Solar Panels

[Viper]

Tony, as I'm sure you've read numerous times on here, you have to calculate the charge wire size you need from the charge controller to the batteries or bus bar hooked up to the batteries. The caveat here is that the controller will only accept a small wire size and if you don't want to lose any efficiency you need to go with as big a gauge as practically possible to minimize loss. You're best off to mount the charge controller as close to the panels as possible to minimize the length of small gauge cable used from the panels to the controller. This will minimize voltage drop based on that distance and the wire size in the cable supplied. To minimize the size of the charge wire that you'll hook up to the controller because of their small terminals, install a buss bar next to the controller, then from there to the batteries or your connection/load point you can run what ever size wire you need to run to accommodate full output potential. This will make the system more efficient and safe.

One of the biggest problems with DYI solar charging system kits is that they rarely come with decent sized wiring. They may be fine for an RV but when you have long runs encountered from a hardtop mount in a flybridge application to the engine compartment, the wire size is crucial to maintaining efficiency at that distance and is usually where these kits fall short. The charge controller included with your kit is a good one but I have heard that the biggest complaints are the terminals being too small to accommodate larger wire sizes needed for longer distances. This is typical though of a lot of charge controllers, even the more expensive ones like some Victron models. You just have to keep this in mind when planning your installation if you want to utilize as much output as those panels can provide. Don't fall into the trap of sticking with a certain size charge wire because it's the biggest size that will fit in the controller's terminals. Go with the biggest you can get in there and install it as I mentioned above to get around this problem if the run requires larger wire.

Looks like your kit comes with a the BT-1 module. If you experience any issues with it, contact Renogy and see if they can do anything for you with upgrading to the BT-2 module. I'm pretty sure they made some connectivity upgrades. If you can use the app with no issues then you're golden, otherwise look into the BT-2, they're not expensive in the States.

[tonyiiiafl]

AS I plan to lay out the panels as 2 on port side and 2 starboard with some space in the middle. The wires will be facing the center of the hardtop. I am planning on getting some white vinyl wire chase and stick it down just behind the rearward canvas window. Then send wires to the port side, and on the arch, use the weather proof connector to go in through the side of the arch post. Then chase down the arch to the salon where the A/C vent is and into the bilge. I will mount the controller on the side of the stairs to the aft deck next to my inverter and then it is a short run to the batteries. I will make sure I phot every step. I got this! Lol!

[Viper]

When I install a system, my 3807 has a bench right beside the captain's chair on the bridge. All the wiring from the hardtop and arch routes into that bench and either goes to the helm or down below to the engine compartment. My controller would go in the bench to keep it close to the panels, then I can run what ever size charge wire I need for the distance to the engine compartment. I can also hook up to the main accessory power buss bar under the helm in front of the bench for a shorter distance if I want. That buss bar circuit is wired to handle 100 amps and is already a direct path to a battery switch and battery so really easy routing and install by keeping all the connections up on the bridge. I always thought it'd be cool to see the display on the controller but the app gives you all the information you need anyway, and you can see it from anywhere on the boat so the controller can be hidden if you want a cleaner look.

Looking forward to your pics.

[tonyiiiafl]

I tell you I had this WAY over thunk! When I get the system next week I am going to lay
Out the panels on the floor and see if I can fit 1 or 2 more panels in to make it a 500 or 600 watt system. Since I have a 40 amp co troller it states that it could handle 800 watts of panels. As Trump said about the second stimulus check “GO LARGE!”

[tonyiiiafl]

Also Viper I was also thinking of keeping the controller up on the bridge and using a buss bar as I did with my electronics separate system. I have #6 cable going up there now. I would run the #10 to the buss bar and then continue with the heaviest I could to the batteries. I probably could go to the electronics bar with the controller charge wire and save another run down the wire chase. However I need to research this one out some more or as stated run a new buss bar and 6/0 cable down below.

[tomschauer]

Hey guys, I do not have and have not yet looked into a solar system for the boat.
When you are looking at these, have you checked out the charge controllers? We all have smart chargers on the boats. Do these controllers have the same intelligence so they don't cook the batteries? I would hope so.
As far as bigger is better, again, you would need to look at the operation of the charge controller to see if there is actually any benefit to increased wattage of the panels. If your bank doesn't need more than a 30 amp charger, I would think it doesn't need more than a 30 amp solar setup, and any more would be wasted without having the storage available to meet the panel and controller output.

[tonyiiiafl]

When I have done some research, I do believe that the MPPT type controller is best. They are "smart" in the sense to control charge and also avoid collission of other power sources. Depending on the load used during the day would determine the amount of the system output. I have a 50AMP battery charger and even at that size it takes a couple hours to charge batteries from 75% to 95.

[Midnightsun]

Careful guys, the rated amps for a controller is what the panel puts into the controller not what the controller puts out to the batteries.

IMHO one should get a 40a controller at minimum as you may want to add more panels in the future. I have a 50a unit which controls 4 170w panels. A bank of 2 in parallel and the other bank in series because I have a shade issue with radar and sat dome depending on the sun location at the hard top location. How do you hook up the panels? Series or Parallel? Both have their advantages and disadvantages and will either increase voltage to the controller or amperage. My system will never put out 30a and I could not get by with a 30a controller.

https://www.renogy.com/learn-series-and-parallel/

[tonyiiiafl]

So Midnight, what you are saying is I CAN hook mine up in Parallel (24V) and the controller will (MPPT 40A, 4 100 watt panels) and still use on a 12V battery?

[Midnightsun]

Yes however series will increase voltage and keep amperage to a minimum allowing smaller wires from the panels to the controller. If shading is an issue then you will get more juice from the panels if in parallel or such as in my case a combo of parallel and series.

This explains how shading will render an entire panel inoperative even if the just 1 cell of the panel is shaded. Hooking them up panels in parallel will at least allow the non shaded panels to output their full potential. https://www.pveducation.org/pvcdrom/mod ... ded%20cell.

Most controllers handle 48v +. The controllers job is to regulate voltage and output to the battery bank. There are many units out there but I went with an Epever 50a unit and the bluetooth module which lets me set and monitor the unit through my phone as access to the unit is usually limited and the controls/screens are really crap/small. This guy will accept up to 150v.

Controller, https://www.epsolarpv.com/product/44.html

Blue tooth adapter, https://www.youtube.com/watch?v=ZldaSJlrw-M