# Kelly KDH14**0B vs KDH12**0B



## jboncek (Apr 23, 2009)

Hey there folks,

I'm James, and I this is my first post here, however i've done much reading and appreciated all the detailed info i've found.

I've almost completely narrowed down my choices to a Kelly Controller, yet now i'm rethinking my model, and would like to start a general discussion on the subject:

Originally I was shooting for the KDH14650B, 144V 650A/260A controller.

Now, i'm thinking i'm better off all around, reducing my system voltage to 120V (or less) and using a controller with a higher amp rating such as the KDH12100B 120V 1000A/400A

This came up for 2 reasons really. 1: i'm all for over rating my controller, for saftey's sake and 2: I like the idea of having "higher performance"

Any input is greatly appreciated.


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## tomofreno (Mar 3, 2009)

If you plan to do much freeway driving I would go with higher voltage. Your acceleration at higher vehicle speeds will be considerably better and the lower currents from the battery pack will result in lower Joule losses in conductors/connections. Your acceleration above 45 mph will be pretty anemic with a pack voltage of 108V or below - especially up an on-ramp grade.

Tom


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## jboncek (Apr 23, 2009)

tomofreno said:


> If you plan to do much freeway driving I would go with higher voltage. Your acceleration at higher vehicle speeds will be considerably better and the lower currents from the battery pack will result in lower Joule losses in conductors/connections. Your acceleration above 45 mph will be pretty anemic with a pack voltage of 108V or below - especially up an on-ramp grade.
> 
> Tom



Well, i'm not too concerned with highway speeds as most my travel will be local roads. I like the idea of using less batteries, especially, although the KDH12**B cost more, charging less in series is a plus. 

I also read somewhere on here that the Kelly controller ratings are not exactly true to themselves...Maybe this was another users failure to observe "Boost" ratings, but nonetheless, it is a consideration....


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## honn1002 (Nov 26, 2008)

James, 

If you want to go 120V, get a Curtis controller for better performance and reliability. Model 1231C-86XX series has a wide voltage range from 96V to 144V at 500A. So in the future when you want to go higher voltage from 120V to 144V, you can do it without buying another controller. Just install a good cooling system like heat sink and fans to the controller, it will perform much better.


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## jboncek (Apr 23, 2009)

honn1002 said:


> James,
> 
> If you want to go 120V, get a Curtis controller for better performance and reliability. Model 1231C-86XX series has a wide voltage range from 96V to 144V at 500A. So in the future when you want to go higher voltage from 120V to 144V, you can do it without buying another controller. Just install a good cooling system like heat sink and fans to the controller, it will perform much better.


A major stumbler for me, not choosing the Curtis Controller, is in that it isn't programmable! I would take some comfort knowing that they are widely used and have a good history, but when it comes to all the variable that it takes in/out, I hate to not have any control over it. This could just come from a background of tweaking things and making fine adjustments, but considering that there are alternatives out there that allow for such, I'll take it.

The heating/overheating is also a concern, but i believe this is true for any controller. This is how i really ended up with Kelly as my final choice, really by deduction.


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## Guest (May 9, 2009)

Kelly has revamped their controller line. If the controller says 500 amps it is 500 amps. The early ones did not live up to what was claimed except the low voltage ones. My Kelly is good. It is one of the early SepEx 72 volt 600 amp controllers. It is good.

Pete


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## engineer_Bill (Jun 24, 2008)

I used the 72volt 600amp Kelly also. It works, except that I would have gone with a higher voltage if I had it to do over again. I would go with the higher voltage. Unless the motor is wound for it you will rarely hit the higher currents on street driving anyway.


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## jboncek (Apr 23, 2009)

engineer_Bill said:


> I used the 72volt 600amp Kelly also. It works, except that I would have gone with a higher voltage if I had it to do over again. I would go with the higher voltage. Unless the motor is wound for it you will rarely hit the higher currents on street driving anyway.



Bill: that said, would you recommend the 144V over the 120v Kelly and take the higher voltage over higher amperage?


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## Guest (May 9, 2009)

I'd choose neither because I want both high voltage and high amps. If you can't afford those controllers then I'd choose the voltage over the amps. More than likely you won't be using high amps anyway during normal driving conditions. So yes, voltage is better over super high amps. If Kelly makes 144 and 600 or 700 amp controllers then I'd shoot for that. 

Pete : )

PS. I do not know what Kelly is up to these days in the way of high voltage controllers.


