Electric car conversion: Project ForkenSwift

[Silveredwings]

Originally Posted by MetroMPG

Well, the 400A unit has a user-settable acceleration ramp (via a pot), and a couple of other adjustments. Haven't played with them yet.

I always found the 225A acceleration ramp to be sluggish - it definitely wouldn't give you 225A immediately from a standstill (though you could get it under way). And it would bog down in thick snow at low speeds (ie come to a stop, with no amps showing on the meter).

I see. 225A to your motor and car weight it is sluggish. Maybe on a bike with a smaller motor, it would be blistering or even hard to control.

Still, it seems like putting a slower 'acceleration ramp' on the 225A is a little like taking a guitar amp and graduating the volume control so "it goes to 11."

[MPaulHolmes]

I'm sure you know this already, but check out ebay! 100 72v 400 amp curtis controllers!!! Cheap starting bids!

[MetroMPG]

Great find. Thanks for posting that. I need a sixth controller.

[bennelson]

Yep, 5 more ForkenSwifts and you can carry them around in a six-pack ring!



I may need to keep an eye on these for my Metro build.

[PeteM]

Hi,

Nice work on the Forkenswift, I've spent a few hours over the last few days getting educated on your build.

I am currently looking into building my own EV and I am stuck on the process of getting the car certified for the road. Can you point me to any documentation or Ontario Gov web sites with details on what needs to be done?

I gather from your build that the process included getting the donor car certified first and then converting, so I would probably do the same, it's the post convert process that I am interested in. Can any Motor Vehicle Inspection station do the work, or did you need to find a "special" place?

Thanks,


--Pete

[MetroMPG]

Hi Pete-

There aren't any documented rules you need to follow to have an EV conversion certified in Ontario. We thought having it certified before doing the conversion would simply save some hassle having to do a lot of explaining, so that's what we did. But it turned out the insurance company required an additional inspection anyway (since the original inspection had expired after 30 days or whatever it is, not because it was an EV).

That said, I'd take the vehicle to a mechanic you have a relationship with already, since they have a lot of lattitude to interpret the regulations and you want someone who will help you to make sure the car is safe, not simply throw up road blocks. I used my regular mechanic that I've been going to for several years.

You might want to ask on the Durham EV Association Google group for specific recommendations in the Toronto area. Their website: http://www.durhamelectricvehicles.com/

Their discussion group: http://groups.google.com/group/Durha...iation?lnk=srg

[RarestAce]

i just finished reading your whole conversation and i must say what an amazing job you guys have done. I really cant wait to see what your car can do with the 400 amp controller

[MetroMPG]

Hi RarestAce - thanks for the compliment. The 400A controller is great. It's nice to have the extra power when needed, which is rare, but better than willing the car forward when more accel is needed. FYI, accel to 50 km/h is 21 seconds vs. about 36 seconds with the 225A unit.

---

Update!

Ivan and I will be pulling the car apart probably next week to clean it up - paint the motor compartment, components, and generally tidy up the installation. But before that we wanted to get a better picture of the health of this set of batteries.

So... yesterday we installed the LED pack monitor I talked about back here.



It's awesomeness can't be underestimated. Up to now, we've only been monitoring a single battery in the pack - the one we thought was the weakest. Rule of thumb: avoid drawing the weakest batt below 5.25v under load.

Well, oops. Within 15 feet of driving, the dancing equalizer-like LEDs showed us several things, not the least of which was we were NOT monitoring the weakest battery all that time. We had a true dud in the pack that fell on its face under the lightest load.

I'm going to post pics, and maybe make a short YouTube vid about this handy device. It's very cool to watch, and immensely useful. Every EV should have one (esp. if you've got an older, less balanced pack).

[RarestAce]

thats great when its all done it sounds like it's be one sweet little car to drive around. hopefully you'll be able to get yourself a nice set of batts one day but its just a great project thumbs up man

[MetroMPG]

If we keep the car long enough to completely wear out the 2 sets of old batteries we have, I'm sure we'll feel like a new pack will be worth the investment.

Besides: now we're properly equipped so that the investment would be protected: the combination of the proper 3 stage smart charger and now a proper means of monitoring the pack means it wouldn't be abused by our (old) dumb charger or damaged out of ignorance from over discharging the weakest battery(ies) while driving.

I'm definitely going to make up a short YouTube vid showing the LED pack monitor. It's too cool.

[bennelson]

Sounds like I will need one of those LED pack monitors once I get my Metro going.

[MetroMPG]

Definitely. There are several styles available, some quite easy to make yourself, and the guy who made the one I'm using posted a schematic & a parts list.

I just recharged the car this morning (Ivan's had it for the last week or so): best ever efficiency: 126.9 mpg-e. Or 264 Wh/mile. That's really good! Mostly it's the warm weather, and the fact that the car was fresh off the charger before driving & recharged immediately after.

I'll have more runs than normal in the next few days as I use the new batt monitor to swap batteries around and make up the best possible pack from the floodies sitting around here.

[MetroMPG]

New YouTube flick:

Instrumentation, ftw!

[MetroMPG]

Since "installing" the LED gauge, I've swapped out four batteries for "spares" that were sitting around. (They'd been more or less kept topped up once every month or so.)

The LED monitor is fantastic! By being able to identify - and then replace - the worst battery from the pack, I've managed to improve the range of the car significantly. The furthest I'd gone on this pack was 16.7 km, with an average closer to 12 km. I just rolled in with 19.4 km on the odo (and it wasn't on its knees, either). And this is the "B pack"!

I've done quite a bit of driving in the past 2 days sorting out batteries.

Of course, if I'd ever built a decent load tester, I could have figured out which batteries were strong/weak sooner than this.

[MetroMPG]

Ivan had the car for most of this week, but I went and got it this afternoon. Made good use of it for its last trip in probably a week or two while we pull it apart and pretty it up for the EV Expo in Ottawa at the end of the month.

- took a murdered battery up to the recycling place (10 bucks! Wish I'd held on to all the other ones I turned in earlier :P)
- brought half a dozen bags of yard trimmings to the city compost yard
- picked up the new front wheel bearing

I drove the car on two of the city's busiest roads. When traffic is heavy, the car actually does OK because people can't go fast anyway. One guy went around me "aggressively", but I rolled up beside him 3 times in a row at red lights. What a doofus!

So the next update will be pics of the tidying up of the motor compartment. (Can't say engine compartment any more.)

[MPaulHolmes]

Yo Darin! 'Sup? I have a question: Could you tell me these dimensions in my ugly picture of the little spline that was removed from your clutch plate (clutch disk?) and welded into your lovejoy connector?

-Paul

[MetroMPG]

If you're not in a hurry, yes. We're going to pull the motor compartment apart tomorrow evening, and one of the goals is to inspect the lovejoy/splined stub shaft for play and wear. I'll measure it up and get back to you.

[MPaulHolmes]

Originally Posted by MetroMPG

If you're not in a hurry, yes. We're going to pull the motor compartment apart tomorrow evening, and one of the goals is to inspect the lovejoy/splined stub shaft for play and wear. I'll measure it up and get back to you.

I'm in no hurry. Also, By the gray part I meant the part that is not visible on the clutch disk. The black part is the part that is visible before the destruction of the clutch disk.

[mattW]

Hey Darin,
Do you have a schematic for those battery monitors? Some DIYers are intersted.

[MetroMPG]

Hi Matt - it's on EV Convert: http://www.evconvert.com/article/led...onitor#c002474