ProEV - Electric Imp Test Log #1

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Electric Imp Testing Log

April 17, 2003 -Thursday

Testing Begins: All the wires are properly connected. The computer is on and running the SIADIS program. I switch on the Emergency power switch and turn on inverter #1. There is a quiet humming from inverter #1. The SIADIS program goes from <No Data Received> to <Communication OK>.

The Message box displays, "OK / No Start Command".

I press the start button. There is a loud 'CLACK' as the high power contacts close. The Message box reads to "Drive Mode".

I click the three position switch from neutral to forward and twist the potentiometer. An instance hesitation, then the front motor begins to spin.

The front motor is not yet connected, so it spins up quickly. I release the pot and the motor slows and stops. Next up is the rear motor. It is connected through a differential to the wheels. I check that the wheels are off the ground and free to spin. I shut down the inverter #1 and connect the serial port of the computer to inverter #2. I shut down the SIADIS and restart it as a precaution.

Switch on. ...The inverter hums.
Press start button. ...The high power contacts close.
Switch to forward. Turn the pot. ...Nothing.
I wrestle with the strong spring built into the potentiometer and turn it further. There is a loud sound and then the wheels are spinning. I spin them for about 5 seconds and then release the potentiometer and they stop. It's Alive!

Or so I thought. I decide to spin the rear motor again. I turn the pot and instead of the wheels spinning, I hear a load "clack" as the high power contacts open. "Why?"

I shut everything down including SIADIS. I restart everything in the proper order.
<Connection OK> but instead of the "Drive Mode" message, I see "Prech. Time > 3s" and "VC_Under_Voltage". What has gone wrong?

I shut everything down and get the multimeter. The pack reads 385 volts, slightly above nominal (178 batteries X 2.14 volts = 380.92 nominal). This makes no sense.

I try the front motor. It does not work and I get the same message. I knew this was going too smoothly.

I call Victor from Metricmind.com and we consult over the phone. He suggests some things to check but since they involve extensive rewiring I hesitate to try.

April 18, 2003, Friday - It's the batteries, stupid!
April 19, 2003, Saturday - Small Steps.
May 5, 2003, Monday - Keeping the Motor from Braking.
May 6, 2003, Tuesday - Slowing with Regenerative Braking.
May 8, 2003, Thursday - Better Regen.
May 9, 2003, Friday - The first test drive.
May 10, 2003, Saturday - Upping the Amps 1.
May 12, 2003, Monday - Upping the Amps 2.
May 13, 2003, Tuesday - Upping the Amps 3.
May 14, 2003, Wednesday - The pack is put on charge.
May 15, 2003, Thursday- Slow Going.
May 20, 2003, Tuesday - Battery Killing.
June 2, 2003, Monday - Onward.
June 5, 2003, Thursday - Another battery bites the dust.
June 7, 2003, Saturday - Checking the charge.
June 10, 2003, Tuesday - Darwin thins the herd.
June 11, 2003, Wednesday - 10 mile run.
June 13, 2003, Friday - Getting the motors to work together.
June 16, 2003, Monday - Balancing the motor draws.
June 17, 2003, Tuesday - Align the car.
June 21, 2003, Saturday - One step forward, one back.
June, 2003 - April, 2004.

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