ProEV - Electric Imp Test Log #5

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Electric Imp Testing Log

April 17, 2003, Thursday - Testing Begins.
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: Next up, I want the regenerative braking to be controlled by a separate potentiometer, which we will call the regen pot. The wires are identified in the manual.
I wire them with the same type and gender of plug that the throttle pot is wired. High, low and wiper go in the same order. This allows me to use the spare throttle pot as a regen pot for a test.

In parameter 300 Mode_Selector, bit 3 controls whether the regen is on and can be controlled by a variable analog signal. It needs to be set to '0' for brake demand via potentiometer, so it needs to be changed. Bit 4 set to '0', gives the brake signal priority over the throttle signal, so that if you press the throttle and regen at the same time, you will slow rather than accelerate.

I spin up the front motor with the throttle pot. Then I twist the regen pot. The motor slows rapidly and I_bat shows a negative figure. We have regen.

I experiment some. Little twist of the pot, a little regen. Mild slowing and low amps back to the battery. Big twist and high amps. Suddenly there is a "Clack". The front motor is still spinning and the pot is doing nothing. There is an error message of 'Overvolt analog'.

The batteries are almost fully charged. When I asked for full regen, the inverter tries to oblige. It raises the voltage too high and then shuts itself down to protect itself. The motor just free spins down.

I 'reboot'.
Switch to neutral.
Off/On the inverter switch.
Push the start button.
Switch back to forward and we are good to go again.

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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