Tuesday, July 14, 2009

Getting a new Synkromotive Controller

After mentioning the motor controller temperature faults to Ives (the designer) at Synkromotive, he suggested we swap it out for a newer one. I went into the shop this evening and swapped out the controller. Ives looked at the old one and basically told me that I had beta test unit #2 with tiny heatsinks, bad ventilation and very little filtering on the temperature fault circuitry. Apparently other customers have had the same issues and the new controller should be far better.

One other thing the folks at Synkromotive showed me was a newer vacuum assist pump for the braking system that's very quiet from EVComponents. It's a bit expensive, but the pump produced very little noise, even with the hood open and my hear near it. Also, to enhance the power steering, they use the electric power steering pump from a Toyota MR2 so that parallel parking isn't as hard. More info here.

So far, the new controller is doing just fine. It also got bumped up to 700 motor amps from 600 when starting from a stop. The tires do a wonderful little "chirp" when I floor it from a stop in first gear before the batteries current maxes out at 300 amps. I could kick both of those up, but choose not to so I can save breaking my transmission and batteries.

I'll try and keep y'all posted on the progress. I'm a bit tired of working through issues right now, so if the car drives well, you might not hear from me for a few weeks.

One other complaint I received was that the open-source Civic plans were not complete on the Civic-EV Google Group. The complaint is valid and I plan on finishing things when the summer is over and I'm past my burn-out stage on this project. I hope to just enjoy driving the car for awhile. The modified charging circuit seems to be doing its job well and I'm happy that problem is over.

In the meantime, I'll be attending the Wayland Invitational at PIR to rub shoulders with the bigwigs in the EV industry at the end of July.

Sunday, July 12, 2009

EV Awareness Day, Synkro faults

Yesterday was our local EV organization's big annual event called EV Awareness Day. We held it at Pioneer Courthouse Square in downtown Portland. I gave a press event with the Mayor Sam Adams and two VPs from local power companies (PGE and Pacific Power).

Probably one of the coolest things about the show is that a Tesla Roadster showed up unexpectedly!

Here I am with the Tesla Roadster.

After talking about electric vehicles to people all day in the sun, I was rather fried at the end of the day.

On the way home the Sykromotive controller faulted three times during initial acceleration up a hill in the summer heat. I suspect these are temperature glitch faults that Synkromotive has been having issues with for awhile. Being fried from the show and caught in heavy traffic on a hill with lines of people behind me, you can imagine this wasn't much fun. Fortunately, I've learned that I just need to toggle to ignition key and wait five seconds to try again.

After clearing the third fault on this hill, I was able to very slowly accelerate up the hill until the motor turned enough to not cause noise issues with the temperature sensors in the controller. I'll be uploading all the fault logs soon and contacting Synkromotive for further advice. Other than the temperature faults, the controller has been excellent. This is still a "beta" unit, so perhaps they've resolved the issues. Let's hope so...

Thursday, July 9, 2009

Super FET working Comments on Sykro Controller

Last week I was mostly on vacation, so I didn't get a chance to really charge the car at full amperage many times. This week was back to work, so I was able to give the charge detector a more reasonable test.

In short, the three huge FETs with heat-sinks seem to work just fine (I should hope so...). I've charged the car seven times in the summer heat and the charger can dump a full 8 amps into the batteries every time without heating up the charge detector box.

I had a little bit of a scare today at work. The Synkromotive controller would instantly fault every time I touched the accelerator. It seems that I had a loose connection between the potbox and the controller. When I wiggled the connector on the TPS (throttle-position-sensor), the controller ceased to go into a fault condition and I drove home. I put anti-corrosion compound on the TPS contacts to help prevent a similar fault in the future. I'll bet that the Sykromotive controller was faulting due to an incorrect input on the potbox wires.

I really like the simplicity of the system. If it fails, it usually fails big and the failure is usually a loose wire somewhere. Get out your Fluke-meter and start debugging.

On my last post, someone left a comment asking about how well the Synkromotive controller was working. In short, it's great. It gives a lot of power when requested and is quite easy to tune various internal parameters through the user-interface over the USB port. Embedded logging makes it really nice as well.

A few nitpicky items I would improve about the controller: The large bus bars that attach to the battery cables are mounted vertically, requiring the use of right-angle lugs or fancy routing of wires. Also, the power given to the motor instantly reflects whatever is specified on the potbox.

If you have a quirky potbox or press the accelerator too quickly, the car seems to lurch a bit. This is especially true if there is slack in the drivetrain from having the motor coast to a complete stop. The lurch instantly takes up the slack in the drivetrain and you can get a jerk that might cause oscillations.

As I've mentioned before, the big solution to this is to use the factory TPS instead of a cheap forklift potbox (like a Curtis PB-5 or PB-6). The factory one is much smoother and more reliable. The downside of the factory potbox is that it never goes to zero ohms which means you can't use it for simpler controllers like a Curtis. The Synkromotive controller has many potbox tuning adjustments so you can set the zero point and the acceleration ramp depending on the travel distance of your throttle cable.

The Synkromotive controller on hot days sometimes gets a temperature noise fault. More recent firmware tends to fix this issue, but I've still stalled once with the latest firmware. Fortunately, you simply need to toggle the ignition switch and wait four seconds for the precharge circuit to run to re-engage the contactor before driving again.

This weekend is the biggest day of the year for our local EV club. We're showing off 30 electric vehicles in Downtown Portland and Mayor Adams is also showing up at our press event to endorse our group. I'm excited but will be happy when it's all over.