MidNite KID Marine MPPT

[CruisingCouple]

I tested the KID Marine MPPT controller with two 36Vmp 160W panels in series and parallel, and pretty pleased with it. It handles partial shading very good, with the power output of the panel string reduced approximately 140% in proportion to the shaded percentage in series. Rewiring the two panels in parallel yielded better partial shading performance, however, with power output reduced almost in a direct proportion to shaded area.

It uses a fast timed I-V sweep algorithm to find Vmp and it reacts very fast in my testing, within a few milliseconds to changes in system load and PV output. Idle power consumption is less than 1 watt.

It has pre-programmed charge profiles for flooded, AGM, etc., plus no-float profile for lithium batteries. The charge stage set points and times are adjustable. The controller comes with a BTS. With the optional shunt it will exit absorb stage based on net current to the battery, independent of the timer.

This is a beta controller so it doesn't have all the production features yet, which will be released in future firmware updates. But overall its performance is very much on par with its bigger brother, the MidNite Classic. Although the KID is 30 amp output on 12V system, where the Classic is 96 amp.

[jseas]

Thanks! This was news to me.

[CruisingCouple]

Sorry that I forgot to mention that the KID Marine is a new product from MidNite Solar. It has conformal coated boards, is fully enclosed and unvented to keep bugs and water and dust out, and is heat sink cooled with no cooling fan. It is a higher end controller based on their proven Classic series and costs in the $400-500 price range.

The one I have is a beta version, but the only thing that is beta in it is the firmware. There is nothing beta in the solar control functions, however. The production version is slated to have more features for wind and hydro turbines.

[noelex 77]

Thanks for the report.
Midnite make great solar regulators and there is a shortage of good controllers at this size.

The Rogue has always been the best, but they have been very slow to release their new model. It will be interesting to see the independent measurements of tracking efficiency etc between these two controllers. I suspect they will both be very good.

[CruisingCouple]

Originally Posted by noelex 77

It will be interesting to see the independent measurements of tracking efficiency etc between these two controllers. I suspect they will both be very good.

I think they both use the fast timed I-V sweep method of tracking Vmp. Whereas most of the cheaper controllers use dynamic tracking, which is much slower. The fast timed I-V sweep will find the global maximum with a partially shaded array. Dynamic tracking does not react fast enough for sailing yachts due to shading from the sails at times, and the boat pitching and rolling causing uneven and unequal solar insolation at the panels when underway.

The cheaper dynamic tracking controllers should work fine, though, when dangling on the hook where they don't have to react to changes real fast.

We are not going to waste our time with wind turbine on our boat. I would add another solar panel or buy a towed water turbine before I will put a wind turbine on.

[Maine Sail]

I am on the beta test list but don't have it yet. Can't wait to test it out... They should be shipping mid to late first quarter..

[CruisingCouple]

It will be interesting to hear your thoughts on it after you get a chance to test one. I don't how the KID really compares to the Rogue MPT-3048. I haven't seen the street price on the KID yet but I think the marine version will probably be a bit more expensive than the Rogue.

Personally I don't like the heat sink arrangement on the Rogue because it's back against the wall. The KID Marine comes with a mounting bracket and the heat sink in the front for good cooling and air circulation around it. Electronics and heat don't get along good and the cooler you can keep the critical components like FET's and transformer the longer the unit will last and the more trouble free it will be.

But that's probably nitpicking because few cruisers run big enough solar arrays on their boats to push the controller to the max anyway. And the folks that do have bigger arrays usually use multiple controllers.

[4arch]

A year later - any updates?

I was going to buy a Rogue but it's been showing as "Temporarily Out of Stock" for about a month now on their website. Would I be just as well off with the KID?

If I do go for the KID, is it really worth paying more for the "marine" version? It comes with a battery temp sensor, a yoke style mounting bracket (as opposed to a frame for surface mounting for the non-marine version), and supposedly additional conformal coating on the PCB. I can get the non-marine for about $60 bucks cheaper and add the battery temp sensor for $20. I don't see why a yoke mount is inherently more marine-friendly and I would prefer to surface mount it to a bulkhead. As for the conformal coating, I am going to mount the controller in an area not subjected to unusual moisture.