor right now as the best options. As far as lead acid batteries go, yes they are heavy and they don't last forever (2-3 years) but they are the best we have right now and they can be used to make an electric car with decent performance and range. All the other options are just too expensive right now. As far as costs go, the parts are expensive but will last (except for the batteries) pretty much forever. The motors for instance (with brushes replaced) will go a million miles. Once you get past the price of the conversion parts the actual cost of batteries and electricity I work out to be less than $3/gallon gas.
If you have any question or want to discuss this further, I'd be glad to.

P.S. That avatar is going to be hard to look at alot dude.

[banger]

You may want to look the the ford ranger ev motor that is on ebay. For $2000 the price isnt bad. The nice thing about the AC motors is that they have nice flat torque from 0-4000 rpm, and typically have a top speed of 12-13,000 rpm. As for batteries, there are some sources of Nicd cells which work quite well. As for the cost effectiveness, a 914 that gets 30mpg costs 10 cents per mile with gas costing $3/gallon. If you use lead acid batteries on a 914, you would probably get around 50 miles per charge. If you figure a battery cost of $3000, and around 300 cycles, then the cost per mile for just the batteries is 20 cents. Add to this the cost of recharging at around 3 cents per mile, and you are up to 23 cents per mile. This ends up being far more expensive than driving the gas version. If you are able to use a better battery technology, then you can get the cost down. The Nimh batteries used in the EV-1 and RAV4-EV have a life of around 100,000 miles, which makes the cost of operating them much lower. A Nicd or Nimh pack may cost double or triple the cost, but will last more than three times longer. It just a bit hard to get over the initial sticker shock of the batteries.

[smontanaro]

You may want to look the the ford ranger ev motor that is on ebay. For $2000 the price isnt bad.

Except as I recall it doesn't come with the inverter which is NLA, which makes the motor pretty much worthless.

Skip

[smontanaro]

Unfortunately it delivers about half the horsepower of the 914 gas engine and the car weighs about twice as much after the conversion.

The horsepower ratings on electric motors are continuous. The ratings on gas engines are peak HP.

Skip

[Joe Bob]

The Auto Electric "kit" claims 100-150 miles on a 144 volt system using the AC motor.....but at $15K, they can bite my ass.

My office has charging stations...free fuel.....I can get a roller for next to nothing, I've done 15+ restorations on the 914s.....if I can get a reasonable load of AC/DC ideas and equipment for around 5K, I would think it would be a fun project.

My daughters would have a cheap reliable ride to school and I'd be the only guy on my block with one...

[banger]

The inverter is just a siemens Simovert, which can be purchased from Metricmind. The AC motors are pretty much all the same, you could use an inverter from Siemens, Brusa, or Azure Dynamics.

You may want to look the the ford ranger ev motor that is on ebay. For $2000 the price isnt bad.

Except as I recall it doesn't come with the inverter which is NLA, which makes the motor pretty much worthless.

Skip

[pjf]

I have to respectfully disagree with Banger's estimate of the cost per mile for an electric 914. The price of 20 6v lead acid batteries is more like $2000, not $3000. They are rated at 550 cycles at 80% degree of discharge which works out to $3.63 per charge. The pack will hold about 18kwh of electricity at .15/kwh equals $2.70. Total cost $6.33 for about 60 miles or $.1055/mile. Gas at $3 for 30mpg is $.10. Any estimate has some slop in it but I think electric cars using even low-tech batteries are now cost-effective.
The problem with the Ranger EV motor is that the converter is expensive and it runs at a much higher voltage. Higher voltage battery packs are more expensive.
I really doubt ElectroAutomotive's estimate of 100-150 miles. From the electricity usage numbers I got from someone running a car with the kit, it doesn't add up. AC systems are not that much more efficient. $15K for the ElectoAutomotive kit is steep, too steep for me. A DC system where you do things like build the battery boxes yourself can save you alot. I think the estimate is more like $8K. I haven't added up what I'll be spending but its not $15K I can tell you that.
I know that electric motors are rated with continuous HP rather than peak as is the case for gas engines but half the horsepower continuous is still not enough. I've asked someone who used the AC kit in a 914 and they agree. The flat torque curve is nice but it can't make up for the lower horsepower it would seem. DC motors can and are abused and in the extreme case racers get over 400hp from the 9" motor that I plan on using. I'm not going to go that far and with Otmar's controller are shooting for more like 200hp for short bursts.
I too think this will be a fun project. Good luck and let me know if I can help with anything.

