Solar panels; import tariffs and MC4 connectors

Cutwater28GG

Cutwater28GG

Well-known member
Joined
Jan 14, 2016
Messages
1,996
Location
seattle
Fluid Motion Model
C-28
Non-Fluid Motion Model
Cutwater 28
Vessel Name
Living The Dream
So I think I will install a second panel this year. I am struggling to find the Kyocera panel online - I think something to do with the new tariffs on panels.

any recommendations for a US made panel for marine use in the 140w spec - Does the factor have any advice on what they are installing these days?

I have the sunsaver PWM controller which I will keep (yes I know an MPPT is better but find a reasonably priced 25 amp one is not easy. nor do I fancy doing a new install)

I'm not at the boat at the moment, does anyone know if the standard panel has MC4 connectors that I can just add a parallel connector to such as https://www.solar-electric.com/mumc4colam.html or is the wiring more complicated than that and I have to open up the roof/cable runs?
 
I installed a second panel on my boat earlier this season. I was able to get one of the last 160w Kyocera panels at the time. Kyocera has stopped making that panel which is why its near impossible to find in individual panels. The factory has switched to a panel that has silver aluminum. I installed this panel on a friends cutwater at the end of this season -

https://www.solar-electric.com/solarlan ... panel.html

You will still be within the limits of the Sunsaver Duo with the 140w panel and the 160w panel. The panel that comes with the boat has a junction box which is hardwired directly to the charge controller. I used 10 gauge wire with blades at the junction box in parallel (+ to +, - to -), and crimped mc4 connectors on the exterior end to connect the new panel. I then ziptied them to the rails under the panel to keep them out of the weather. On a sunny day I make up to 22amps, on a cloudy day 3-5amps. More than enough to keep the fridge and other odds and ends going on the hook without needing to run the generator.

Hope that helps!
 
thanks Admiral! super useful!

Is your junction box on the roof or do I have to run these new wires through the roof to the junction box below?

for the Cutwater install - I assume you installed them side by side? so had to move the first panel further over to the edge of the roof?
 
The Junction box is part of the existing Kyocera panel you have. Its the black box on the underside of the panel. You loosen the 4 corner screws and the door swings down giving access to the terminal box. You will probably have to undo the existing panel to get access as that is what I had to do on the Cutwater 30S. I highly recommend covering the panel with a thick blanket or towel to block any power generation. You will not need to drill any new holes as all connections are made externally through the panels. You will need another set of SeaDog mounts for the new panel. And you will need to carefully drill new holes in the aluminum sides of the new panel to align with the racks.

https://www.fisheriessupply.com/sea-dog ... d-327190-1

The existing panel will need to be slid over, and on a Cutwater 30S it was interesting because it covers the overhead windows quite a bit.
 
genius! thanks so much! this makes the install pretty easy! (famous last words!)
 
It wasn't that bad. A lot of crawling on my back on top of the pilot house on our R-27. I also was freaking out that I wasn't seeing enough power at 4pm, so ensure you look at the output with roughly the same conditions, boat placement, and time of day before and after. You should see your output almost double afterwords.
 
You know, if my memory serves me correctly just switching out the controller to an MPPT will increase the charge to the batteries considerably. I guess a little research will determine if it is worth putting in another panel or just switch out the controller.
 
knotflying":qugtfwt5 said:
You know, if my memory serves me correctly just switching out the controller to an MPPT will increase the charge to the batteries considerably. I guess a little research will determine if it is worth putting in another panel or just switch out the controller.
Click to expand...

A few items to note when considering switching to a MPPT controller:

1) I have not found one that will charge 2 batteries like the Sunsaver Duo. Probably not a big issue since there shouldn’t be much draw on the start battery when at anchor. Charging only the house is probably fine as long as the boat is not left for long periods without a charge source

2) The efficiency gain varies widely with setup (panels used, wire run length, etc.) and panel temperature. MPPT has greater benefit at lower temperatures due to panel voltage which increases as the temperture goes down. If you boat in the winter in colder climates it may be worth the switch.

3) At best you are looking at about a 30% improvement on average at lower temperatures. It certainly will not equal the gain from an additional panel.

4) The cost to buy an MPPT controller is higher. About $300 for a 25 amp controller.

I have not switched because our PWM controller appears to meet our needs with two panels. If I needed to switch out the PWM controller for other reasons or were setting up a system from scratch I would consider buying an MPPT controller.
 
Good info. I did see that you can only use one bank, which in reality is insignificant. I have mine set at 90 % house 10% engine. 10% going to the engine probably isn't required.
 
thats the conclusion I came to Red; the cost/performance benefit of an extra panel over a new MPPT controller that would also require some extra installation headaches made choosing adding a second panel the better choice.
 
You guys seem to be fairly knowledgable about solar panels and I am not. I have some questions; I have a yakima box mounted next to my solar panel on my C28. I'm wondering if I could mount a roll up panel on the top of the box? I saw a 60w panel for $6-700. I also saw a 30w "flexible" panel for $60 on Amazon. Could I mount a couple of those and connect to the original panel as you described?
 
i am not an expert but I cant see why an advertised "12V" solar panel connected in parallel wouldnt work mounted on the roof box. get the largest wattage panel that will fit.

power (watts) = volts x amps. Therefore as 12volts is fixed the higher wattage panels will produce more amps.
 
The flexible panels will add additional current but may lower the charge voltage so you need to check the specs. Not all 12V panels are the same. 12 volt panels typically produce up to 17 volts or so. A parallel connection is limited by the lowest voltage of the system. To charge the batteries you typically need significantly more than 12 volts. If the flex panel is producing 16 volts while the fixed panel is producing 17 volts you will only get 16 volts for each. The power of the fixed panel (P = V x I) will be reduced (limited by the lower voltage panel connected in parallel) and thus the total power between the two panels needs to consider this.

If the voltage of each panel is similar at the same temperture range then you should be fine. Then the power for each panel can be added to estimate the total power of the system. Also be sure to stay below the total current spec for your controller.
 
interesting. is this because of a unique trait in solar panels or general electrical science?
 
A little of both. Solar panels act very much like a battery. If you connect a lower voltage battery in parallel with another of higher voltage the voltage of the higher battery will be limited by the lower voltage battery.

Here is a link that explains it better than I.

http://solarpanelsvenue.com/mixing-solar-panels/

BTW. Voltage matching is also the reason MPPT controllers are more efficient than a PWM controller. In this case the match is between the panel and the battery. An MPPT controller uses a DC-DC converter to convert the solar panel voltage (which otherwise would be limited by the battery voltage when using a PWM controller) to match the optimum battery charge voltage. The excess voltage results in added charge current instead of being lost as with a PWM controller.
 
Great link Red Raven!

Now I need to understand the voltage of my panel circa 2012 from the factory and which are similar speced from a voltage perspective now its not possible to buy the kyocera.
 
Bringing back an old thread as I am now looking to add a second panel. Like others I have not been able to locate a 145 watt Kyocera panel and all of these links are showing no longer available. By chance has anyone has found another source as it would certainly be easier (and cheaper) to just add one rather than replace with two new ones? Marine electrical is not my strong suit and from what I gather there doesn’t seem to be much benefit to adding/replacing the controller for my purposes. We trailer a lot and hoping this will keep everything adequately charged while going down. I have run my Honda generator in the cockpit to keep up with the refrigerator and other things but looking for an alternative.

Thanks!
 
You can always go a bit larger or with a different brand. You just have to make sure that your controller has the capacity to handle the charge from the panels.
 
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