Sunday, October 11, 2009

Video: Driving Clips

My wife recorded a short video of the car driving away - and yes I can touch the ground without my butt leaving the seat!

And coming back!

(Don't worry, the dog landed fine. He's only 2 feet off the ground when standing on the car after all.)

Main Cables Pt. 2

The hole for the main cabling in the trunk was pretty tight and had very sharp edges around it (a Dremel cut it after all!). I was afraid that over time the sides of the hole could cut into the main cables and then hilarity (er, major disaster!) would ensue.

I disconnected the main cables and moved the battery charger out of the way to widen the hole a bit more. I then found a 1" diameter flexible hose in my storage room that was from when the car was still gas. I cut a piece the same distance as the circumference as my hole and then a second cut lengthwise so it would fold open. I wish I had pictures, but I was just playing around with it to see if it would work!

I then stuffed the rubber hose inside the hole...

And pulled the main battery cables through...

It's actually a very nice tight (but not too tight) fit! The rubber is very thick so I feel much more comfortable with the cables being protected from the sharp edge now.

Friday, October 9, 2009

It's Legal!

I called up the Arizona Department of Motor Vehicles and asked about getting the car registered. I'm actually a Texas resident and am moving back to the Great Republic of Texas in December. Rather than having it registered in Arizona, I was able to get a 90 day nonresident permit, perfect! Only $15, no emissions inspections/waivers, and no hassle. When I get back to Texas I'll have to mess with getting it inspected / re-registered, but that's not for a couple months. :-)

Immediately after registration I called up USAA - within minutes I had an e-mail with proof of insurance! They really had no problems at all insuring a converted car.

I still have lots of clean up items to take care of before Bumblebee is a daily driver, but he should have his first out of the neighborhood drive this weekend!

Sunday, October 4, 2009


This past weekend I installed the charger permanently into the car. The floor of my trunk isn't very level, so I used some extensions for the back bolts of the charger to get it mounted.

The charger requires a signal from a BMS to operate, but I don't have a BMS installed yet. As a workaround until then, I installed a 9V battery with a switch.

I'm still working on the controller cutting power when I throttle up. Once that's worked out though, I'll venture into the process of getting the car legal!

Tuesday, September 29, 2009

Video: First Drive!

The first test drive!

The drive went pretty well. Throttle control was very smooth, but acceleration from a stop was very poor (sub 20 amps). I used 1st gear only, in 2nd gear the car barely moved. As speed increased, available amperage also increased (up to 150 amps at 15 mph), which gave me significantly better acceleration. I've sent an e-mail to the motor controller manufacturer for help.

Video: Wheels Off Test

Video of car running full battery pack and controller, wheels off the ground.

(Nearly) Final Wiring

My pictures from yesterday weren't very clear, so here are some new ones! The car is basically completely wired (excluding the charger).

Under the hood...

In the trunk...

Behind the rear wheel...

Under the car...

Monday, September 28, 2009

Main Cables Pt. 1

The final parts for my car arrived this past weekend. I took my raw cables and lugs to a local welding shop to have them crimped. Just for reference, here's the latest wiring diagram...

And here's the newly crimped cables!

I widened an existing hole in my trunk with a Dremel to fit the cables. I will put something around the cables soon so they won't be cut by the sharp edges as I drive.

Cables underneath the car...

I'm using small bolt-on cable mounts to attach the cables to the car. Unfortunately I forgot to take a picture of one of them! Maybe in a later post. :-) I also pulled off one of the rear wheels to add additional mounts for the cable.

Two main cables running to the front of the car. The red cable is attached to the fuse, which is the "most positive". The black cable runs between the batteries in the front and the back to tie them all in series. You can see a short black cable at the top of the picture that is the "most negative".

I had my wife standing by with a wooden baseball bat to pry me off just in case I did something stupid while wiring. She looked a bit too excited to "help" me!

Everything wired, 98.3V!

I was hoping to get the car running over the weekend but had some issues with my charger. (Nothing wrong with the charger, just a combination of poor documentation and user error.) It's charging now though so stay tuned for a test drive!

Sunday, September 6, 2009

Battery Box Pt. 2

Time to get the batteries in the car!

Battery boxes primed...


The mount for the spare tire was in the way, so I went ahead and cut it out.

The front battery box in place. Looks good!

I don't want the batteries resting on mounting bolts, so I cut pieces of wood to give the batteries a uniform base to rest on.

Spacers installed up front...

Batteries in place!

The trunk!

The nose of the car isn't sticking up anymore! I gave a few pushes on the suspension, and it seems to be handling the load fine. Weight should be about stock though so I'm not expecting any problems.

What's left: cables, charger

Sunday, August 30, 2009

Battery Box Pt. 1

I found a local metal supplier and drove by to pick up a couple steel plates...

And then while I was there I asked if they could cut them...

And then I asked if they had a couple angle strips...

And then I asked them advice on my design...

And then they basically built the entire thing for me while I waited!


The smaller battery box for the trunk...

Sure looks good in the car!

I 'would' have pictures of me drilling the mounting holes for the battery box, but alas my drill was out of power (see my battle with the charger on post July 2, 2009).