[pjf]

Looking over my last post I realized I messed up the HP comparison. The AC motor used in the ElectroMotive kit generates half the PEAK horsepower not half the continuous horsepower. The continuous rating is in the 20's. You can get a peak HP rating of electric motor for a easier comparison to a gas engine. The EV1 used 2 of the motors equivalent to the one used in AC 914s too.

[smontanaro]

The horsepower rating for an electric motor is also tied to a specific input voltage, e.g.:

http://www.diyelectriccar.com/forums/showt...-144v-4333.html

Skip

[Joe Bob]

I have to respectfully disagree with Banger's estimate of the cost per mile for an electric 914. The price of 20 6v lead acid batteries is more like $2000, not $3000. They are rated at 550 cycles at 80% degree of discharge which works out to $3.63 per charge. The pack will hold about 18kwh of electricity at .15/kwh equals $2.70. Total cost $6.33 for about 60 miles or $.1055/mile. Gas at $3 for 30mpg is $.10. Any estimate has some slop in it but I think electric cars using even low-tech batteries are now cost-effective.
The problem with the Ranger EV motor is that the converter is expensive and it runs at a much higher voltage. Higher voltage battery packs are more expensive.
I really doubt ElectroAutomotive's estimate of 100-150 miles. From the electricity usage numbers I got from someone running a car with the kit, it doesn't add up. AC systems are not that much more efficient. $15K for the ElectoAutomotive kit is steep, too steep for me. A DC system where you do things like build the battery boxes yourself can save you alot. I think the estimate is more like $8K. I haven't added up what I'll be spending but its not $15K I can tell you that.
I know that electric motors are rated with continuous HP rather than peak as is the case for gas engines but half the horsepower continuous is still not enough. I've asked someone who used the AC kit in a 914 and they agree. The flat torque curve is nice but it can't make up for the lower horsepower it would seem. DC motors can and are abused and in the extreme case racers get over 400hp from the 9" motor that I plan on using. I'm not going to go that far and with Otmar's controller are shooting for more like 200hp for short bursts.
I too think this will be a fun project. Good luck and let me know if I can help with anything.

Do you mind posting what the the motor, inverter, controller ran price wise and what manufacturer did you choose and why you went that way? If you'd rather you can email me 356@cox.net.

On shifting? Do you shift thru the gears or do you simply use 3rd or 4th and just tromp on it?

I see plans that use a clutch package, if it's a direct drive with a forward and reverse gear...why the need for a clutch? I've seen schematics for golf carts and such that don't use any clutch at all....

The charging stations at our office have 2 different style plugs....I assume due to manufacturer's choice, Beta versus whatever....do you plan on home charging or is there a "Public Charging" station format?

[Joe Bob]

Further.....are NiMH or Li batteries available in the car battery format?

[geniusanthony]

I too have been kicking this idea around lately. My plan was to keep the teener as a gasser but find a lotus 7 replica for EV. To really exploit the advantages of electric one needs minimal weight.

I have messed around alot w/electric RC planes and although the cost seems high the power to weight of a brushless and LIpo package is incredible, and effiecient , and reliable.

Whatever method one chooses the amount of juice available dictates how well it'll go. For example, the Tesla literature tells us that 200KW is what it takes to make a sporting EV. Batteries are the biggest drawback it seems.

