A little about my project - Fuel Economy, Hypermiling, EcoModding News and Forum

j8reign · 05-22-2012, 04:18 AM

Ok, so here goes... I've grown to be disgusted by the high price of gas/ the horrible mileage of my current daily driver, a 98 chevy blazer (16 mpg)! And after several months of studying up, decided to do a 100% EV conversion! I looked around for a possible donor for quite some time, and finally was able to secure one in the form of a 96 dodge neon which had a blown engine. At this point, I've stripped it down... Removed everything from the engine compartment that wouldn't be used, dropped the exhaust, replaced all windshields/windows with lexan, removed seats and replaced with light weight racing buckets, removed hood fenders quarter panels trunk lid and bumpers and replaced all with fiberglass, replaced the wheels with lighter weight rims, and put disc brakes all the way around. At this point my neon is weighing in at just under 1400 lbs, so I'm off to a great start (I think)! Now I begin the hard (costly) part, I begin collecting the components to convert it to DC. When I'm finished, this car will be my daily to and from work car, and used for being out and about in town on my days off. I am planning on getting rid of the gas hog and purchasing a more economical car for long trips, but my Neon EV will see the most action. My round trip commute to and from work is 68 miles fairly flat for WV per day, and I'd like to have a little bit of extra in the batteries as a fail safe, is 80 miles per charge possible? I plan on using a warp9 motor, or at least something similar... Any suggestions as to batteries? I don't mind springing for LiFePo4 cells if necessary,and someone could point me in the direction of where to get them for the beat price. I was thinking maybe 96v at 200ah would suffice? As always any input/advice would be greatly appreciated!!!

meelis11 · 05-22-2012, 04:38 AM

Hi, welcome!
Can you make photo album of your project and give us a link?
Unfortunatelu I cannot give you advice because I dont have much experience with EV's. Is it possible to charge at work?

fb_bf · 05-23-2012, 03:09 PM

Well, your off to a very good start with that weight reduction effort. I have a converted MG Midget that you can see at www.electricmgmidget.com that has a 112 mile range and could be very similar to your build. I used 120 volts and 160AH batteries, so that is very close to your guess at what you'll need to get your required range. Be careful in picking the volts VS AH as that can change the way your car drives as far as acceleration. The total KWH will be more important to your range. I try to discuss my motor and battery trade offs at my site, so you will find that useful. I kept the transmision and clutch, which I highly recommend doing to get a good driving car. Please feel free to get in touch with me directly if you have questions. I'd be happy to help you in going through your design options.

j8reign · 05-23-2012, 05:41 PM

Quote:

Originally Posted by fb_bf

Well, your off to a very good start with that weight reduction effort. I used 120 volts and 160AH batteries, so that is very close to your guess at what you'll need to get your required range. Be careful in picking the volts VS AH as that can change the way your car drives as far as acceleration. The total KWH will be more important to your range. I try to discuss my motor and battery trade offs at my site, so you will find that useful. I kept the transmision and clutch, which I highly recommend doing to get a good driving car. Please feel free to get in touch with me directly if you have questions. I'd be happy to help you in going through your design options.

Thanks, much appreciated. At this point, I've located a very cheap source for LiFePo4 cells, or at least they seem fairly cheap, so my plan is to go with 48 cells, making a total of 153.6 V/160 AH/24.58 KWH... seems like a good setup? I've run the calculator @ EVsource and brought the projected weight of the vehicle up to 2200lbs. to allow for the weight of the battery pack, motor, and other components. The calculator projects that at 80% DOD, I'd get around 89.37 miles per charge. Does this seem correct to you? Thanks for the input!

Daox · 05-23-2012, 06:09 PM

I think you're pretty close to your 80 mile range.

Below is a range chart from the Leaf forums. At 60 mph the Leaf gets 82 miles of range. Your DIY setup while very similar to the Leaf likely isn't as efficient due to the DC vs AC drivetrain. I'm not sure what kind of efficiency hit you take here, but my guess would be around 5%. Of course you will gain some efficiency for having a lighter vehicle. I'm also not sure how much of a gain you'll see on the highway though. In town less weight will help a lot more though. If you keep the speed down a little you're golden.

fb_bf · 05-23-2012, 06:44 PM

Quote:

Originally Posted by j8reign

Thanks, much appreciated. At this point, I've located a very cheap source for LiFePo4 cells, or at least they seem fairly cheap, so my plan is to go with 48 cells, making a total of 153.6 V/160 AH/24.58 KWH... seems like a good setup? I've run the calculator @ EVsource and brought the projected weight of the vehicle up to 2200lbs. to allow for the weight of the battery pack, motor, and other components. The calculator projects that at 80% DOD, I'd get around 89.37 miles per charge. Does this seem correct to you? Thanks for the input!

Yes, that does sound very close. The weight will show up in around town driving. My route energy use calculator showed my daily commute energy use would change by 3% for every 100 lbs added or subtracted. That will vary with how much stops and starts you have. My pack seemed well balanced and that is why I got 112 miles out of it. I charge at 3.6 Volts tops, and stopped driving at 2.7 volts on my lowest cell while under 100 amp load. I would guess 144 volts and 160 to 180AH will also work very well. With a warp 9 impulse motor you'll be able to get about 92 ft-lbs torque at 550amps, and you can deliver that many amps out past 4000 RPM. The RPM limit is 5000, so you'd have full torque from 0 to very close to max RPM and stay very close to the 3C max current draw out of most LiFePo4 cells. What cells are you considering anyway?

j8reign · 05-23-2012, 07:34 PM

These are the cells that I am looking at, mostly for price... hopefully they will serve their purpose well.

160Ah, 3C, 3.2V Model: BP-HZPP-160 10.0 x 2.24 x 10.4in

Daox · 05-23-2012, 08:47 PM

I've never heard of that cell manufacturer. I have heard you can get calb cells for $1.2/ah which is the same price. They have comparable specifications and there are others using them so they're a bit more proven.

tortoise · 05-23-2012, 08:57 PM

Quote:

Originally Posted by j8reign

. . . replaced all windshields/windows with lexan

W. Virginia safety inspection requires AS1 or AS10 safety glass for windshield.

mechman600 · 05-23-2012, 08:58 PM

Sounds like a great project!
My advice is that you go as high with voltage as possible within your budget. The higher the voltage, the less efficiency is lost to heat in your cables and whatnot. You can go quite high before a Warp9 turns into molten lava - something like 192V is still within reason. Plus, when you want to have fun going fast, high voltage will put a giant smile on your face. Controllers do get quite pricey above 144V but many people say it is worth the investment. Keep searching the EV trading post for parts. [EV Tradin' post] - Electric Vehicle Classifieds
You can register to get alerts emailed to you when something you are looking for goes up for sale.
Best of luck!