A Little Summer Maintenance

The Electric Booger has been parked since the insurance ran out at the beginning of the month. In Summer I ride my motorcycle exclusively, so no sense wasting money on car insurance when I don't need it.

Today I pumped up the tires and drove it around my townhouse complex just to make sure things are all still good. They are. Funny thing about an electric car. Even after sitting for three weeks just switch in on and drive it. No fuss. It is as if I drove it to work yesterday.

I am charging the pack, letting it float charge all day. It uses about 50 watts to keep the batteries happily sitting at 13.5V. It's something I do about once a month when the car sits.

In a few weeks I will put a permit on the car when my parents come and visit en-route home to Manitoba on their Alaska trip. They have never seen the car before in EV form, so I do not want to waste the opportunity to show it off!

Since it does not look like anybody wants to purchase the Booger, it looks like it is mine forever. So I think I will install my home made Arduino based BMS & fuel gauge over Summer. At least it will keep me interested in the car for the time being. And maybe a cool new paint job? We will have to see.

Busted Spring

More suspension woes.

Come to think of it, the Electric Booger has been leaning to the right for as long as I can remember. I just never gave much thought to it. When it recently snowed and the roads were slippery, I found the car absolutely treacherous to drive, like it couldn't decide which way the steering wheel needed to be pointed in order to go straight, depending on which tires were on ice. Finally, when the front right corner of car started to make awful noises going over bumps, I knew something had to be done.

I jacked up the front right corner,and found terrible badness: the spring was broken.

After scouring wreckers and parts stores and coming up short, at least at a price I deemed acceptable, I finally found a new spring in Quebec on eBay. And three days later it was here. It literally took 20 minutes to replace.

FOR SALE

The Electric Booger is up for sale. Here is the official ad, copied from Craigslist:

"ELECTRIC BOOGER 1992 Mazda MX-3 EV Conversion - $4200 (Cloverdale/Clayton)

It's time to put my electric car on Craigslist.

The Electric Booger started life as a 1992 Mazda MX-3 Precidia. I bought it for a Winter beater, and after commuting with it for one winter I decided to convert it into an electric car.

Firstly, this isn't a Tesla. It wasn't mean to be. It's a low budget EV conversion done right. If you know little about cars or nothing about electricity, this car is not for you. It requires periodic minor tinkering to make sure everything is a-ok. But so far after over 3000 km gasoline free, it has never left me stranded. I get in, turn the key on and drive. Get there, plug it in and walk away.

Secondly, this car is not meant to fly down the freeway from Surrey to Vancouver and back every day. That's what $30K store bought EVs are for. This is an in-town/back road, short range commuter, and it excels at it.

The full build log can be seen here: http://electric-booger.blogspot.ca
And here: http://ecomodder.com/forum/showthread.php/project-electric-booger-budget-ev-conversion-92-mazda-22478.html
The EV Album entry can be found here: http://evalbum.com/4473

SPECIFICATIONS:

Motor: 8" Baker Series Wound Forklift Motor
Controller: Alltrax 7245 - 72 Volts/450 Amps max (approx 30 horsepower)
Batteries: 12 X 12 Volt 92aH AGM, Branded "TRP" (a rebadged MK/Deka)
System Voltage: 72 Volts
Instrumentation: System voltmeter, switchable volt meter for monitoring individual batteries
Transmission: Original 5-speed, no clutch
Charging: 6 X 12 Volt/10 Amp eCity Automatic Chargers, 120 VAC (regular wall outlet)
Charge Time: <4 Hours after a 13.1 km commute
Heater: 700 Watt Electric, Uses regular blower fan/ducts. Not hot, but keeps the windshield fog free
Top Speed: 90 km/h, but it is much happier if you keep it below 80 km/h
Range: 30-40 km, although this is a guess. 20 km in the cold of winter is no problem

I really think it will be a hard sell. I don't think anybody in their right mind wants a beater MX-3 EV. (What does that say about me? :O) I am already dreaming up a contingency plan if I cannot get rid of it.

First off, I will ditch the MX-3. It's in poor condition (dents and scratches), getting old (285,000 km/177,000 miles), and a bit porky (2332 lbs original curb weight). So if nobody wants it before my insurance runs out in May, I am stripping the EV goodies out of it and the scrap guy will haul the glider away.

