Undervolting KT Controller = Feeding 48V in 72V Controller?

[gomyles]

Hi there everyone,

I'm trying hard to source a 60A 48V KT Controller but I am not having any luck.

I have a 72V 60A KT Controller and it was paired with the 72V KTLCD3 Screen.

If I connect the 72V Controller to a 36/48V Display, and program it for 48V, will it allow the controller to run at 48V?
Or is there an inherent Low Voltage Cutoff in the hardware of the controller that won't allow below a certain voltage?

I would try it but I just don't want anything to pop. Logically I think it should be fine? But this is an area that I am undereducated on.

Any insights would be very helpful.
-Myles

 

[amberwolf]

depends on the specific controller.

there is a low voltage power supply lvps that converts the battery voltage to 12v and 5v. some of them have a wide range input, but most do not, and only work at the designed voltage range. some of those you can change the large almost-pencil-thick resistor(s) on the input to something lower (you can calculate it based on the voltages and the existing resistance). some of them are smps designs and would require reverse engineering to change.

some may also have a hardware lvc, usually a resistive voltage divider, and that you'd have to find and change.

 

[gomyles]

I guess there is no harm in trying to hook it up then? I'm not going pop any capacitors or anything right? If the LVC has been hit it just won't power the motor right?

Thank you very much for your response by the way

 

[amberwolf]

it shouldn't damage anything...it just won't work if the voltage is too low.

 

[0x0ddAF]

Hey Gomyles, did you try it? Curious to know how it went, I have the same problem now. Pls share