EV Trans Am

Granted, all it did all day was sit there, but it did at least go.

After last night’s unadventurous drive to dinner I opted to fill ‘er back up and make the slightly longer trip to work, about 15 miles round trip. I took the back roads to keep it under 45 since I was engaged in traffic.

Went 15 miles, voltage when complete was 154. Starting was 168 so it did pretty good as far as range. Charging back up now. It’s been about 3.5 hours at 13.5 amps so we’ll see where it is.

Tonight we went out to a pizzeria that is 5.8 Google miles away. The pack wasn’t quite topped off from a quick lap around the neighborhood the other night so we started at 166 V. Finished voltage was 155.3 so we used 11V to go 11.6 miles, about a volt per mile which is easy to remember. I don’t understand why everyone says 300 watts per mile, I suppose because pack voltages vary.

So instead of saying I need 300 watts of power to go 1 mile, to me it makes more sense to say I’ll consume 1 Volt to go one mile. Voltage is potential so I like the idea of saying I’ve got 30 volts to use at 20% discharge so at 1 V/mi I can go 30 miles. Less as the pack is depleted, but about that.

Besides, who has a meter for watts installed in the car to tell them how much fuel is left, seems everyone uses a voltmeter for “fuel” and an ammeter for instantaneous use.

So after the clunk videos we opted to be brave and took Trans Amped to dinner at Route 46, about 2 miles away with backroads we could take.

For those without a Trans Am, when the weather looks like this you take the t-tops out and go cruising. Just like the good old days but all electric.

Now I’ll get technical. We figure we went about 4 miles. The batteries weren’t fully charged because of the earlier testing in the neighborhood (I did that about an hour before dinner) so the pack voltage was about 172 while charging, so probably 168 resting. After the 4 miles the measured voltage was 162. so if we used say 8 volts to go 4 miles I can take the pack down to 125 (80% of 156) that means I have about 45 volts worth of safe go juice. At roughly 2V per mile that means I’d be able to go 22.5 miles. I’d expect the mileage to decrease along with the pack voltage though so probably a little less. Yay onboard charger! This is the lowest the pack has been so I’m interested to see how long it takes at 13.5 to recharge. I need to get that 220 line installed. I do have an anniversary coming up soon…

Keep in mind the speedometer and other gauges don’t work (only the ammeter) so I’m guessing at the distances and even the volts. But it’s inline with what I’d expect. Speeds were probably 25-40 mph which is typical for my driving, maybe closer to 45 though. Amp draw in 4th at ~35 mph was a pretty stead 75 to 100. Pushing the pedal a bit more and the amp draw would increase to 800 at the highest I saw. Still haven’t tried full throttle, I’m enjoying it working after a year and a half of build and don’t want to break something just yet.

I’ve got a plan to cleanup the rear battery area by remote mounting the regulators in a box next to the charger.  If I move them I can then seal up the batteries and still be able to see the regulator LEDs flashing.  That will make things look more professional and keep some road noise out.  For the past few test drives we’ve had the center console removed so we can see and hear the pavement through the shifter and the battery racks.

I can also remove the stock power steering pump from the engine bay.  I’ve got one battery that is always last and removing this pump will allow me to access it better to charge it up as a single battery so it doesn’t drag the rest down.  I like the idea of an electric A/C compressor as well, so that would free up a good amount of space under hood.

I’m still nervous about overcharging the batteries so I kept checking on them tonight. All of the regulators had red lights on so I know I need to get the pack charged up and equalized before I do too much more test driving and kill it. It took about 2 hours at 12.5 amps but all but one checked out and flashed green for me. Tomorrow I’ll give it some one on one charger attention to bring it up. The other 12 batteries are at 13.25 V resting, this one is at 13.15 so it’s close but I hate to leave the other 12 regulators in bypass while this one hokey pokes its way up. Total pack voltage is 172V using 13 – 12V DieHard P1.

I bought a crimper and 20 6-pin connectors tonight at Ace, along with a new fuse for the power steering pump.  It blew a 15 amp so I’m trying a 25 amp.  I’ll need to upgrade my wiring to a thicker guage if it’s pulling that much.

So I’ll remake the phone cable connections and flip the wires so that are all “TDBR” – tang down, blue right.

Just thought, I bought 20 because I have 13 batteries.  So I need 26.  Oh wait, I can reuse 13 of them because half of the terminals are correct.  Whew.  My wife thinks I go to Ace to often, plus they are out for now.

Today we made the final connections and turned the key.  Nada.  We fiddled with it for a couple of hours and gave up, planning to call the manufacturer of the controller tomorrow for some verification of the wiring diagram.

Basically I turned the key and the contactors didn’t close.  They are controlled by the Raptor 1200 controller, which precharges the internal components prior to sending the command to the contactors to open, dumping a voltage spike across the capacitors.  It wasn’t sending that command.

We tested the contactors by applying voltage across the leads and they are both operational, good.

