# Kelly setting and a question regarding amp's



## riwe (Nov 17, 2011)

Hi all,

My Fiat 500 is almost ready to hit the road and I'm looking for some guidance in programming my Kelly KDC 72601 controller. The Agni 95-R can take about 200amp's cont. @80% of top speed if cooled correctly. The peak amps can be even higher. The 72601 is supposed to be able to deliver 600 Amp's. My batteries can push 10C, 900Amp, for a 10 second period.

I would gladly like some input on these questions:

What size of fuse should I use?

Should I limit the Amps in the controller?

Torque mode, speed mode or mixed – what's your pick?

Also can anybody explain the how motor amp's and the amp's measured "before" the controller are related to each other. 

Best regards

Rikard


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## Yabert (Feb 7, 2010)

riwe said:


> My batteries can push 10C, 900Amp, for a 10 second period.


Well, that is in theoretical territory..... They will probably suffer a lot at 10C.

Now, your questions:

1- 350 or 400A fuse on battery side is enough (search for ANN or CNN 400 (10-20$))
2- Yes. Maybe 400-450A on motor side and monitored the motor temperature after few km.
3- Torque mode.
4- Motor power and battery power are the same (less a bit of loss inside controller). Battery have constant voltage and motor a variable voltage, so if for example the motor need 200A and 36v to develop XX Nm of torque at XXXX rpm, the battery will supply 100A at 72v. Same thing when motor start, if it need 400A and 12v at low rpm, the battery will supply 67A at 72v. 

A great explanation from Evnetics manual: 

*The Basics of PWM Motor Controllers*
Modern PWM motor controllers all work in essentially the same fashion – they chop up
a higher battery voltage into a lower, or at most equal, motor voltage. The basic circuit
used is the switchmode topology called a buck converter. Neglecting conduction and
switching losses (which are typically less than 5% total in a well designed controller),
the behavior of a buck converter can be described with three simple equations:
Vmotor = Vbattery * Duty
Imotor = Ibattery ÷ Duty
Duty = (Ton / (Ton + Toff))
Combining the first two equations shows that output power is the same as the input
power. It is important to point out that motor voltage can never be higher than battery
voltage and that battery current can never be higher than motor current.


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## riwe (Nov 17, 2011)

Yabert said:


> Well, that is in theoretical territory..... They will probably suffer a lot at 10C.
> 
> Now, your questions:
> 
> ...


Hi Yabert,

Thank you for you reply! 

I have a 300 amp fuse installed now and i will order some 400. That way I can test whe, or if the 300 will blow.

Instructions from agni is to keep the motor at high rpm so it can benefit from its natural cooling. Sounds like a temp gauge would be a good investment during testing.

Whats a good 'high temp' value? I guess that depends on were you measure to.

Thank you again

Rikard


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## Yabert (Feb 7, 2010)

From the ANN data sheet, a 300A fuse can take 500A for 10 sec before blowing.

I guess you will never need 30-35 Kw from battery for 10 sec.... if no, you will fly with all this power in a such light car!!.


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## riwe (Nov 17, 2011)

Yabert said:


> From the ANN data sheet, a 300A fuse can take 500A for 10 sec before blowing.
> 
> I guess you will never need 30-35 Kw from battery for 10 sec.... if no, you will fly with all this power in a such light car!!.


Hahahaha! What? And I thought that a 300A fuse would handle 300 and thats it. 

I use ta ANL fues, looks like this one but is rated for 300A. http://www.blekingebilradio.se/PICTURE/8918-14-spd52012.jpg

Where did you fins the ANN/ANL data sheet?

Best regards

Rikard


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## riwe (Nov 17, 2011)

riwe said:


> Hahahaha! What? And I thought that a 300A fuse would handle 300 and thats it.
> 
> I use ta ANL fues, looks like this one but is rated for 300A. http://www.blekingebilradio.se/PICTURE/8918-14-spd52012.jpg
> 
> ...


I found a nice graph here: 
http://www1.cooperbussmann.com/pdf/0810938a-26c4-44e2-a299-8962dd6ea9a7.pdf


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## riwe (Nov 17, 2011)

Hi all,

I made a small video of todays test run. The Kelly is set to 450A and torque mode. Its a rocket!

http://youtu.be/E5nGnoMznTE 

Best regards

Rikard


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