Monday, November 8, 2010

Back on the EV road

Haven't had an entry in a while.  When last we spoke I was dead in the water because of a broken shifter bushing.  Here's what it looked like when I removed the center console (bits of black plastic under the shifter is what remained of the bushing - the brown ring at the end of the cable coming from the right side of the picture is where it should have been).
I found a replacement bushing on eBay for $17.  It took a few days to arrive, but all of 45 seconds to install.  Here's a picture of the bushing snapped into the cable-end ring.
Here is the cable end with bushing snapped on to the bracket connected to the shifter.
And the view from the other side.
Since replacing the bushing, I've put about 400 miles on the car commuting to and from work.  The shifter feels great.  However, I am still concerned about the vibration coming from the drivetrain, so I am now in the process of taking everything out of the engine compartment so I can get the motor-transmission assembly out for diagnosis.  More on that later.

Friday, October 15, 2010

The excitement after the lull after the excitement

Well, after I said that the tread on the tires wasn't too bad Murphy started making himself known.  Two of the tires started leaking: one because the rim is so corroded, and one through the valve stem.  So I enlisted the help of Tire Rack and in 2 days 4 new wheels showed up at my doorstep, freshly mounted and balanced and ready to go on the car.

Getting insurance was actually more difficult than I expected.  My current insurance agent (AAA through Commerce Insurance) refused to cover it because the conversion was not done by a professional.  I called a few other agencies that other converters have had success with (Progressive, Farmer's, MetLife) to no avail.  Finally, I asked the advice of an acquaintance a few towns from me who is driving a conversion, and he gave me the name of his insurer (Liberty Mutual).  They had no qualms about insuring my conversion, so I switched all my auto insurance business to them.  Not only that, I'm now paying 20% less even after adding this car to my policy!

Once the insurance was squared away, getting plates was a no-brainer.  The insurance agent filled out an RMV1 form for me, specifying that it now has an electric powertrain.  I took that and the Title with the purchase info on the back (from 2009!) and took it to the Registry.  They didn't look at it twice.  Took all of 30 seconds to get my plates (most of that time was filling out the check!) and I was on my way.

Of course, once I went to get it inspected I realized that I should have asked a few more questions because the computer still thought the car was gas powered.  Oddly enough, the technician could change it right there on his computer.  Who knew?

The inspection experience was interesting.  I went to the gas station where we've gotten all of our cars inspected for 10+ years (thinking it might help to have some experience with the guy), and I explained to him that it is now totally electric and that although it is a manual transmission he could treat it as if it were automatic.  That was surprisingly hard for him to understand.  He kept trying to feather the clutch to get the car started!  But he eventually got it into the inspection bay and punched in the license plate number into his computer.  That's when we realized the Registry had not done their job right when the registration was entered.  But once he made the change on the computer the safety part of the inspection went easily enough, and the sticker went on the window in no time.  Of course, by then all of the mechanics were gathered around the car asking questions so I popped the hood and showed them the engine compartment.  I couldn't really tell if they were impressed with my handiwork or just thought I was crazy.  When I pulled out of the station they were all standing at the inspection bay door watching - wondering if it would actually be able to avoid getting hit? - and I waved out the window as I left.  See you next year!! (but not before..... heh, heh)

So here I am at home sucking juice out of the wall.

And at work.

Things were going so well!  Then Murphy again knocked at my door.  I was tooling around town with a friend (he's helping me work out a way to interface the dashboard tachometer with the DMOC motor controller) the evening after my second commute to work (yes!) when the shifter went slack (no!).  Fortunately, it was still in gear but the shifter lost all contact with the transmission.  So I pulled over to the side of the road and quickly determined that the connection between the shifter and the shifter cables were gone.  So I limped home (boy, acceleration is poor when you start out in 3rd gear!) and took the center console apart.  The bushing that held the main shifter cable to the shifter rod was in pieces and scattered about.  Well, at least it wasn't something that I had done wrong during the conversion - I never touched the stupid thing!

