MPPT Charge Controller Instal

When we installed the new lithium batteries we were not in a position to replace the existing PWM Solar Charge Controller which is a (Legacy) Speciality Concepts Mark 15.  This has worked well over the years to maintain the lead acid batteries.  What I discovered after upgrading to SOK lithium Batteries (read about the instal here) is the PWM just will not fully charge the Lithium Batteries.  So it’s time to update the solar charge controller before the 2021 Boondocking season begins..

While there are several great 30amp MPPT controllers out there (Victron, Renogy etc.) none have the ability to act as a direct replacement – i.e., flush mount to fill the hole in the aluminium wall!  However, after some extensive research I have found a replacement MPPT controller.  I will be installing a Blue Sky 3000i to replace this Speciality Concepts PWM legacy controller.

Did I mention that the exchange should have been a simple – “Plug & Play”?  Yep – remove the old PWM and instal the replacement MPPT – simple, right?  Well when I pulled the existing PWM controller this is what I discovered – – #@%&* 🤬 nightmare scenario (see pic)

Who would have thought that there would be every wire known to humankind directly behind the existing PWM controller? Not only the main 12v bundle, there happens to be the wiring for the 110v system. Give me a break Airstream what on earth were you thinking? (I guess they don’t plan for the future).  The PWM controller fit because it’s only 3/4″ deep while the new MPPT controller is 2″ *#@%& deep and would require the full unobstructed depth.

Yep, hindsight is simple. I can hear it now from all the smart people in the peanut gallery – “if I was you, I would have remove the old one before I bought the new”.  Well I didn’t, as this should have been a simple “plug & play”.

What this mean is that I am now faced with several challenges.

  1. Cover/Patch the hole and find a new place to instal the Blue Sky Controller. or
  2. Eat the $350 bucks I have paid for the Blue Sky Controller and obtain a Victron Smart Solar MPPT 150/35 150V 35A for an additional $450.00.
  3. Because I can’t use the existing wiring I must now run new wires from the existing solar panels (fortunately the wire lead drop down behind the Refrigerator), also need to run new power wires from the 12v control centre.

The Instal – love it or hate it – it’s clean and it works!

The Cover/Patch – this is the easiest part.  Went to a local Aluminium Trailer Manufacture in town and had a thin (1/16 x 4.1/2 x 6.1/2) piece of aluminium cut for me.  Drilled the four corners and riveted over the hole.  Simple, clean, easy and once polished it will look just fine. (PS. the existing remaining solar charger wires are dead – just saying)

The Wiring – Solar panels are wired with 10 gauge from the roof via the Refrigerator Chimney Vent.  Spliced into with new 10 gauge, drilled through the wall behind the Dinette Bench, then into the existing wire chase to the new location for the Blue Sky Charge Controller. Once the Dinette Bench is reinstalled the wiring is completely hidden. The power wiring is located in the battery compartment which is located under the Lounge (see the Lithium Battery Instal) and done.

The MPPT Controller Instal – Since I am not about to spend an additional $450.00 I located the Blue Sky controller in the ONLY possible available location … the arm of the Lounge, Yep, that’s right.  It worked out just as fine as frogs hair. 😎

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