Optimistic Kelly

Joined
May 25, 2012
Messages
54
Location
milky way
Trilska said:
The Ca mesures battery current while the kellycontrolers are defined via pfase current.


Thanks Trilska, but what does "pfase" mean? is there a way to calculate Pfase current from battery current?



thanks
 
Ops i mispelled it. phase current.

Phase current is the actual current that the motor "feels" ( ie gains torque from), and i have not come across any good method on how to calculate it properly, but as a rule of thumb the phase current will be 1.5-3 times higher than battery current. This is of course depending on the motor itselfe and other parameters. I am at my knowlage limit but i am sure further info is somwhere around the forum, so you just have to practise your endless/google-fu. 8)
 
That situation of not reaching max power can also occur when the LVC is set too high or when your battery voltage sag too much and the LVC trip and lower the current to avoid overdischarge.

Doc
 
Is your CA limiting the amps??
 
Trilska said:
Ops i mispelled it. phase current.

Phase current is the actual current that the motor "feels" ( ie gains torque from), and i have not come across any good method on how to calculate it properly, but as a rule of thumb the phase current will be 1.5-3 times higher than battery current. This is of course depending on the motor itselfe and other parameters. I am at my knowlage limit but i am sure further info is somwhere around the forum, so you just have to practise your endless/google-fu. 8)

Thanks again Trilska. I've done some reading and apparently the phase current is 1.732 X Line current (in one of the methods), which indeed takes the 30A line current to 50A phase current. However, it's like saying that I'm wearing an 88 size shoes (summing both feet) - a slight twist of the truth :cry: .
 
Doctorbass said:
That situation of not reaching max power can also occur when the LVC is set too high or when your battery voltage sag too much and the LVC trip and lower the current to avoid overdischarge.

Doc


Hey Doc,
When you say LVC, you probably refer to the CA function which I'm not using. The only functioning LVC in my setup is the physical boards I bought from "Methods" and these are fixed per cell.
It is for sure not a case of too much voltage sag - I've done the test when all the cells were hot of the charger - 4.2V per cell.

Thanks
 
space4dreamz said:
Doctorbass said:
That situation of not reaching max power can also occur when the LVC is set too high or when your battery voltage sag too much and the LVC trip and lower the current to avoid overdischarge.

Doc


Hey Doc,
When you say LVC, you probably refer to the CA function which I'm not using. The only functioning LVC in my setup is the physical boards I bought from "Methods" and these are fixed per cell.
It is for sure not a case of too much voltage sag - I've done the test when all the cells were hot of the charger - 4.2V per cell.

Thanks


The LVC i'm reffering to is the one that your controller is set to... ex: LVC is 36V for 12s lipo...

Doc
 
Doctorbass said:
The LVC i'm reffering to is the one that your controller is set to... ex: LVC is 36V for 12s lipo...

Doc


OK, got you now. But like I wrote - The battery is "hot of the charger" and its way far from the controller LVC limit, it's around 47.5V (under load).
I dont think it's a case of cut off at all cause I'm not feeling any "cut" on the throttle.
It's probably just a case of marketing high numbers as opposed to real life numbers (phase current opposed to line current).

Thanks again Doc.
 
I too had heard or read that Kelly amps are phase and not battery which would mean your system is working as intended. If you want more I have always found the 72v 40a controller Justin sells at Grin is ideal for the HS/T 35xx series motors allowing them to produce 3kw.
 
space4dreamz said:
It's probably just a case of marketing high numbers as opposed to real life numbers (phase current opposed to line current).

I've used 10+ brushed and brushless Kelly controllers on vehicles ranging from ebikes to a VW Bus conversion (build links in signature); Kelly always rate their controllers as motor amps instead of battery amps, and quote the "10-second "current instead of continuous current, so many people have been surprised as you have been.

I think rating by peak motor current more common in the brushed-DC automotive world where Kelly started, but it is very confusing to those of us who come from the ebike world where BLDC controllers are rated in continious battery amps. OTOH they did build solid controllers when choices were limited, but controller choices have grown exponentially, so...

-JD
 
Tench said:
I too had heard or read that Kelly amps are phase and not battery.


oatnet said:
I've used 10+ brushed and brushless Kelly controllers on vehicles ranging from ebikes to a VW Bus conversion (build links in signature); Kelly always rate their controllers as motor amps instead of phase amps, and quote the "10-second "current instead of continuous current, so many people have been surprised as you have been.