Of course the dealer sells the bushing only with the entire cable ($216!), but thank goodness for eBay.  Apparently these bushing fail all the time and there are people who sell machined parts (<$20) to replace the poorly-designed originals.  The only downside is that they have to ship it to me, so I'm spewing fumes to get to work again.  But hopefully not for long.

Friday, October 1, 2010

The lull after the excitement

After those heady days leading up to the Coupe de Volt's maiden voyage, the last few weeks have been a bit of a letdown.  But I trudge forward and am getting things done.  Progress has been made on a number of fronts:

Fixing stuff that's broken: the burnt out headlight and fog light were easy enough to replace, but the backup lights took a little more effort.  I quickly determined that the bulbs were fine and that the problem was in the "back-up light switch" on the transmission.  Fortunately, it was very easy to replace ($15 at Autozone) so I now have working backup lights.  I think the car will pass the safety inspection now (tires are loud but the tread is good so I think they'll be ok, and the alignment isn't that bad).

Battery monitoring: I had previously run 3 wires from the batteries in the front of the car to the rear of the car for the PakTrakr, so the next step is to splice in to those wires to make the connections to the batteries and the PakTrakr remote module.  Each remote monitors six batteries, so I needed 3 remotes to monitor my bank of 13.  The instructions for connecting the batteries to the remotes were straightforward, but it was a little confusing at first as to how to connect the 3 remotes together and to the display.  After a bit of trial and error I finally got it right.  The correct wiring scheme goes like this:
Wire #1 from each remote (to be connected to the negative terminal of the lowest potential battery in the series for that remote) has an in-line fuse soldered to the lug.  So because "Battery #1 is in the front of the car I had to splice that lug/fuse into the wire that I had previously run through the car.  That was really the only tricky part to connecting the PakTrakr wires to the batteries.

Slight modification to the battery box vent: I placed the vent hole in the back of the battery box as high as I could without cutting into the steel frame, but the hole was actually below the top of the batteries!  So I constructed an air dam to draw air from the top of the box.  The air dam consists of a few layers of plywood which are glued together then screwed to the wood.  Here are a couple pictures:

Friday, September 10, 2010

On the road!!!

I had finished the dash gauges and the battery connections on Tuesday, and considered if I should try to run the car or not.  I was a little squeamish about doing the "smoke test" and wondered whether I should push the car outside the garage so it wouldn't take the garage with it when it caught on fire.  But the garage owner convinced me to do it, sooooo....
  1. Connect the accessory battery.  No smoke.  No blown fuses.
  2. Connect the Anderson connector to put the traction battery voltage to the DMOC.  No smoke or sparks.
  3. Turn the key to the "on" position.  The usual warning lights come on then go off except for "service engine soon" (yep, better check that!) and "low fuel" (no gas here!).  The vacuum pump runs for about 8 seconds, then shuts off.  Other than that, nothing.
  4. Put it in neutral.  Press on the accelerator.  Nothing.  No spinning sound.  Bummer.
  5. Hook up the laptop to the DMOC.  Read the ccShell instructions.  1st thing it says to do is load the .ccs file that came with the DMOC.  Oops.  I forgot to bring the file!  Go home with my tail between my legs.
Next day, Wednesday.  I've loaded the .ccs file on the laptop and all I think about all day at work is getting to the car and trying it.  I've also thumbed through the ccShell manual (interface software for the DMOC).  Yeah, I know.  I didn't read the manual before I started - who does?  Anyway, in the manual it says that there are 4 things that have to happen before the DMOC will spin the motor, after the main contactor closes.  Hmm, I never heard the main contactor close last night.  Reading on, I see that the controller comes configured to look for a "Drive Enable" signal before closing the contactor.  I don't remember seeing that signal in my ElectroAutomotive instructions.  Apparently it's a signal that is used when connecting the motor directly to the differential (no transmission).  There are instructions on how to configure the DMOC to bypass the "Drive Enable" signal.  Now I'm antsy to try it.  So I sneak out of work as early as I can and .....
  1. Connect the laptop to the DMOC.
  2. Turn the key on.
  3. Check the "Drive Enable" configuration.  Yep, it's looking for the signal.
  4. Disable the signal, save the parameters.  I hear a nice ka-chunk as the contactor closes.  Yes!
  5. Disconnect the laptop, close the hood, get in the car.
  6. Put it in neutral.  Press on the accelerator.  I hear spinning!
  7. Put it in reverse.  Back out of the garage.  I'm moving!
  8. Put it in forward to drive out toward the road.  Nothing.  I feel a little rocking motion, then the motor kicks out.  Reverse, 1st gear, 2nd gear, doesn't matter.
  9. Put it back in neutral.  Motor spins.  Hmm.  Transmission problem?
  10. It's late and I have to go.  So I get some help and push it back in the garage.  That's a bummer.
Here's the car while I'm trying to go forward.

