# Which Kelly Controller?



## [email protected] (Jan 24, 2008)

I am looking at buying a different kelly controller for my 90 civic conversion, but I cant decide on which one. I want the most speed. I dont care about acceleration , as long as I can keep up with traffic. I was considering a 120v 600a controller, or a 144v 500a controller. What would be the difference in speed and acceleration for these? I am currently running a 72v system with a KD84600, but dont know if i want to upgrade to 120 v or 144v. Thanks, Jon


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## Mastiff (Jan 11, 2008)

Go for 144 volt if you've got the battery space.

Keep in mind your motor must also be able to handle the 144 volts.

More volts usually equates to a higher top-end speed.

Higher voltage also means more efficiency and less Amperage draw.


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## ww321q (Mar 28, 2008)

Also that 144v will work at lower voltages . You could get it , then just keep adding batteries till you got what you want . How many batteries do you have now and what are the ah & voltage ? J.W.


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## grose (Apr 30, 2008)

I have a controller question that I'm going to sneak in this thread.

Suppose a controller states 144V and 600A. I understand the voltage part just fine. I just need clarification on the amps. Does 600A mean that the controller is able to deliver 600A to the motor (assuming the batteries can provide it), or does the 600A mean that is the upper limits that the controller can take before it fails and something gets fried?


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## ww321q (Mar 28, 2008)

If you read the data sheet you will see something like 600a=1min. 400a=5min 300a= continuous .The amount of amps deliverable to the controller as based on your battery pack . The amps available to the motor is limited to the controller max amps but never more then what is available from the batteries J.W.


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## frodus (Apr 12, 2008)

a controller should never fry if you try to put too many amps through it, it should go into thermal shutdown....

but yeah, most controllers have a limit. Even the zilla has a limit:
"Maximum motor current at 50°C heatsink temperature: 2000 Amps for Z2K, 1000 Amps for Z1K"
"Continuous motor current @ 50°C coolant temp & 100% Duty Cycle: over 600 Amps for Z2K, 300 Amps for Z1K "

I'm not sure if the kelly can hold up to what the zilla can, but I'm interested to see how it fairs. The Logisystems controller quotes 1000 motor amps... but they don't have any specs on how LONG that 1000 is. I talked to the owner at Logisystems and he seemed to say 1000A was max, but he never mentioned how long the runtime is.

I don't think each manufacturer has a standard for rating/derating the temps and amps for controllers. I'd like to see some back to back numbers using the same requirements to measure by.

Most controllers are rated in max amps. We don't know yet if kelly derates that 600A number, but I do know that Cafe Electric derates the Zilla to 50 degrees C. Synkromotive is derating the parts to 100 degrees C. Its all about keeping the semiconductors cool. If you can't dissipate the heat, then its going to go into thermal shutdown.


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## [email protected] (Jan 24, 2008)

ww321q said:


> Also that 144v will work at lower voltages . You could get it , then just keep adding batteries till you got what you want . How many batteries do you have now and what are the ah & voltage ? J.W.


Right now I am using 9- 8 volt trojan t-875's. I believe they are around 175ah. Thanks for the advice. I am more than likely going to go with a kelly KDH14500 controller.


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