Thank you all for the insight & the enlightment.


No thanks Kelly for selling an over priced controller with nice numbers (on the brochure).


That mini controller is my first Kelly, and mos-def my last.



Space4
 
went from blowing highly modified 12 and 18fet Infineons that promised world
performance wise, to a Kelly controller.......

night and day difference, throttle control on the Kelly is amazingly good
power deliver smooth and constant..

Will Never go back to cheap infineons for "rc motor" application...

KiM
 
So you are blaming Kelly because you can´t read? :roll:


After I blew a modified Infineon for no apparent reason, and decided to buy a Kelly instead, life has never been easier.
I´m never going back to the Infineon style controllers.
Kelly even comes with warranty...

Not to mention the LED signaling faults, has saved me at least a few hours on trouble shooting...
 
thanks for the info give here. How can we determine max battery current from their specs?

The KBS72121L is rated 50A phase, it seems it does 30A battery current. That is 3/5. Is it always 3/5? So a 200A rated Kelly automatically does 120A bat current?

EDIT: They tell that
•Max Battery Current: Configurable.
How? Is there i thread about this somewhere? I want battery current close to phase current since i like the "ICE like feeling". It helps to reduce Wh/mile and always forces me to shift the best gear .

EDIT2: found this page about Kelly programming: http://bergerweb.net/electricbike/programming.shtml
 
From the KBS Manual:
(7)Max Battery Current
Value range: 20%-100%
[...] Factory default is 100%.
This is not so good :( Seems like 30A is the max your controller will do :oops:

Edit: Ok, the larger KBL72101X like http://kellycontroller.com/kbl72101x24-72v100abldc-controllerwith-regen-p-56.html
are no option, it can doa about the same as the MUCH smaller KBS72121X http://kellycontroller.com/kbs72121x55a24-72v-mini-brushless-dc-controller-p-529.html

BUT: it cost almost $90 more !!?! That must be a joke :lol:
 
I have always suspected the kelly controllers were spec' ed by phase current and I think this is one of the reasons why some people say they tend to be more reliable and due to the low current and the slow ramp up of the throttle it appears that the overall throttle control is much better.. when if the same setting were incorporated into a 12fet or 18fet controller it will feel nearly the same but more responsive ( no lag in throttle ) , I have not ever tested a kelly but people that I have talked to and worked with have all been disappointed with the lack of snappiness of the throttle response when they are after a bigger hit by so called upgrading the controller.
 
gwhy: Throttle LAG!?!? In a $$$ controller!?! Is this a joke as well? I must test this!

From: http://endless-sphere.com/forums/viewtopic.php?f=28&t=57668&p=874709#p874679

dan974 said:
crossbreak said:
about our Kelly: It seems that it does only around 3/5 as battery current of the rated 55A "motor current". That would be 33A battery current for our chosen one. For 20s Li-ion we should see 2442W peak. Not 4kW :oops: this motor will be bored a bit: http://endless-sphere.com/forums/viewtopic.php?f=30&t=57596&p=874677#p858870
130 peak should give you 0.7 x130 =90a peak, and able to give 40A continuous.... My 240 rated peak key gave me 189A ( battery) in thé sand, and easy 110 A boost on flat the question is : are you able to handle a 72V 90a peak ? Don't forget the kelly is a square/truesin mix,... I think the guy you mention was never able to setup it....but I do not know kbs only key ones....
http://kellycontroller.com/faqs.php
http://kellycontroller.com/KBShelp.php

Set motor at 100% if you don t care heating it
And battery % according to the peak value and the I precomize 60% OF YOUR battery C discharge not to destroy it...for exemple a 8ah 30c = 240 A take 144A as max discharge not to damage...so set at 100% battery (or maybe 70% is max like on keb model) If you got a 20c 8ah, 160 À discharge, take 96A AS REAL, THEN downgrade the battery current to 70 % to protect from too much discharge, or if your sag is too much
Take nite that the software can give you full motor current at low speed because of current multiplication....so it could be your battery pack discharge rate that limit, if you haveore Amp, you reduce the sag and so you get a higher Discharge C
Kelly recommend to get 2 to 3 time the power motor rated.....72V*55A =4kW rated should be ok for a 1500/2000w rated motor....
Correct me if I m wrong...ask gindc why is truesin is more powerfull and faster with less amp
 
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