On a side note, the larger box was a bit too tight so I had to dremel down the corners to get the batteries to fit. When the battery finally squeezed (rather quickly) into place it did so with my toe in the way. Luckily it only ripped off a chunk of skin instead of a chunk of toe. I'll refrain from posting any bloody pictures though. :-)

Monday, August 10, 2009

Batteries Arrived!

It's Christmas in August! My batteries have arrived!

My plan to fit them all under the hood isn't going to work. If I had just 1 more inch I think all 30 cells would fit, but as you can see in the picture, just 20 cells fill up the space quite well. I'll throw the remaining 10 in the trunk.

On the bright side the split pack will help distribute the weight, down side is I have to run cables down the length of the car.

Picture of the car without batteries...

With batteries, the dog, and me in the car (Timber left his toy by the camera)...

I measured the sizes of my mounting plates for the batteries and the cable lengths. I'll order those soon so I can get these batteries mounted permanently!

Sunday, August 9, 2009

Heat Sink Pt. 1

Electric vehicle controllers produce a lot of heat, and their performance is greatly affected by how hot they become. The Electrocraft controller is mounted to a thick U-shaped piece of Aluminum to help distribute the heat, but it didn't have any fins or fans to help air flow pull the heat away.

From reviewing other converters build pages, it seemed most of them added additional cooling to their controllers (regardless of the manufacturer). The top of my controller is really just a thin aluminum cover to keep the internals protected from the elements. It's not used by the controller to distribute heat, so there isn't much purpose in cooling it. Ideally I would have mounted the controller upside down so I could mount the heat sink / fans on top, but hind sight is 20/20 and I can't change my copper connectors.

The long sides of the controller are part of the U-shaped aluminum plate the controller's electronics are mounted to, so it is beneficial to pull the heat from those. I picked up a couple CPU heat sinks/fans and removed their stock mounting hardware. I then fabricated metal end tabs and cut an aluminum rod to length.

After applying a thick layer of thermal paste, I mounted the heat sinks against the controller and screwed the tabs into place. Not perfect, but it seems to hold pretty well. I'll come back another day and hook the fans to the car's 12V system. I'm feeling a lot better about my controller's cooling with this relatively minor addition.

Batteries are scheduled to arrive tomorrow afternoon via FedEx!

Wednesday, July 29, 2009

Battery Update

The batteries I ordered back in April have cleared customs! They should be shipped out of Oregon this week and arrive at my door shortly thereafter!

What's left:
Battery box.
Battery wiring.
Battery charger.
Controller heat sink.

I think my box is second from the left.

Sunday, July 12, 2009

DC-DC Converter

I finally got around to wiring up the DC-DC converter. It's actually for 120V to 12V because I originally planned to have a 120V nominal Lead battery pack. I'm now only at 96V nominal with the Lithium cells, but I think there is enough overlap in the operating ranges of the batteries and the converter so I should be okay.

Two sets of wires from the converter. Red / black for input. Green / blue for output.

I wired the input to include my fuse and circuit breaker on the positive side so it will have a bit more protection. On the negative side, it is wired after the key contactor; so the 12V battery will not start charging until the ignition is turned on. I was debating on whether or not to have it connected at all times or just when the car is running. I finally convinced myself that I didn't want 96V constantly running through any of my circuitry (especially when I'm not there) if it wasn't necessary. (The length of the wire from the converter not being long enough to bypass both contactors may have influenced the decision.)

Here's a shot of the DC-DC output going to the primary positive and negative connections on the car.

Last I heard my batteries had arrived at port and were going through customs.

Sunday, July 5, 2009

Stereo Sound

Back on February 16th I installed one speaker into the car. This past weekend I went ahead and built a mount to install a second.

The old mount worked great, so I cut a second one just like it.

The car had a flimsy piece of cardboard "covering" up the wires behind the dashboard. It looked terrible and was in my way so I ended up trashing it. I'll install something better to replace it later.

The new speaker installed!

Stereo sound is good stuff.

Thursday, July 2, 2009

Seats and Horn

Our Australian Shepherd dog is not a pet, he's our child (as you could probably tell in the earlier photos). My wife bought new seat covers for the car to style up the interior a little bit.

The seats weren't too difficult to take out - just 4 fairly easy bolts.

Timber helped me put the new seat covers on.

One side complete. This also was a good opportunity to vacuum out the interior.


The old horn sounded about as good as a frog near his last croak. I picked up one of those novelty aooga horns from the auto parts store to replace my old one. I actually received a new horn for Christmas that has a variety of sounds you can play (and record your own), but it turns out it can't be wired into the car's existing switch. I'm hoping to take the car to shows though so I'll definitely plug it in for temporary use then.

I removed the two old horns but left the bracket for my new one.


The horn works great, but I'm a little disappointed in its "aooga". I was hoping to hear something a bit more ridiculous, but it's okay.

On a side note, my cordless drill battery charger was no longer charging its batteries. The spring style connectors wouldn't maintain contact with the battery terminals, and it refused to charge. Replacement used chargers on e-bay are like $30, new ones are impossible to find, and its constructed such that it's impossible to open up and repair. I do think companies purposely design their products to have a short shelf life. I however, refuse to buy an entire new drill set just because the charger is finiky.

So, wa-la, it's fixed!

One small victory for the consumer!