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## jboncek (Apr 23, 2009)

gottdi said:


> I'd choose neither because I want both high voltage and high amps. If you can't afford those controllers then I'd choose the voltage over the amps. More than likely you won't be using high amps anyway during normal driving conditions. So yes, voltage is better over super high amps. If Kelly makes 144 and 600 or 700 amp controllers then I'd shoot for that.
> 
> Pete : )
> 
> PS. I do not know what Kelly is up to these days in the way of high voltage controllers.


Thanks Pete! That almost answers my quandary. That said, i'm looking at and overall decision of exactly where i started:

KDH14650B

For those who haven't looked recently, here is Kelly's table of controllers:

*Model** Boost Current(Amp)** 1 Minute Current(Amp)* *Continuous Current(Amp)* *Voltage(Volt)* * Regen * *Online Order* 
KDH12100B 1000A 900A 400A 24-120V Order 
KDH12101B 1000A 900A 400A 24-120V * Order 
KDH12120B 1200A 1000A 500A 24-120V Order 
KDH12600B 600A 550A 240A 24-120V Order 
KDH12601B 600A 550A 240A  24-120V * Order 
KDH12800B 800A 700A 320A 24-120V Order 
KDH12801B 800A 750A 320A 24-120V * Order 
KDH14400B 400A 350A 160A 24-144V Order 
KDH14401B 400A 350A 160A 24-144V * Order 
KDH14500B 500A 450A 200A 24-144V Order 
KDH14501B 500A 450A 200A 24-144V * Order 
KDH14650B 650A 550A 260A 24-144V Order 
KDH14651B 650A 550A 260A 24-144V * Order

Thanks again for everyone's input. I would love to hear more about user experiences with both Kelly and Curtis Controllers.


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## headrush (Jan 20, 2008)

I was looking at the kelly sites and it looks like the controller will handel regen, and they offer a regen kit. Anyone have any experiences with the regen on a DC motor? Specifically with the Kelly stuff. 

Another quick question, are the Kelly controllers quiet? Or quiet compared to the Curtis?


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## Jozzer (Mar 29, 2009)

The regen is pretty good on the Kelly DC controllers, I use it on most of my motorcycle builds. Usually there is some minor quirk or another, but overall I wouldn't do without it any more.

The Kelly is silent, certainly doesn't screech like the Curtis's I've seen in video's!

I've tried both 120v1200A and 144v650A, the 120v definitly manages to put more power into the 2 Agni motors I use (running in parallel at 90v vs the 144v controller at 144v in series)

I've also run a 72v500A regen model on 1 agnimotor for over a year, 2 100a brushless ones on ebikes, and just ordered in another 120v'er @ 500A.
So far, not a single blowout or RTB, except for a customer who spilt battery acid all over one!

Hope this helps..

Steve


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## Guest (May 12, 2009)

headrush said:


> I was looking at the kelly sites and it looks like the controller will handel regen, and they offer a regen kit. Anyone have any experiences with the regen on a DC motor? Specifically with the Kelly stuff.
> 
> Another quick question, are the Kelly controllers quiet? Or quiet compared to the Curtis?



Kelly Controllers are silent. Period.


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## Hondacrzy (Mar 15, 2008)

I have a KDH12600B And I am pleased with it for the most part. But when I do it again I will go with the 144V system. The power out of the 120V pack when you get down to about 50% DOD is a little weak for me. 

Cheers


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## headrush (Jan 20, 2008)

Well that answers it. I will be going with the Kelly as the price is close enough, and the efficiency is higher than the curtis. Now to find the right batteries, messure and design this thing... oh and getting some moeny together might help.


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## engineer_Bill (Jun 24, 2008)

Good luck with your build. You can always run the 144 at 120volts and see if you like the performance. (And see what the current draw is). You can't run the 120 anything over without smoke. The two controllers you mentioned are both about equally located on either side of the curve. The impedence of your motor makes a difference. If it is a low voltage high current like a forklift motor a lower voltage might work, but the Ev specific motors are make for higher voltages and lower currents. The higher voltage controller will give you the most flexability. My recent experience is that, you do not want your motor to be lugged down sucking down your batteries because you dont have enough power to get up to speed. In that case high current is bad.


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## RoboCoEV (May 8, 2009)

Just jumping into the discussion here...thanks for the great topic. 

jboncek, the Kelly controller you have chosen does not provide regenerative braking. Is this by choice, or because of the savings? Is not the back EMF recharge to the batteries always desireable, if it's available?

This is one thing I like about the Kelly controllers -- you get that option. The Curtis series-wound controllers do not provide regen.

Can anyone comment on regen? Does it work well enough to be worth the extra $?