Later that night I do more reading.  There are a number of variables and parameters that could cause the motor to cut out, related to torque limits, current limits, what have you.  I figure I'd better connect the laptop again and see what the DMOC is saying.  The next day I'm anxious all day.  It's almost as bad as when my wife was expecting - the anticipation is killing me!  As soon as I can, I get over to the car again.
  1. Connect the laptop to the DMOC.  This time I use a longer serial cable so I can run it out of the hood and through the open passenger window so I can keep communicating with the DMOC.
  2. Turn the key on.
  3. ccShell says the last error was #16, PS_FLT_CHARGER_ERROR.  Apparently it's an error related to inadequate grounding or shielding.  Hmm.  It also says that in subsequent revisions of the software this error has been deleted, and can be ignored by setting a variable.
  4. I set the variable to ignore the error.
  5. I get in the car, put it in reverse. Back it out of the garage.  So far so good.
  6. I put it in 1st gear.  Forward motion!
  7. I drive out toward the road.  I slap on plates from my other car.
  8. I drive to a friend's house.  We chat.  I show him the car.  I drive home.  I turn the regen on, then off, then on, noticing how it changes the driveability.  I like it when the ammeter shows negative amps.  Recovering energy - cool!  All in all a 4 mile trip, speeds from 30-45 mph.  Very satisfying.
Here's the car in the driveway after my successful forward motion.
Maiden voyage complete!

So, my take from the experience.
  1. The EV grin is real.  And very satisfying.
  2. Pick-up was not great.  I was able to get up to speed, but it took longer than I liked.  On the other hand, I noticed that I was never pulling more than 150 amps.  The paperwork says that the max current is just under 300 amps, so maybe it comes tuned down at first and the pick-up can be improved?
  3. The car needs some (non-EV) work.  Back-up lights don't work, one of the headlights and fog lights are out, the tires are LOUD, it needs a front-end alignment, and there is some noise/vibration from the drive train (transmission?).

I'm off for a week now, taking my daughter to her first year of college (in IL), so nothing's going to be done for a while.  Next steps: fix the broken things, install the Pak-Trakr (battery monitoring), finish the dash switches (that control the cabin heater and DMOC regen settings), install the battery box lids, and get the car registered!

I'm excited and motivated again!

Catching up - battery connections and dash gauges

I've been neglecting the blog lately (again), but have made progress.  And last night, yes, the car went on the road for the first time!  Very exciting.  Still much to do before it'll pass inspection, though.  More on that later.

Battery connections:
In order to make up the battery cables, I "splurged" and bought an el-cheapo hydraulic crimper from Harbor Freight and went to town.  Following the instructions from the ElectroAutomotive kit, I cut back the insulation on the cable, filled the lug with Noalox, inserted the wire, crimped it, slipped a piece of heat shrink tubing over it, heated it up to shrink it down, and voila.  A completed connection.  Repeat 137 times.  Or so it seemed.

Here are a couple of views with the batteries connected.  The big piece of pink plastic tubing seen in two of the views is 1" heat shrink covering the fusible link for electrical isolation.  The same pink heat shrink is covering the main tie-down for the lower box - during installation that steel tubing has to come very close to terminals!
Next I made the connections to the main shunt and the motor controller.

