Ideas for removable solar panel for small boat

[Hoosierdoc]

I have a 100W renogy panel I want to add to my Macgregor 26 for next season. I keep it in slip where the stern faces south and would like to mount it to the stern rail. The problem is I’d need to take it down to sail so I need removable connections to the charge controller or battery bank.

I’m hoping for ideas on a Safe method to pass the cables through the fiberglass wall to my under sink battery bank. Would it be best to put the charge controller inside by the bank so it’s protected and get extension wiring from the panel to my interior? I’m hoping for some sort of plug in connector I can mount to pass the power through.

Thanks for advice. Many more questions to follow

[john61ct]

Yes SC should be close to the bank. Not directly above if FLA.

Long run low voltage = thicker wiring

Higher voltage panel = both better efficiency gain from MPPT and thinner wiring.

Anderson PowerPole my standard connector of choice but proprietary marine trolling motor disconnects also good.

[SV DestinyAscen]

If the purpose is to maintain a battery while you're away, given your temporary setup, could consider a simple 12volt DC input with an integral controller?

[john61ct]

If you mean integral to the panel, no IMO.

Temperature compensation is important for a pricey bank.

And voltage drop should be before not after the SC.

There are portable folding blanket style that output 19V for charging laptops, I suppose could be run to a PWM SC at the bank, but that does not seem applicable here.

[Stu Jackson]

I’m hoping for some sort of plug in connector I can mount to pass the power through.

They do make them, but most folks have found the pins to be small and they don't last too long. Like this: https://www.westmarine.com/buy/west-...6?recordNum=29


The other method is to buy a cable clam, like these, where the cable passes through the deck. https://www.westmarine.com/search?Nt...sea+cable+clam


Get a simple plug connector from a short length of wire from the panel to the wiring. Coonnect and disconnect at will.


The controller should be down below, not in the battery compartment, but close to it. Fuse the controller at the battery.


Remember to read the controller manual: usually you disconnect the panel first before ever disconnecting the controller from the battery.

[misfits]

I mounted two 24 volt 100 watt panels on the stern rail using rail clamps. The panels can be folded flat, put horizontal or put below deck in the quarter berth for storage. I used MC4? connectors to make disassembly painless. I just feed the wire up through the ventilation cowls. Hope this helps.

[Stu Jackson]

And this:


Solar Systems: Selection, Installation & Controllers by Maine Sail SUPERB

Installing A Small Marine Solar System Photo Gallery by Compass Marine How To at pbase.com

[jkleins]

Google deutsch connectors. I think they have some heavy duty connectors and may even have a bulkhead mount if I remember correctly. I may have seen that one at Graingers

[john61ct]

Great setup

Originally Posted by misfits

I used MC4? connectors to make disassembly painless.

Sub optimal if frequently dis-/re-connecting.

Andersons are the way to go, or XT-60

[john61ct]

Yes Deutsch good, but lower amps

Ladd https://laddinc.com/products/connector-selector/

Nice thing with standardizing on PowerPole is the three sizes from 14A to 45A are still all interoperable.

And all use the same crimp tool

[rgleason]

https://www.sunwize.com/application-item/solar-modules/

[thinwater]

You will probably get more usable power from a fixed panel that is always generating. Also simpler and lighter. Finally, any panel that is removed and handled will have a reduced life expectancy due to micro-cracking of the cells; even gentle handling is a problem. The full installation was less than an hour... granted, this was not my first solar project.

In this case the wires are fed through turtle, which is a very leak-safe way to do it. This is a Corsair F-24, not very different in size. Only 50W, but more than enough for a small boat with limited systems. I only had 170W on my 34' cruising cat, which had FAR more systems.


There's some small solar stuff on my blog. Just keep it simple.

[Pete7]

Just going back to Hooiserdocs initial question, it might be useful to know why the panel needs to be taken down to go sailing, why not leave it up? after all far less chance of it getting damaged.

He already has a 100w panel which will give about 5A and open circuit 22.5v, rather than a higher voltage panel. He has a Magregor 26 so probably quite a simple battery set up, perhaps one or two Gp31 batteries. So definitely not a "pricey bank" as some have suggested.

If the panel already has MC4 connectors I would carry on using them for the time being as a simple and cheap method of joining the wiring.

No mention of the controller, but with the price of the small Victron MPPTs coming down, something like this is worth considering. Add the dongle or USB widget and really get hooked into watching those wiggly amps flow but be warned its a slippery slope.

https://www.amazon.co.uk/Victron-Sma...r+mppt+75%2F10

My Victron with a 150w panel nearly finished topping up the bank.

[Steven UK]

What Pete7 said... Amoungst other things I have a small solar boat that has three g31 and a 50w panel. Two g31 on the boat and one on land connected to the panel with a Victron controller with dongal. I have a larger trolling motor and the boat will go for hours and has never been unavailable due to lack of charge. The Bluetooth app on the smart phone is addictive, can’t wait to upsize it for the real boat...

The main point is that this system is bullet proof and just works. The batteries will even survive a MN winter because they are kept charged... the trolling motor not so much.

P.s. the Victron customer service is first classs!

[carlheintz]

100 w to keep one or two batteries trickle charged? Seems way overkill. I have a 10 watt small unit I hang on the railing, run the wire under the slats in the hatch, and connect with battery clips to the batteries when I leave... keeps everything totally charged.

You better have a good regulator on that solar bank, because at 100 watts, you will probably cook those batteries by overcharging them. That can lead to all sorts of things you don't want, like boiling battery acid releasing hydrogen gas which can explode with a small spark.

My suggestion is to keep it real simple. It takes me 5 minutes to hang the 10" x 15" solar panel using some aluminum hooks, then run the wire through the hatch to the batteries and hook 'em up.