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Old 10-26-2010, 09:23 PM   #3906 (permalink)
The Toecutter
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Join Date: May 2010
Location: Ghettoville, USA
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Rebellion - '16 KMX Framekit Custom electric velomobile
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I took a look at snakub's truck today.

Earlier in the day, he had it on a lift. He had used a programmed arduino board as a temporary 'control' system and it worked perfectly fine. The rear wheels spun while it was on the lift, at 168V(battery; Exide Nautilus 12V flooded).

He took the arduino board off and put in the ReVolt control board. This time, it 'worked', and the yellow light was not blinking. On the lift, he accelerated, and then a transistor blew with very little throttle applied.

He then connected a 24V pack and ran it on the lift with the ReVolt logic board. It worked, although 250A was being drawn just to spin the wheels. We tried this at 36V, 48V, 60V, 84V, and 108V. After 108V, we discovered a bad battery that was reading 6 kohm resistance and removed it; at this volyage level, voltage of the pack was dropping to almost 0 with very light throttle. After removing this battery, current draw was very reasonable at 108V. We checked all connections and they were good.

At 156V, we measured the resting battery voltage at ~160V, and we ran the truck on the lift, and the rear wheels spun with no issue.

We then lowered the truck, put it in reverse, and backed it a few feet. Then we put it in second, and began going forward; a jerk ensued for about 1/3 a second and the transistors in the controller blew. The batteries also began to smell horrible and read ~80V at rest, for a 156Vnom pack.

I suspect that the control board, for whatever reason, is acting as an ON/OFF switch under load. Could this be indicative of a bad ATMEL microprocessor or faulty programming within? The power section of the controller used to work fine with the arduino board, but without all of the safety features that you want a PWM controller for(hence why he ordered the ReVolt logic board kit). I'm thinking that the ReVolt logic board is trying to tell the power section to output max current under load; the truck jerked somewhat violently to indicate this, and the transistors blew, along with the batteries being cooked(they are intended for like 250-300A) indicating that the overcurrent protection is not working.

The yellow light for the logic board, even after all of this, still comes on, as a solid yellow color.
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