Electric car conversion: Project ForkenSwift

[capn_r]

Excellent, thanks for the fast response and information. I’m going to be lucky on the motor end as I will have a standard keyed male shaft. I like the idea of using the lovejoy for ease of assembly / disassembly and the little bit of cushion and alignment tolerance of the coupler. Thanks again and keep up the good work!

[MetroMPG]

No problem!

Got an EV Album entry or web page we can look at to see what you're up to?

Note that Dr Larry cautioned against a soft (rubber?) spider between the two lovejoy halves. He's running 72v with a higher current controller, and I believe he torqued a spider to death.

I'm not sure what material ours is, but it seems harder than rubber. Some kind of urethane, I think.

[capn_r]

I don’t have a webpage (I’m technologically challenged) but what I’m starting to do is converting a Chevrolet Sprint and just starting to gather components for the project. I was just surfing the lovejoy site and I think I will just go into a supplier after I have a little better idea of what I want. They (lovejoy) listed several spider components and at this time I think the urethane option is the best for me. They listed another one that could handle more torque (hytrel) but they didn’t recommend that compound for a cycling application. I will be lurking and I’m sure I will have plenty of questions (hopefully I won’t get too annoying) I’m not going to be able to compete with how much money you didn’t spend but it will be a budget process. Having your experiences to learn from is a real bonus. I often wonder how we functioned prior to the internet. Thanks again!

[MetroMPG]

Woohoo! First complete charge with the "new" Delta-Q 48v charger only took 5.5 hours - and that was for 80-90% DOD (guessing). I know, I know - I'm a bad boy to draw it down that low.

To compare, the 24v 10A Vulcan took approximately 16 hrs to replace the same amount of energy.

Too early to definitively say whether it's more efficient than the old charger, but the energy usage of this drive/charge cycle put it at 4th best out of 13 recorded cycles:



http://ecomodder.com/forum/em-fuel-log.php?vehicleid=12

This is the first time since the end of Feb that I've been able to record a cycle because the old Vulcan 24/10 hasn't shut off automatically, making it impossible to determine accurate energy usage for distance travelled (sort of like the gas pump not clicking off and gas pumping out on the pavement).

[bennelson]

Keep an eye on the new charger!

You are checking it with a Killawatt or something similar, right?

I noticed a HUGE difference in energy use between big old standard car battery chargers and the electronic 36V charger I am using on the motorcycle right now.

Part of energy use is how much is wasted converting it. New fancy chargers convert it so much better!

I am a little afraid of using my 36V Forkencharger (which isn't even hooked up because it is currently rigged for 440 Volts!) because I am sure it must be pretty inefficient.

Might work well in the winter when it's OK to double as a garage heater!

Have fun charging!

[MetroMPG]

Yeah, using a kill-a-watt.

The old 24v one is much like an old car battery charger. Gets hot & buzzy.

The new-to-me 48v unit is completely sealed, quiet. So I suspect it's much more efficient - I've asked the EE who sent it to me if he has any info about that.

I'm going to take the car out for a rare "pointless" run tomorrow to mimic another one I did in Dec (similar temps). Data collection!

[jwxr7]

Hey Darin, with some of your testing on your EV, have you come up with any estimates for powertrain loss in a geo metro. For example, Did you compare wattage for spinning the motor unhooked from the trans at a given speed to running it with the drivetrain spinning and the car on jack stands at the same motor speed? So we could see about how many watts are lost on the way to the wheels.


Also, forgive me if you have given this info before, but do you have any data estimates on watts vs. ave cruise speed for you EV.

I figure it is easier to measure these things with a car running on electricity than with a gasoline powered car.

[MetroMPG]

I haven't spun the motor @ 48v with the ammeter attached, so I'm not sure. But we're planning to tear down the car this spring to clean it up/paint/finish things a bit nicer. So I'd consider doing it then.

I don't have any energy use @ various speeds data yet either. Mostly because it's hard to keep the speed exactly constant and the ammeter from moving around to get a reliable reading.

But today I was thinking that I'd like to attempt a test to determine which gears/shifting technique I should be using for best efficiency. I've seen conflicting advice on that front.

[bennelson]

Still waiting on those number from the new charger!

Come on, isn't it finished charging yet?

I calculated my 5 mile round trip ride on the cycle last night as 263 mpg based on cost and 321 mpg based on BTUs of energy used.

[MetroMPG]

Yeah, the last 2 charge cycles in my fuel log are with the new charger. Look for yourself.

IT'S AWESOME. Not because it's noticeably more efficient (the charge cycle efficiency is in line with what I've seen from the previous charger) but because it's so much quicker. 5.5 hrs and 5.25 hours to completely recharge. VS 12-16 hours on the old charger.