Electric car conversion: Project ForkenSwift

[MetroMPG]

TomEV - thank you for the information. I am running a pair of SLA alarm batteries currently. (Which is why I can kill them with lights & blower in 20 minutes on a cold night). So, yes, I need to reduce the output voltage or suffer the consequences!

SW - it's apparently rated 0 to 6.66A continuous. And a diode was recommended if I am to leave it connected to the 12v battery (see Lee Hart's advice, link below), as well as using the trim features to further reduce output voltage.

Ben - thanks for posting that info! (And congrats on beating me on a parts purchase )

I also got a couple of detailed replies to this query which I also posted on the EVDL. If anyone wants to read them...

http://www.evdl.org/archive/index.ht...54%7Ca15514216

It's not quite as simple as I was hoping. (IE not just hooking up 4 wires and a switch.) Apparently for longevity of the device, I've got to also connect in a "transient voltage suppressor", a Filter capacitor, fuses and misc other stuff. See Lee Hart's reply in particular, if you're interested.

Lee is one of the Yodas of the EVDL, so I will be following that advice so as not to let $20 worth of smoke out of the little box.

[MetroMPG]

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

Worst ever "fill up" since I started tracking it - 62.5 MPG(US) equivalent. Combination of very cold temps & recharging it before it was too drained.

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In better news, on the advice of one of the EVDL Yodas, I bought another DC-DC converter off eBay, and it arrived yesterday. $26.50

It's the exact same VICOR model we already had, but it comes mounted on a circuit board with the needed bits and pieces to ensure we don't burn it out prematurely by hooking it up "raw" between the 48v pack & the 12v accessory battery.

I could have assembled the circuit components to do the same job as this little PCB, but this was just easier.

So... I may have the "naked" VICOR 48-12v DC DC for sale, if anyone's interested...

[MetroMPG]

Wow. What a difference the temperature makes. It popped up to 13 degrees C here today. Hasn't been that warm for maybe 5 months.

The difference is noticeable... like a different car! I actually felt something akin to acceleration when I shifted into 4th gear trying to get up to 50 km/h - I don't remember feeling that ... ever, truth be told.

And not driving gently at all, I'm up to 13 km so far on this charge. In the colder weather the car is on its knees around 10 km, and pretty much crawling on its belly at 13.

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Stopped by the forklift company this afternoon to see if they guys were in who helped this project along. Both Ralph (the tech who "sold" it to us and got us the EV1 controller schematics) and Kevin (the parts guy who got us our test pack of floodies from the floor sweepers they service) were there, along with another tech.

Had a good show 'n' tell in the warm spring like weather. Everybody had a good chuckle and lots of interesting questions.

Ralph liked our golf cart controller. He popped back into the shop and came out with a 48v 550A Curtis controller. 2x the power of our unit. Drool. Said he'd keep his eyes peeled in case something shows up in their forklift bone yard.

[MetroMPG]

Just got in: 18 km on this charge, and didn't even have to crawl up that last little grade in 1st gear, feathering the go pedal to keep from murdering the floodies.

Got to love the warm temps!

I have a feeling the car is going to pull off some decent efficiency numbers this spring/summer. I figure tomorrow morning's calc's should show that today's usage was well above the average.

[Peakster]

Originally Posted by MetroMPG

Got to love the warm temps!

+13*C? I wish I could just taste that!

I'm excited to see how well your EV performs in summer. My prediction is that you'll get 30 kilometres on one charge at least once this year

[AndrewJ]

That makes me wonder what the efficiency return (if any) would be on battery warmers and insulation?

Clearly this wouldn't be an option if you're leaving the car in a parking lot for several hours...but still....several hundred lbs. of lead is a pretty substantial thermal mass.

[MetroMPG]

Makes me wonder the same thing. At the very least, next winter we should insulate the batteries with foam board. The batteries heat up when charging & discharging, and that'll help hold some of it in.

Of course I knew all about this before winter set in. But I'm one of these people who can read about it and get all kinds of advice, none of which I'll take until after I experience it myself. Doh!

The guy who donated the batteries to us drives his converted Ranger EV pickup year round in Ottawa, and he has insulated battery boxes with thermostatically controlled heating pads.

The problem - you saw it too - is that if you're not using the vehicle regularly, it's harder to do this (and have it be worthwhile from an energy use angle). And the car doesn't get used every day, normally.

Still: fun, fun. The rolling science experiment rolls on.

[MetroMPG]

Got some questions...

I was noticing your black fly is getting almost the same MPG vs the ForkenSwift..

I also realized you hardly put any miles on the Forkenswift when you do use it..

How far can you go on a single charge?
just curious..

Yeah, both cars are around 75 mpg (US) equivalent now. The cold is killing the range and efficiency of the batteries. I have a feeling I'll be able to double the ForkenSwift's MPGe in the summer time.

Range... In sub-freezing weather, 10 km / 6 mi. is about the max usable range. It's double that in the summer.

Remember these are used batteries that were removed from another EV because the owner deemed them to be toast. A new pack would likely at least double the range again.

[Chris D.]

did you mate this upto the stock transmission or is it DD?

[MetroMPG]

Motor is mated directly to the stock 5-speed. No clutch.