# Power supply for a Kelly KBL 120V 250A



## RoughRider (Aug 14, 2008)

my Kelly KBL 120V 250A controller needs a power supply...

it should be: 10-30V...

so my question is: do i need a dc-dc-converter or can i just build a 18V battery and put it directly to the controller?


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## RIPPERTON (Jan 26, 2010)

supply voltage is 18 - 136 so you would use your main battery pack to power the controller.
I have the same setup on my 72v Giant MTB.
I run 80v through a handle bar switch to the precharge resistor.
When precharge volts are up I just engage main contact which is manual not electro.

http://www.newkellycontroller.com/kbl12251h24-120v250abldc-controllerwith-regen-p-198.html


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## RoughRider (Aug 14, 2008)

RIPPERTON said:


> supply voltage is 18 - 136 so you would use your main battery pack to power the controller.
> I have the same setup on my 72v Giant MTB.
> I run 80v through a handle bar switch to the precharge resistor.
> When precharge volts are up I just engage main contact which is manual not electro.
> ...



in the manual for the KBL-series they write: supply voltage is 8-30V for controllers over 72V

do you have a supply power to the pin1 at J2??


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## RoughRider (Aug 14, 2008)

RIPPERTON said:


> supply voltage is 18 - 136 so you would use your main battery pack to power the controller.
> I have the same setup on my 72v Giant MTB.
> I run 80v through a handle bar switch to the precharge resistor.
> When precharge volts are up I just engage main contact which is manual not electro.
> ...



what kind of precharge resistor do you use?


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## RIPPERTON (Jan 26, 2010)

1k ohm
if you got the controller new from Kelly they should have shipped one with it.


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## RoughRider (Aug 14, 2008)

my controller came a year ago without the resister.

how many watts is your resistor good for?


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## RIPPERTON (Jan 26, 2010)

10w...................


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## RoughRider (Aug 14, 2008)

RIPPERTON said:


> 10w...................



thanks for the informations...

and you just use a switch...no relais for the resistor?

how long do you precharge before you turn the main switch/relais on?


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## RIPPERTON (Jan 26, 2010)

A heavily resisted circuit has very little amperage flow so you dont get any arcing at the contacts inside the switch so you dont need a relay.
wait about 15 seconds or just watch your volt meter if you have it connected to the controller side.


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