Dash gauges:
For the 3 gauges supplied with the kit (traction pack current and voltage, accessory battery voltage) I bought a generic 3-gauge pod that mounts on top of the dashboard.  Nothing spectacular here.  I ran the wires up from under the dash and through a couple of small holes drilled in the top of the dash.  For mounting the pod I cut out a small piece of aluminum (.1" thick), drilled and tapped holes to match the mounting holes on the pod, and sandwiched the dash skin between the aluminum and pod.  Very solid.  Here are a couple views of the installation.  Sorry for the dirty windows.

Monday, August 30, 2010

Completing the main battery box

The batteries have been loaded into the main battery box.  Here's how it went.

I previously showed connecting the exhaust vent and fan to the rear of the box and to the back of the trunk.  On the front side of the box I had previously made a cutout for the battery cables to run through.  Using a hodge-podge of electrical and plumbing fixtures and adapters, I cobbled together something which connects the conduit which I had previously installed in the hump and the front of the battery box.  Here's a picture of the hodge-podge in place.
Next I caulked around the edges of the wood pieces inside the box.  I will probably regret this later when I decide to rebuild the box, but I used silicone caulking (white, no less).  Hopefully it won't be too ugly to remove.  Once that was cured I started loading batteries, starting with the batteries in the rearmost positions.  It was a pretty awkward situation, and since the batteries weigh 87 lbs each I could not lift them into the back box.  I considered some elaborate hoist that could levitate the batteries into position, but then snapped out of it and placed a piece of plywood to act as a ramp from the forward lip to the rear of the box.  Worked like a dream.
I had previously designed battery tie-downs to keep them from jumping and sliding around while I'm driving, but I also want to constrain them from the bottom as well.  I bought some rectangular HDPE extrusions (3/8" x 1") to use as guides - I figured I'd screw them in to the bottom wood to give myself a positive stop when positioning the batteries.  Here's a view of the guide at the back of the box.
Here's a view of the "side guide" for the back of the box.  I hung this one from the side because the gap was too narrow to use the full width on the bottom.
Here's a view of guides that are just wedged in between the batteries.  (Not a press fit, just snug)
Here's a view of the front guides in the rear section.
I used the same technique to create guides in the front section as well.  Some screwed into the bottom wood before the batteries are installed, others slid into place after the batteries are loaded.  In this case, the batteries were designed to be snug against the front wood so no shims were required there.
With all the batteries in place, it looks like this:
Here's a close-up of one of the tie-downs:
So, now that the car is fully loaded I can see how good my calculations were for the strength of the new rear springs.  The rear end is about an inch taller than the front.  Not too bad.  I may have to adjust those at some point - just have to wait and see how it looks from a distance.
Next stop: battery cables.

Wednesday, August 25, 2010

Battery box ventilation

In order to remove hydrogen gas and other unpleasant odors which might be generated by the batteries during charging (and possibly discharging) I wanted to install a ventilation system.  The overall plan is to be able to seal the battery box as much as reasonably possible and then vent the box through a hole somewhere in the back of the car.  The fan should be installed as far downstream as possible to minimize the "positive pressure" parts of the ventilation; that way if there are leaks air will be drawn in to the box rather than out into the passenger compartment.

Step 1: cut a hole in the back of the battery box (as high as possible without compromising the structural integrity of the box, i.e. don't cut into the metal).

Step 2: cut a hole in a convenient place in the back of the car.  In my solution to this problem, I cut the hole in the back of the spare tire well, the only place I could find with a reasonably flat section for the fan assembly to seal against.  View (upside down) from inside of trunk.  So, the fan will blow air into the space behind the bumper cover.

View from behind the car (bumper cover removed).
 Step 3: make a fan sandwich between pieces of plywood.  A double thickness of plywood was used on the "upstream" side of the fan so that the wood pieces contacting the fan could have an opening as large as the blade diameter.  The hose being used to connect the box to the fan is smaller in diameter.  The bottom plywood is larger to leave room for screws to attach it to the trunk wall.  The sandwich is held together with #6 machine screws threaded into "T" nuts driven into the back side of the larger plywood.

