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I blew up ANOTHER controller

Posted: May 02 2019 3:29pm
by Alexanderfoti
So in follow up to this thread: ... 10&t=99506

I killed another KLS 8080I controller.

Same failure mode as the other one, full acceleration around 35 mph. This time I saw around 280amps battery current on the shunt at the time of failure (compared to 350A of the old one!)

KLS14401-8080I - Rated at 400amps peak for 30 seconds and 160A continuous (phase current!!)

The settings on my controller, before it failed were:

65% Motor current
75% Battery current.

Now, this controller is under warranty, so Its being replaced. Internally, a fet shorted closed to one motor winding.......

Fany said to not set the phase current past 65% on the replacement controller, but I feel like that one will blow as well if I leave it at the same current settings.

I feel like I am missing something here. If the motor current setting is the % of the motor controllers rating, then 100% shouldn't break the controller, unless I am pulling more than 160amps (motor current) for hours on end?

I am currently riding around with 50% phase current and 50% batt current setting. I am seeing around 200 amps on the shunt peak, and feel like that is safe enough, but would love some input. Thanks.

Re: I blew up ANOTHER controller

Posted: May 02 2019 4:10pm
by eee291
Wow that's awful! I never had any issues on the small KLS Controllers.
I just bought a KLS 96501 (my first of this size) and I sure am planning to run everything on 100% as I always have.
Now I'm not so sure anymore, sheesh.

Re: I blew up ANOTHER controller

Posted: May 02 2019 4:18pm
by Alexanderfoti
I have the warranty on the replacement controller, but as you can imagine, I am worried about setting anything higher than 50%/50%. Unless I can find a way to accurately measure phase current (3 phases at once) then I can set it to the limit under full acceleration, as full phase current will never be for more than 30 seconds anyway.

I feel I am definitely leaving power on the table unfortunately.

Re: I blew up ANOTHER controller

Posted: May 02 2019 5:18pm
by Ohbse
Root cause is Kelly are rubbish, I feel like we need a sticky at the top of the board with a PSA about their issues. Random detonations are par for the course unfortunately... People luck out and get one that won't explode and post positively about the experience, but unfortunately there are a lot more that experience a string of failures.

I would suggest you look for an alternative controller using some modern technology :)

Re: I blew up ANOTHER controller

Posted: May 02 2019 10:33pm
by Dauntless
There are people here making good money doing that. Damn I miss this thread. ... 25#p686632

Re: I blew up ANOTHER controller

Posted: May 03 2019 5:29am
by Alexanderfoti
Good shout.

Any recomendations on a controller that can do 150v 400amps +?

Alltrax dont have anything that goes up to 150v +
4QD dont have anything either.
The alienpower ones seem ok, but testing shows they failed, and I would have to email for a custom build, as they have nothing past 15KW
Sevcon seems like it requires lots of expensive hardware to configure.

Re: I blew up ANOTHER controller

Posted: May 03 2019 10:57am
by Alexanderfoti
Additionally, I have located:

Curtis 1239E-76xx which may be overkill (120V max - 650A peak (2 mins) 200A cont (60 mins). Looks like it needs a $600 dollar programmer and its also $2900!

Evnetics Soliton Jr. - seems to have vastly ovverated speciications ( Rated Power: 180 KW
Input Voltage 8-342 Volts 600 amps continious with cooling!) at $1800, I have not taken into account the size of each.

My bike already has a cooling loop for the motor so that is not a major issue....

Re: I blew up ANOTHER controller

Posted: May 05 2019 4:33am
by Alexanderfoti
There is of course, another option.

Buy a 1000amp-122v KHB Kelly controller, and run it at 40% capacity. Very unlikely to fail in that application. Big money though, and I must be a gluton for punishment if that's the case :)