I realized tonight that I have two contactors – one positive and one negative.  This is for redundancy and provides two electronic means to shutoff the motor by simply turning the key.  What I realized tonight was that the controller must have a continuous connection to the negative lead of the main pack to precharge.  That means you can’t have the controller running both contactors.  I think if I power the negative contactor off the chassis and key on, then the controller will follow normal sequence and close the positive lead on it’s own.

Tomorrow I will sit at work and watch the clock, waiting to go home and try again.  Tick tock tick tock.

So a few days ago I thought I was going to take a break from working and let things settle down after the whirlwind of making battery racks and mounting so many things.  The good news is I ended up not making it that long.  After a frustrating day on the computer at work (new software that doesn’t work and has to be used) I left early and decided to work a little on the car.  That was a Thursday and things clicked off pretty well.

So roll forward to last Saturday and I woke up early and went out to wash the gas-car.  I found that there were little specks all over it making it feel kind of gritty.  I hadn’t washed it in a few weeks so I attributed it to road grime but after closer inspection I found out it was metal dust from all the cutting and grinding on the Trans Am.  So learn a lesson from me and move your good cars further away while working on the ev convert.  Most of it came off with a clay bar but I’ll need to go over it another time or two to get the stubborn bits.  I needed my energy that day to get some car stuff done…

So last Saturday and some evenings this week I finished a bunch of small tasks and actually got a little ahead of myself on some things.  A list:

• Completed high voltage wiring.  I have not connected all the batteries because I don’t want 156 volts humming around while I’m still doing the low voltage, but everything is ready to bolt in.
• Completed and mounted the main control board.  High voltage wiring is complete and installed from fuse to contactor to shunt to controller and from the controller to the motor.
• Installed the DC/DC controller and wired it in
• Completed wiring for the motor blower
• Completed wiring for the power steering motor
• Made wires and a terminal block that will be electrically live with key on and tied all my relays into that.

So I said I got ahead of myself.  Today I removed the main control board after scrapping my hand up one too many times.  I thought I could install the battery regulators just reaching under it but it was a pain.  While I have it out I completed the 6 guage wire wires that will connect the charger to the most positive battery up front and most negative in the back.  I bought two lengths, 10-ft of black and 5-ft of white.  Thinking that I had wire to spare I cut off about 1.5-ft of the white to use to tie the DC-DC converter to the negative battery post.  That left me with about 2″ to spare when I ran the wires from the front to the back.  I had to reroute the long wire from one side of the car to the other because it was too short, but ultimately it worked out.  I have another tip to add to my collection for future convertors: While it is a good idea to do a test run of your wiring to make sure it is long enough, you shouldn’t get over zealous and actually attach the wire to the car, especially if you haven’t crimped the lugs on because you don’t know how long the wire needs to be.  I was able to remove only one clip and make my crimp on the side of the car, but it was close.

I also tested my pot box and it seems pretty linear.  I hope the fire didn’t damage it.  Oh, you didn’t know about the fire?  Well I’ll tell you.  I was going off memory and for some reason I thought you had to connect a battery to the pot box so the resistance could be measured.  I did that and connected the multi-meter to the wires that will connect to the Raptor.  Raptor is cooled to say than controller.  As soon as I moved the throttle lever, the battery dumped who knows how many amps into the too small wires that probably shouldn’t have been connected that was anyhow.  So the wires puffed and were on fire.   I blew it out and figured out that a resistor works whether there is a load going through it or not.  So I undid all the connections except for the multi-meters leads and it still shows me 0-5k ohms resistance, pretty linear but a little jumping.  It could have been my unsteady left hand holding the assembly and my unsteady right hand  moving the lever, so we’ll see how it goes once it it mounted to something solid.

I had to edit this one because it was completely wrong.  I couldn’t find the manual for the regulators and the website had a bad link at the moment.  It is fixed now so I reread the manual and see what went I hadn’t noticed before.

I found 12″ 6-pin connectors at Walmart and compared the wiring and they were in the right order.  Problem was when I looked at them through the box the tangs were facing different directions.  According to Rudman, “TDBR” means tang down, blue right.  With the wires I purchased that is true for one but opposite for another.  That makes sense from the perspective of connection a phone to a socket, but not connecting in serial for communication.  I’ll cut off the plastic terminals on the wires I have and recrimp them with new 6-pin terminals.  More expensive than buying a spool of cable and terminals and doing it that way to begin with, but now I know store bought cables probably won’t work.

Made 26 wires today, about 5″ long to run from the battery terminals to the battery regulators.  Regulators are from Manzanita Micro, Mk2d analogs.  They’ll monitor the batteries and tell the PFC-30 when to throttle back so all the batteries take an equal charge without blowing anybody up.

Lots of cutting, crimping, soldering and heat shrinking (with only 1 visit to ACE for more wire and heat shrink), but it took less time than I though.

Also canoed this morning on the Wekiva.  That was fun.