Step 4: attach the large plywood to the back of the trunk with sheet metal screws so that the wood cut-out is sitting directly over the hole cut in the trunk wall.  Since this joint will be positive pressure, I used a thin silicone gasket to ensure it is air tight.

Step 5: create the fan sandwich and attach wires to the fan (power taken from cargo light [always on], ground wire attached to ground terminal in rear enclosure).  The joint between the fan and the large plywood is also positive pressure, so another silicone gasket was used here as well.

Step 6: cut the rib off the end of the hose fittings and jam them into the holes (battery box and fan sandwich).

Step 7: connect the accessory battery, and confirm that the fan is blowing out of the back of the trunk.

Air flow confirmed.

Wednesday, August 18, 2010

The Saturn has landed!

Major milestone!  Not to say that they'll not be coming off again, but for the first time since April 2009 the Coupe de Volt is sitting on wheels again.
No batteries in the back yet, so my mega-stiff springs in the rear are holding the car up high!

Note to self: Those aluminum wheels are looking pretty scuzzy.

Batteries in radiator box

Two of the batteries are in place!  Because of the placement of the front battery box (where the radiator used to reside) it is not possible to load the batteries in from the top.  So the box is designed to be loaded from the bottom.  Here's the 2 batteries loaded on the box bottom.  Have to be careful to keep them balanced on the jack!
Next, I pushed the jack under the car and start pumping.  It was a little tricky aligning everything on the way up (partly because the jack doesn't lift straight up) but it fit eventually.  In order to hold the batteries in place, I put little pieces of 1" square tubing (painted with epoxy and with the ends closed with polyethylene caps) across the top so they get sandwiched between the battery and the top rail of the box.  It's a little tough to see in this picture, but the tubing is set in between the trio of filler caps.

Here's a view of the loaded box from the bottom.  The bottom of the box is actually about an inch above the bottom of the bumper, so I shouldn't have any problems with ground clearance.
Ready to be wired.

Monday, August 16, 2010

AC wiring

My plan was to use the "fuel filler" area for getting AC power to the battery charger.  Because the body panels are plastic, mounting options for the receptacle are limited.  The only real solid place to attach a receptacle is a single "speed clip" attached to a metal bracket in the upper right corner (where the original gas tank filler pipe was attached).

I cut a crudely-shaped piece out of some scrap aluminum sheet (1/8" thick) and cut a hole in it to accept the body of the receptacle.  I drilled and tapped 3 holes situated around that hole that matched the mounting hole pattern in the receptacle flange, and then drilled a clearance hole for a #10 machine screw to mount the aluminum piece to the metal bracket's speed clip.  Once mounted in place, it looks like this:

It's an L14-30 receptacle.  I chose the L14 style because I wanted a turn-lock style (as opposed to the dryer style) for a more secure connection and I decided it would be a good idea to bring in a neutral line in case I have components on the car that run on 110VAC.  Like, for instance, a little trickle charger for the accessory battery, or blanket-style battery warmers.

So, from this receptacle I ran 4 10AWG wires (2 black wires for the hot lines, a red wire (with white electrical tape wrapped around it - I ran out of white and had plenty of red) for the neutral line, and a green wire for ground) through the body at the top of the inner fender wall and into the rear electrical enclosure.  Here's a view from behind the receptacle:
I'll wrap the wires and the back of the receptacle to protect them from the elements.  Here's a view of the wires coming out of the fender wall:

Here's a view of the fully-wired rear enclosure:

I have the power coming in from the right side and leaving the left.  The blue and red wires are the AC input to the Zivan NG3 battery charger.  There is an additional green wire that connects to the chassis and serves to tie the chassis ground to the AC power ground line (earth) while it's plugged in.  Two of the small black wires connect the AC power to the Primary AC Interlock Relay in this enclosure while the others run between this relay and the other relays in the relay enclosure in the engine compartment.