Possible replacements:
Festiva: 1797 lbs
Swift/Firefly/Metro: 1895 lbs
Tercel: 2090 lbs

My first choice is a Ford Festiva. Maybe the coolest nerdy eco car ever.

"Here, Cheyenne [my 4-1/2 year old daughter], draw me a car. Wow, perfect, you just drew a perfect looking Festiva."
Curb weight of 1797 lbs. That's 535 lbs lighter. Also, I will likely buy a lithium battery pack, which will save an additional 574 lbs and actually fit in the car.

With over 1100 lbs lost, I think I will be happy with my current motor and controller. My Alltrax 7245 controller is meant for 72V nominal but it has a max voltage of 90V, so with lithium I will be able to "cheat" a bit by going with an 80V system voltage (25 cells), where 90V will be 3.6VPC.

Busted Rear Strut Mount

The Electric Booger has been running great. Now that the weather turned cold...well...for around here, around zero celius (32F) in the mornings, I definitely notice a lack of performance showing up as voltage sag (down 1.5 volts during normal acceleration). But my range hasn't been affected much, or so it seems. Not that I ever exploit the full range of the car anyway.

A few weeks ago I started to get a squeaking noise coming from the right rear strut area. At first I thought it was a problem with the ex-rear seat, battery rack, hatch or even the body cracking because of the extra weight. Then the noise progressed to a clicking noise. Then on Thursday, as I rounded a corner and hit a bump, there was a large BANG, followed by a constant RATTLE CLUCK KNOCKIDY KNOCK KNOCK. I stopped for a quick visual and finding nothing obvious, I kept driving.

Up on the jack with some interior panels removed, I was startled to find that the right rear strut mount had rusted right through and broke. Here's a video:

It turns out that a guy at work used to have a Mazda Protege and had an extra brand new strut mount, which also broke on him and also fits MX-3s. I gave him a few bucks for it, borrowed his spring compressor and made short work of making the repair.

Check out the rustiness:

And the knackered strut mount:

Here is the strut with the new strut mount installed:

It was not looking forward to spending money on new struts, but as it turns out, this strut is an aftermarket KYB strut, so they have been replaced before. It still felt quite good when I worked it up and down. Excellent....now I don't feel bad for being cheap by only replacing the mount and not the strut as well. But I should probably be proactive and get another strut mount for the left side and replace it as well, hey?

What Gear To Start Off With

First or second, that is the question. First is quicker off the line but the shift to second takes some time. So which way is quicker? Armed with curiosity, I took a video with my (cough...hands free...cough) smartphone to compare the two ways of starting off from a stop:

So it is a tie. 0-50 km/h takes 13.5 seconds with both methods. The quicker acceleration of first gear is exactly offset by the time it takes to shift to second gear. And since starting off in second is easier, that is what I will do from now on.

Tachometer Virtues

Having a functional tachometer in an electric car is amazing. I cannot believe I didn't do this before. It makes driving 100% more enjoyable.

1. Downshifting without a clutch is now slicker than goose poop because you precisely know your "blip RPM". Try blipping the throttle on a motor that you cannot hear. That was me before. I suppose that for those who keep the clutch in their EV conversions this is not an issue.

2. I now have figured out my power curve and shift points. I used to guess before based on vehicle speed. Now I do not have to. Peak power is at 3400 RPM. I can tell because of the sudden slight lurch of power and drop in battery voltage (a few tenths of a volt) when the Alltrax reaches peak output voltage and goes into bypass (which is another reason I love my Alltrax controller, because it has an internal bypass making it nearly 100% efficient at peak output). It is pretty much out of steam by 4000 RPM. By 4500 RPM it is really not accelerating anymore. I can now shift by RPM instead of by vehicle speed.

As you can tell, the Electric Booger is running better than ever and I am very happy with it. Thanks again to my Ecomodder.com friend Darin (MetroMPG) for giving me this series wound motor. Well, "giving" is a strong word because the deal was that I now owe him a case of home made beer. So in my garage is 6 gallons of a very dark, highly hopped ale.

Here is my helper helping me mash the grain, making delicious, sweet, fermentable wort:

Fuel Efficiency Log

Power consumption is calculated into MPG equivalent (MPGe), assuming one gallon of gasoline contains 33.6 kWh of energy.

My electricity costs $0.112/kWh (BC Hydro step 2 rate, including tax), which calculates to $3.76/US gallon ($0.99/L) equivalent.

This graph will keep updating as I continue to fill out my fuel log on ecomodder.com.