• Have you tried out dark mode?! Scroll to the bottom of any page to find a sun or moon icon to turn dark mode on or off!

diy solar

diy solar

Switch panel for solar?

jdege

New Member
Joined
Dec 16, 2020
Messages
183
I'm fitting out a sailboat as a liveaboard. This will include as much solar as I can fit.

I'm trying to design the solar wiring harness. And I want wiring I won't have to redo from scratch every time I make a change. I don't expect that my first arrangement of solar panels will be my last, or that the set of MPPT controllers I buy when I start will be all I ever buy.

So what I'm thinking for wiring is to position solar cable entry gland housings at various points on the boat:

51UPNbKGZ5L._AC_SL1000_.jpg

Then to run cable from there to a centrol location, where I'll have disconnect switch on every cable, the other end of which will run to the various MPPTs.

I'm also considering some sort of patch panel so I can choose which solar panels to to which MPPT controller.

There will be at least three MPPTs, because I have three separate banks - 2 ea. 48V systems for propulsion, one for each of the electric motors, and 1 ea. 12V system for house loads.

There will be six or eight sets of solar cables running into this. At least three MPPTs possibly powered from it.

Anyone have ideas about available hardware that would make this work?
 
You should draw out a schematic of what you want to do. Add in provisions for future upgrades. I'm assuming it is a cat because of the 2 motors. What year/make/model?
I would try and keep it simple. Every connection and switch is a potential failure point. Just directly wire every (through fuses/CB's) and leave service loops in the wire. Leave blanks in the panel for future circuits and charging sources. If things are thought out up front, I see no need for a "patch panel" to swap around panels and SCC. Based on layout, you will wind up with varies series and parallel strings. Then you match a specific SCC for that string.
You will need to reach the required voltage for the 48v banks. This will require at least 2 panels in series, then shading becomes a problem.
I would optimize all the solar to charge the 48v banks and then run DC-DC to a 12 house bank. Living on a boat you spend a lot of time on the hook. You waste the opportunity to generate power if the systems are separate and your propulsion bank is full.
 
If things are thought out up front, I see no need for a "patch panel" to swap around panels and SCC.
I can envision very different charging profiles depending upon use patterns that might change week to week.

If I'm in the islands on hook doing nothing but lying around in the sun and watching Netflix, the propulsion batteries will be at full, and having no meaningful draw. And they'll need no charging.

If, on the other hand, I'm motoring up a river I'll be pulling a lot from the propulsion batteries, and I'll want all the power going into them that I can manage.
 
That's why I recommended putting all the solar into the propulsion batteries and charging the house bank from there. You can decide if/when/what pack to draw from simply by turning on/off a pair of DC-DC chargers.
 
That's why I recommended putting all the solar into the propulsion batteries and charging the house bank from there. You can decide if/when/what pack to draw from simply by turning on/off a pair of DC-DC chargers.
It's a thought.

I'll be bench testing some of these ideas this winter.

I've heard it said that Victron's MPPT controllers make fire better DC-DC chargers that their DC-DC chargers...
 

diy solar

diy solar
Back
Top