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Hello fellow electric car enthusiasts!
My name is Charlotte and I’m an undergraduate intern hoping to get some help debugging a problem we’ve been having with our recently converted car.
We have a 1972 Volkswagen Karmann Ghia. We are using 24 Second Gen Nissan Leaf battery modules which produce 90 V nominal. The motor is a D&D ES-15-6 which runs 9HP at a continuous 72 V.
We have a CURTIS 1253-8002 (EVC255-8002) 80V Motor Controller (designed for a forklift) and have gotten it reprogrammed and inspected and supposedly has no faults.

The issues we are having are the following:
- When starting the car in a high gear, there is significant shake to the motor.
- When hitting a certain speed or trying to go uphill, the car’s power will shut off.
- The motor controller box tends to get hot and has at times shut off.

We are trying to find the source of the problem and are wondering if the motor controller is the source of the problem.
We have tried replacing the motor and had the same results.

Does anyone have experience with this motor controller or the 600 AMP version?
Or can anyone recommend a place to start investigating based on the issues listed?

Any advice or opinions would be very appreciated!
Thanks in advance :)
 

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We are using 24 Second Gen Nissan Leaf battery modules which produce 90 V nominal.
Leaf modules are 2S 2P in configuration, so they have a nominal voltage of 7.5 V each; there are 48 modules in the Leaf, all connected in series, for a 96S and 360 volt complete pack. 24 modules (a half-pack) would be at 180 volts, nominally, if connected in series; it appears that you have paralleled at the module level, or have two parallel strings of 12 modules each... that would result in 90 volts (nominal).

The motor is a D&D ES-15-6 which runs 9HP at a continuous 72 V.
Keep in mind that the motor only sees the full 72 volts under limited conditions; normally the controller is supplying a lower voltage to drive the desired current at the current motor speed.

The power rating is what the motor can handle continuously, without overheating. While the rating is at 72 volts, given the 90 V (nominal) battery the controller could deliver significantly more than 72 V at full "throttle"; while 9 HP @ 72 V only corresponds to about 100 amps, you could be using much more current in actual operation.

We have a CURTIS 1253-8002 (EVC255-8002) 80V Motor Controller (designed for a forklift) and have gotten it reprogrammed and inspected and supposedly has no faults.

The issues we are having are the following:
- When starting the car in a high gear, there is significant shake to the motor.
- When hitting a certain speed or trying to go uphill, the car’s power will shut off.
- The motor controller box tends to get hot and has at times shut off.

We are trying to find the source of the problem and are wondering if the motor controller is the source of the problem.
We have tried replacing the motor and had the same results.

Does anyone have experience with this motor controller or the 600 AMP version?
Or can anyone recommend a place to start investigating based on the issues listed?
The 1253 datasheet suggests that this controller (1253-80xx) is rated for 600 amps (for up to 2 minutes). I don't know what the last two digits ("02" in this case) mean, but various non-authoritative online listings suggest that this variant is only rated for 300 A or 350 A.

In that whole description, there is no mention of current, other than the controller's current limit. Problems when starting in a high gear or trying to climb a hill suggest that that the motor is under high load, meaning high current to meet the torque requirement.

So to investigate the problem...
  • Is the controller hitting a current limit, either in hardware, or software, or configuration?
  • Have you monitored the current during normal operation and when the problem occurs?
  • It is possible (but unlikely, because this is such a minimal load for the Leaf modules) that under load the battery voltage is dropping ("sagging") enough to trigger the controller's undervoltage control feature - is the voltage to the controller being monitored, and are the controller's settings known?
I assume that you have the controller manual. Are you using a programming tool, or trying to do this with just the external status LED? :confused:
 
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