Massive EV Grin On Test Drive #2

It turns out all I had to do is reverse the polarity of my field power to make the car go the right way. And I didn't blow up my field spike suppression diode. And I believe my field power interrupt relay welded itself shut because it was really cheap.

Test drive #2 was merely around our townhouse complex. It wasn't far (a few hundred feet) and it wasn't fast (20 km/h), but it sure was exhilarating! And eerily quiet.

I got around to buying some insurance for the eBooger. It turns out, all I had to do is ask the nice insurance lady to switch my fuel type to "electric" to change it. I don't know if it actually means anything, but it sure looks cool on the registration!

First Test Drive Fail

Yes, there was a first test drive. But first, an update.

Battery cables + traction wiring - DONE
Rear battery pack venting pipes - DONE
TPS + control system wiring - DONE
Vacuum pump + vacuum pump wiring - DONE
Motor field control wiring - ALMOST DONE.

And this leads us to this morning's test drive attempt. Key switch on, all systems go. Put it into reverse to back off the ramps. Car lurches forward. Huh? Scratch head. Put it into first and the car backs off the ramps. Put it into reverse and drive forward back up onto the ramps.

Hmmm... So it has one forward gear and five reverse gears. I messed up somewhere. And my field interrupt relay welded itself closed, so power is always going to the field windings even with the key off and foot off the go pedal (until I remove the relay).

I have a good idea of what I did backwards but I will have to update later.

Here's a schematic of the field wiring. A pretty high tech drawing, I know.

Heater

The other day I went out and bought the $10 blow dryer from Canadian Tire. I dissected it to get the heating coils out of it. Built into the coils is a bimetallic temp control switch and a thermal fuse for safety.

I was blown away (no pun intended) by how cheaply made this blow dryer is. The frame that the heating coils wrap around is two pieces of cardboard with a thin reflective coating so it doesn't immediately catch on fire!

With a healthy dose of duct tape and a few screws I installed this unit into the pipe that connects the blower fan to the the heater box:

All of the blower fan air is forced through the ex-blow dryer. After installing this pipe back into the car, I decided to run a resilience test. I turned on the car's heater fan and plugged the hair dryer heating coils to the wall outlet for about 10 minutes. I am happy to say that the heater instantly blew warm air. There was no melting, burning, funny smells or fire. I pulled the pipe back out to inspect the duct tape and it looked good.

Instead of 120VAC, the heating coils will be powered by 72VDC in the car. That doesn't sound like a lot (40% less voltage) but I did notice that no matter what speed I ran the heater fan during the test, the air seemed to stay the same temperature, indicating that the bimetallic temperature control was hard at work doing its job. What this tells me is that 120VAC is way more than enough to maintain the target air temperature at any fan speed, so 72VDC will most likely be enough [at least] in the lower fan settings.

In other news, I spent lots of time making battery cables yesterday. I had plenty of 4/0 truck battery cable to do the job. Armed with a borrowed terminal crimper and 36 copper 3/8" battery terminals, I got it done. Today I made a bracket to mount the contactor (the main disconnect relay that all traction power goes through) and I mounted the controller. Once the control board (literally board. It's a piece of Ikea shelf) is more complete I will post pictures, mostly just to confuse everyone, including myself.

The Running Gag In ALL EV Conversions

You can put a charging cord almost anywhere in an EV conversion: under the hood, in the trunk, etc. However, you will find that in each and every conversion, the charging plug is ALWAYS located where the gas cap used to go. It's the running gag that simply states, "nothing goes into this tank except electricity."

I just finished making mine:

All The Batteries Are In

Yes, I did in fact break a sweat hand bombing 798 lbs of lead batteries into this thing!

Here is the rear pack ready to be wired up:

And de-apholstering the rear seat has made a brilliant area to mount the rear chargers.

Hopefully tonight I will be able to sort through all the used truck battery cables I have laying in the corner of my garage.

Wheels Spinning By The Magic Of Electricity

I have sort of been putting off reinstalling the axles, so today I finally got to it. And this, ladies and gentlemen, means that I was finally able to test out the entire drivetrain to make sure when I give it power, the wheels will actually spin.

Here it is:

Battery Racks & Heater Plans

I have been very busy working on the Electric Booger. A couple of visits to Metal Supermarket and a welder borrowed from my buddy Trevor allowed me to complete the battery racks.

Here is the front rack:

With batteries in place:

Yesterday I completed the rear battery racks:

That's right, no more back seat. My choices were to keep the useful trunk and use the useless back seat for batteries or keep the useless back seat and use the useful truck for batteries. It was an easy decision.

Now on to the heater. As everyone knows, with a lack of ICE, there will be no hot engine coolant to keep me warm on cold winter mornings. The usual EV conversion solution is to remove the heater core and install the ceramic element out of a small 110V heater. However, after doing some research on MX-3 heater core removal, I have decided against this. You basically have to disassemble the entire dashboard to get the heater core out, and right now I do not have patience for that.

The other day I was giving the heater system a good hard look. It turns out that the heater fan box is at the right side of the car and connects to the heater box with a plastic pipe that takes about 10 seconds to remove:

So here's the new plan: buy a cheap hair blowdryer to stuff inside this pipe so all the heater fan air is forced through it. I will power the heating elements with my battery pack through a decently sized contactor. Sounds like a plan to me. Hopefully this plastic pipe won't melt too quickly!