[jboncek]

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.

[tomofreno]

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

[jboncek]

Originally Posted by tomofreno

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....

[honn1002]

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.

[jboncek]

Originally Posted by honn1002

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.

[gottdi]

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

[engineer_Bill]

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.

[jboncek]

Originally Posted by engineer_Bill

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?

[gottdi]

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.

[jboncek]

Originally Posted by gottdi

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.