Adding 350w solar panels to cockpit roof

Status
Not open for further replies.

Happy Place

Well-known member
Joined
Mar 16, 2021
Messages
96
Fluid Motion Model
C-302 SC
Vessel Name
Happy Place
Our 2014 R31 CB will be on a mooring ball and we want to be certain that all banks are kept topped up and we have enough solar for 48 hours offgrid. We've used the spreadsheet and it looks like 2 175w panels will suffice up here in Boston.

My question is.....where on the boat can we pull the wires down from the hardtop to the controller?

And....will the stock charge controller handle 350watts or should we upgrade?
 
I'm fairly certain the stock solar controller is insufficient to handle 350 watts. Plus, being two panels, I'm assuming you'll be hooking them up in series, which doubles the voltage as well. So the controller not only has to be able to handle the wattage it needs to handle the higher voltage as well. There are two types of controllers, PWM and MPPT. Generally speaking, PWM is better for smaller wattage panels, while MPPT controllers are better for larger wattage panels. The factory solar controller is a PWM controller.

We are in process of upgrading our solar panel as well. We already replaced the factory solar controller with a Victron Solar Controller, MPPT 100/30. It'll handle up to 100 volts on the panel side, and up to 30 amps at 12v on the battery side. We're going to install a pair of 200 watt panels in series. That'll put us around 80 volts (the panels are 24volts each) as open circuit voltage, and I'll restrict the 12v to the battery to 24 amps in the controller.
 
If you’re going to put two of the older tech 175 watt panel you might as well use the newer 200 watt panels that are only fractionally larger. Newpowa makes a highly rated 200 watt panel for under $190 each at Amazon. Those plus a new Victron Energy SmartSolar MPPT controller, properly sized (100/30 ?) and you’re almost done. Check all your wiring and fuses for the right gauges and correct amperage respectively and correct if necessary.
PS: Assuming you already have a battery monitor. If not I’d definitely add one. And a battery temp monitor to “talk” to the MPPT controller like this one:
Victron Energy Smart Battery Sense Long Range (up to 10m) https://www.amazon.com/dp/B07RTYGMBD/re ... PGEG6ZD9N0
 
If you use the stock Sunsaver Duo PWM controller the panels must be 12volt panels and must be connected in parallel. The limitation would likely be the maximum current from the panels (2x the max current rating of the panel because they will be in parallel). If the total is less than the controller max current rating you’re golden.

If you are installing a new controller then I agree with Martin and Al, go with an MPPT controller and higher voltage panels in series. More efficient.

Curt
 
Consider a single 330W LG panel with the Victon smart controller (100/30) and the 712 smart battery monitor. That is my configuration. The factory wiring my 2011 R29 was sufficient in size which made the install much easier. You will probably get as much power out of the 330W panel with a smaller panel footprint.
 
Search Jeff Cote on YouTube for great info on solar, and electrical marine topics. A true expert on the subject.


Sent from my iPhone using Tapatalk
 
id highly recommend looking at split cell panels that if half is shaded then the performance drop off is less. I had a good experience with the panels available via Platt. Good selection. I ended up with a single 340W panel on the centerline of my cutwater 28. it was only a few inches longer and wider than the exiseting 135W panel the factory users.
This is my panel
https://www.platt.com/platt-electri...PEAK-DUO-BLK-G6-340/product.aspx?zpid=1458239 for $240 and I went the 100/30 Mppt bluetooth controller

also with a 2 panel setup Id recommend two Victron MPPT controllers one for each panel.
i also love the victron kit for their bluetooth connectivity and battery sense modules that can be easily networked to ensure the charging voltage at the batteries is actually correct based on cable losses. https://www.victronenergy.com/

I havent done the math but you'd probably go with two 75/15 MPPT controllers for a 200W panel.
 
I went with a similar setup to Gavin... one Hanwha Q.Peak-G5.2 DUO 325W, 60Cell, Monocrystalline panel; the Victron SmartSolar MPPT 100/30 Solar Charge Controller; and the Victron 712 Energy Battery Monitor. I installed it all myself with some new cabling and Blue Seas circuit breakers last summer. It all makes for a nice package that works well together. I am very happy with the results.
 
Status
Not open for further replies.
Back
Top