There was a guy who parted a wrecked Prius for a supply of NiMH packs. Found him somewhere in the locostusa.com forums certainly lighter than lead, but as Mike asked about a car battery format...is that what you would want...awfully big and bulky vice other methods.

Sorry I can't be more helpful as I have only a casual understanding of whats involved.

[neo914-6]

You really need a higher no cost goal to go electric since the car and conversion will cost ~15k. After a decade of continuous gas saving you'll need to use that savings for battery replacement. Until component costs come down and better battery technology comes available, you will be a pioneer an part of a movement and statement against oil consumption. More demand will eventually increase manufacturing and lower these costs. I applaud all those who took the first steps and invested in this movement... (IMG:style_emoticons/default/clap56.gif)

Current 914 owner/builders:
• Otmar, Otmar CA 74 two 8" Advanced DC motors, Zilla cntrllr
• sgomes, Shannon CA 73 Electric 120Volts, a Zilla cntrllr
• stwspoon, Stan CA 75 9" Advanced DC motor, 114V w/Curtis cntrllr
• TimK Tim OR 144 volt AC kit
• PThompson509 Peter CA
• Racunniff CO 144 volt AC kit
• Mike914 Mike CA http://www.roadglue.com/forum/showthread.php?t=62

http://www.914world.com/bbs2/index.php?sho...c=79279&hl=
http://www.914world.com/bbs2/index.php?sho...c=74919&hl=
http://www.914world.com/bbs2/index.php?sho...c=74743&hl=
http://www.914world.com/bbs2/index.php?sho...c=74586&hl=
http://www.914world.com/bbs2/index.php?sho...c=73178&hl=
http://www.914world.com/bbs2/index.php?sho...c=69980&hl=

If GM does what they plan, you can buy a Volt in a few years.

[Zundfolge]

I wouldn't be interested in an electric 914 unless it could compete with the Tesla performance wise.

http://www.teslamotors.com/

Too bad the Tesla is so darn expensive.

[banger]

The price on Trojan T-105 batteries are around $150ea. This gives a pack cost of $3000 for 20. You could go for cheap wal-mart golf batteries, but then you get what you pay for. As for charging, the Trojans are rated at 220ah multiply this by 120v, and you get 26kw. Then take 80% of this and you have 20kw, now divide by the charger efficiency 94%, and you end up with 21.3kw. Multiply this by .15/kwh, and you get $3.15, then divide 50 miles, and you get 6.3 cents per mile for just the power.

The other problem has to do with the cycle life. If you have good batteries, and limit the depth of discharge, then you will get more cycles. But you also have to remember that the capacity is still declining with each cycle. Lead acid batteries last between 300 and 500 cycles. At this point you will be down to 50-60 percent of initial capacity. To prevent further damage to the battery, they should only be discharged to 80%. If you drive the vehicle every week day, and use only 1 cycle per day, then your batteries will last 18-24 months. If you drive it every day, then the time will be less. Also keep in mind that the batteries will decline with age whether they are used or not. The will also need to be charged as soon as they are used, since letting them sit will result in sulfation.

And for some background, I currently own 2 electric vehicles, and owned 2 others prior to the current ones. I have owned a 48V dc powered car, 120V DC powered truck and two 312v AC powered trucks. I can tell you all the ins and outs of owning and driving electric vehicles. My daily driver is 98 Ford Ranger EV, which gets driven around 30-40 miles per day.

I have to respectfully disagree with Banger's estimate of the cost per mile for an electric 914. The price of 20 6v lead acid batteries is more like $2000, not $3000. They are rated at 550 cycles at 80% degree of discharge which works out to $3.63 per charge. The pack will hold about 18kwh of electricity at .15/kwh equals $2.70. Total cost $6.33 for about 60 miles or $.1055/mile. Gas at $3 for 30mpg is $.10. Any estimate has some slop in it but I think electric cars using even low-tech batteries are now cost-effective.