Electric / hybrid 240z

[sleepyzzz]

i for one, am very impressed with your work, and wonder if you have thought of going into a refurbishing business and making some serious money off of this? or maybe offering all of the needed parts with instructions on how to install.

if a solar panel was added to this system, to constantly recharge the batteries from the sun as you drive, or even parked,make this more user friendly for those of us that travell in our work? i know it would ruin the looks of the car to have something on the roof,hood,or back glass, but then again, it could be laying in the rear catching the sun's rays coming thru the glass.

on average i run about 300 miles per day in my sales calls, and i have not seen anyone boasting that kind of mileage out of electrics yet. filling up forty to forty five dollars per day in gas, is taking all of the fun out of my job.

[MikeW]

if a solar panel was added to this system, to constantly recharge the batteries from the sun as you drive, or even parked,make this more user friendly for those of us that travell in our work?

If this were that simple I'm sure it would have been done before. Photovoltaics on a car like this charging the batteries all day long in bright sunlight might get you a few hundred feet of driving. The solar powered cars you may have seen driving across Australia tend to be extremely light and aerodynamic with room for only a driver and a huge surface area of PV cells.

[jmead]

I gotta hand it to ya kid, you're doing a great job. Two things:

1) You *gotta* bring this car up to a show in Syracuse or Rochester this summer. I have to see it in person :-)

2) What's your budget for this project and by what % do you think you'll exceed it? ;-)

1) If the "auxiliary power unit" is done by then it would make a fun day trip, though I still have a lot of work left before its show quality.

2) I've been keeping a detailed log of all my expenses and I'm at a little over $6k in the car right now, including another $1k for the generator parts yet to be installed. My budget is pretty much "how much money can this car save me over the next few years?". I have increased that figure several times when choosing higher end components with the justification that if I build the car right it will work reliably for many years and ultimately save me more than my investment in gas.

I spend $2-3k a year on gas (at $3/gallon, those days are gone) alone, so over my 4 years of college it will pay for itself. After that point I have essentially a free car that just needs new batteries every 4 years. I spent $2300 for a pack of the absolutely highest performance lead acid batteries available, and I could have gotten some cheap flooded batteries for less than $1000. The major components (motor and motor controller) should last for 20+ years.

The more I did the math the more I realized I couldn't afford not to build an EV.

[jmead]

i for one, am very impressed with your work, and wonder if you have thought of going into a refurbishing business and making some serious money off of this? or maybe offering all of the needed parts with instructions on how to install.

Thank you. Honestly every time I look at it I can't believe I built it. I've put more time and energy into this project than anything I have done.

I have been thinking constantly about the potential to make a business out of this. I've been getting so much attention recently its really making me think it might be possible. I have another datsun, a 76 280z, and I may convert that and see if there are any takers. Sell it on ebay motors perhaps?

if a solar panel was added to this system, to constantly recharge the batteries from the sun as you drive, or even parked,make this more user friendly for those of us that travell in our work? i know it would ruin the looks of the car to have something on the roof,hood,or back glass, but then again, it could be laying in the rear catching the sun's rays coming thru the glass.

This was the focus of a long brainstorm session not too long ago. My conclusion was that it would work, but it wouldn't provide enough energy to warrant the investment. I could fit at most 300 watts of panels on the car easily. The battery pack is 10,000 watts so at full sun it would take about 33 hours for a full charge. You only get perhaps 6 hours of full sun on a good day, so you're talking 5 days for 1 complete charge. You would be getting maybe 4-5 miles of added range each day, with $0 electricity costs for those miles. I think either the efficiency of the vehicle would have to go way up (less watt/hours per mile), or the efficiency of the solar panels would have to increase before it would make sense financially.

on average i run about 300 miles per day in my sales calls, and i have not seen anyone boasting that kind of mileage out of electrics yet. filling up forty to forty five dollars per day in gas, is taking all of the fun out of my job.