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## Guest (May 13, 2009)

Do not use regen with a brushed series motor unless you have interpoles. If you have a PermMag motor then you can use regen. Regen works but do not set it to pump too much through the controller. Be careful if you decide to use your brushed series motor. 

Pete


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## jboncek (Apr 23, 2009)

gottdi said:


> Do not use regen with a brushed series motor unless you have interpoles. If you have a PermMag motor then you can use regen. Regen works but do not set it to pump too much through the controller. Be careful if you decide to use your brushed series motor.
> 
> Pete


From what i've heard, this is the best advice, don't do it. But I haven't gotten to do any technical research on the subject. I am using an Impulse 9 series wound motor. I initially choose the non-regen controller as i didn't want to deal with regen, but the more i consider it and discuss it, the more i would like the option, as discouraged as it may be.

My next questions is this: What are the differences in the controller circuit that provide programmable regen? If it is off, will i recieve the same performance? Essentially, should i choose the extra cost, is there any disadvantage of running the controller with regen off?

Can you elaborate of Interpoles? or do you have any sources discussing regen on series wound motors? Kelly specific?

Thanks for everyones input. I have done some searching through the DIY forums, and it appeared to me that this discussion about due, especially with the newer kelly controllers.

Thanks again,
James


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## Guest (May 15, 2009)

jboncek said:


> From what i've heard, this is the best advice, don't do it. But I haven't gotten to do any technical research on the subject. I am using an Impulse 9 series wound motor. I initially choose the non-regen controller as i didn't want to deal with regen, but the more i consider it and discuss it, the more i would like the option, as discouraged as it may be.
> 
> My next questions is this: What are the differences in the controller circuit that provide programmable regen? If it is off, will i recieve the same performance? Essentially, should i choose the extra cost, is there any disadvantage of running the controller with regen off?
> 
> ...


Regen with series motors will put an undue stress on the brushes and commutator unless you have a series motor with interpoles. Interpoles allow you to run your motor at a neutral setting but still keep undue stress off the commutator and brushes. If you decide to do regen with a series you need interpoles and if your motor does not have them then don't do it. The other issue is can the controller handle that regen input back through the controller. In full regen there is lots of power surging back through the controller. Can the controller handle that? I am not sure if anyone here has used regen on a series motor yet. Some regen controllers in the past have not been up to snuff to handle that kind of power. In a forklift with a slow moving vehicle the regen power is minimal and almost any controller can handle that. There is one controller on the market that will for sure handle that regen but that controller is hard to get. I know that the regen controllers that are for SepEx motors work just fine. I am testing my regen function now. 

Pete


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## biscayne (May 15, 2009)

a few days ago the 2nd KDH14500B gave up smoking. At well below 50A!!!
in a 96V system. 
If you read Tesseract`s analyses, and mine, take it for what it is: gladly spend a few bucks on a Controller than to feed the research & developement dept. of kelly- They are cheap but not ready.
It just takes more to take a 200V Mosfet to have a DC motor run on 100V than to just hook the source pins up to it- without a snubber or anything. Its got tzo smoke! Ask me.


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## goglahey (Jul 8, 2009)

Jozzer said:


> I've tried both 120v1200A and 144v650A, the 120v definitly manages to put more power into the 2 Agni motors I use (running in parallel at 90v vs the 144v controller at 144v in series)
> 
> I've also run a 72v500A regen model on 1 agnimotor for over a year, 2 100a brushless ones on ebikes, and just ordered in another 120v'er @ 500A.


Did you max out the two agnies with the 120v 1200amp controller? and if so could it have been done with less (800-1000amp controller) and what was the voltage on them?

Also the Agni X01 had two kdc72601 so maybe two controlleres is better than one? Or maybe it was because off regen??

Regards 

Allan


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## Jozzer (Mar 29, 2009)

Maxxing out short term and long term are 2 different things, this uprated Kelly must be close to instantaneous limit's, but I've not managed yet to test things to the limits over a long haul.
2 controller's may be easier to balance, though i've had no problems so far, and I enjoy the series parallel switch that I can only get with 1 controller.


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## goglahey (Jul 8, 2009)

So the controller heats up and shuts off the power or?

If the long term is 230amps for the agni and 400 peak, the controller shoud be fine right?


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## Jozzer (Mar 29, 2009)

The Kelly is remarkably efficient, not heating much, and being used on such light vehicles (heaviest is a 400KG trike) they don't get full power for very long. No, I think the controller is more than a match for the motors, though the old 1000A (and even the stock 1200A) model never saw a motor pushed above 40 degree's C.

I'm seeing a lot of 750A peaks batteryside with this controller..


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