Author Topic: Correct KID Midnite 150 Controller  (Read 564 times)


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Correct KID Midnite 150 Controller
« on: March 02, 2021, 02:00:59 AM »
I am new to this forum - I hope I have posted this correctly , my apologies if not .
On my sailing yacht , I am building a propellor / shaft  driven charging system , for use when under sail . The free wheeling propshaft will drive a small PMA Alternator , with a maximum output of about 15 amps . I wanted a KID Midnite 150  - 30 amp   WIND - HYDRO - Solar  Charge controller . These have been discontinued , so I was supplied with the SOLAR only version . My question is will this unit work in my PMA Alternator set up . The output should be fairly steady within its range - no wild fluctuations . To add to my problem , I live in South Africa and my boat is in Greece ( I hope it is still there ) . Your help would be greatly appreciated - thanks Garth Gregory


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Re: Correct KID Midnite 150 Controller
« Reply #1 on: March 08, 2021, 10:59:50 AM »
Well, the speed and output voltage would want to be pretty constant. If that is the case, it will work. If not, perhaps Mario could walk you through updating to the wind and hydro model although I believe there was a resistor change for that model?
The reason we discontinued that model was not because of the Kid. It was because of the dump load that was supposed to go with the Kid. After we bought and assembled a bunch of the dump loads, we realized it had a fatal flaw under one condition. I can't remember what exactly it was, but I am pretty sure Mario does. At the moment Mario has his hands very full designing the Hawke's Bay, Barcelona and the B17MPPT module. He will not have much time to devote to this, but I will ask him to work with you as much as is allowed with his schedule. I wish we had more Mario's!!!
Please contact him directly, but do not expect him to be able to spend a lot of time at the moment.
His e-mail (like most of us at MidNite) is his first name and then
We really do like hearing from people on the forum. It is one of the few ways the engineers keep in touch with reality.
Robin Gudgel

mike cunningham

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Re: Correct KID Midnite 150 Controller
« Reply #2 on: March 09, 2021, 01:13:53 PM »

I apologize up front for taking you a bit off topic, but while you wait for a definitive answer from Midnite engineering, I would be very interested in how you established the linkage between the alternator and shaft. Also, the specific alternator you implemented.

I installed a Kid prior to my participation in the SF Singlehanded Transpac in 2016, did the race again in 2018.  The Kid was interfaced to a couple of solar panels and worked very well to keep my engine charging time on the low side.

Prior to the second race I installed a new shaft seal and really did not want the shaft spinning all the way to Kauai, about 2200 NM of sailing. Of course I came to this conclusion when I was about 100 NM offshore during the early part of the race. Consequently I wound up using a stout piece of 3/4 inch birch as sort of a shaft break/lock. What I found amazing was the torque on the shaft when my fixed prop  was freewheeling. I actually saw smoke from the birch stick as I applied leverage to stop the shaft. This got me to thinking that quite a bit of power was being wasted and it might be worth some shaft seal wear to be able to recover some of it.

I could never figure out how I would attach an alternator to the shaft so I would be very interested in how you have done it.