300 Miles would be doable with current technology, but extremely expensive. It would require a massive LiFePO4 battery pack (like 75,000 watt hours) in a normal vehicle. Even at $1/watt (about the price of the very cheapest cells right now) it would be $75,000 for batteries alone. This technology can last for 10 years or more, so at $45/day it would take 4.5 years of gas savings to pay for a pack of that size.

A better alternative might be a hybrid. By recapturing the energy lost during breaking, having the engine shut off at stop lights and when traveling below 40 mph you could probably cut that fuel usage down by 1/3 to 1/2 depending on the driving conditions.

[OperationZ]

We get 30-53 miles on a charge on our 280Z EV, this link caught my attention (90% charge in 5 minutes?) http://www.autobloggreen.com/2007/12/11/toshibas-new-scib-battery-charges-in-5-minutes-releases-march

[Mr Camouflage]

I'm still not convinced that all that weight in front of the axle line is a good thing. The engine that was replaced sat mostly above and behind the axle line. I wonder what the weight distribution is now. How's it handle?

[jmead]

I'm still not convinced that all that weight in front of the axle line is a good thing. The engine that was replaced sat mostly above and behind the axle line. I wonder what the weight distribution is now. How's it handle?

I'm hoping the weight out front wont make a big difference. The total weight of the front is about the same, but shifted a few inches forward. I could have but the batteries on their sides and had a taller pack that was more over the axle, but it came down to a trade off between body roll and steering response. I decided to go with the lower center of gravity. I will push it soon and see how it performs, but there are a few things I need to attend to first.

OperationZ - That link certainly grabbed my attention too. I'm hopefull the technology comes to market soon, and that its not yet another unfulfilled revolutionary battery promise. It seems like there are several battery technologies right around the corner now poised to really take EVs up to the next level of performance/practicality, I figure at least one of them will become a reality.

[jmead]

We get 30-53 miles on a charge on our 280Z EV

What is your Wh/mi like? How many amps do you pull on level ground at, say, 50mph? It would be nice to have a baseline to compare against when I take it out for its first real workout in about a week.

[OperationZ]

Level ground 0% grade, 2nd gear @ 50 mph is about 80-90 amps, 40 mph is about 50 amps, remember my Z weighs 3220 with 1008 lbs. of batteries.

hope this helps

Joe

[jmead]

Level ground 0% grade, 2nd gear @ 50 mph is about 80-90 amps, 40 mph is about 50 amps, remember my Z weighs 3220 with 1008 lbs. of batteries.

hope this helps

Joe

These are battery amps, right? And what voltage are you running at?

[OperationZ]

Acutally motor amps drawing from the battery pack.

Our system is 144 volts, on a full charge our volt gauge reads around 156v.

[Walter Moore]

Generally are the (relatively) low voltages dictated by the available batteries?

Don't get me wrong, 150V is nothing to play around with casually, but in the industrial controls world, where I work, I have never seen any system installed that was capable of producing the power necessary to drive a car that operated at voltages that low.

Fifteen to twenty years ago we used to use 300V servos a lot, but anymore when you get above 22kw, most installations will switch to a brushless 600V system. The reason frankly is that when it comes to efficiency, current is the enemy.

One of the links listed above had a discussion of someone's car which used a 1000A controller. That is just insane. High current necessarily means big, heavy wires, and big heavy motors. Increasing the voltage by a couple of powers of two reduces the size and weight of the wires and motor, and directly reduces the parasitic loses of the system.

None of which helps I suppose if to get that extra voltage you have to go from a 1000 lb battery pack to a 4000 lb version.

Perhaps at some point in the future batteries could be made with a large number of smaller cells, like happened when cars went from 6V systems to 12V systems. Today's 12V batteries are in many cases actually smaller than the old 6V batteries used to be.

But as long as the small time experimenters are stuck with building battery packs out of 12V primary ignition batteries I guess the lower voltage system may be the only available compromise.

(I talked my self in a circle didn't I? :cheeky: )