Solar panel on Cutwater 28

[Cutwater28GG]

Thanks Curt.

I'd guess up here in the PNW the MPPT could give up to 30% improvement over a PWM controller.

The biggest issue I see with the Victron is the space required to mount it. Im not sure it would fit in the current location of the sunsaver. plus those heat fins would likely put off some heat that would need to escape from the closed box current location on the cutwater behind the panel in the mid ship berth.

 

[Red Raven]

Thanks Curt.

I'd guess up here in the PNW the MPPT could give up to 30% improvement over a PWM controller.

The biggest issue I see with the Victron is the space required to mount it. Im not sure it would fit in the current location of the sunsaver. plus those heat fins would likely put off some heat that would need to escape from the closed box current location on the cutwater behind the panel in the mid ship berth.

There are multiple versions of the Victron controller. It looks like the MPPT 100/30 would be the smallest one that will handle two 140W 12V panels in series like the ones on our Tugs. It is still about twice a big as the Sunsaver Duo. It is $226 on Amazon. It is another $78 for the MPPT Controller remote monitor to replace the Morningstar remote panel.

I’m going to see how we do on cloudy days with our current setup. So far so good.

 

[Cutwater28GG]

Yes the 100/30 would be the right model according to my research
but you dont need the remote monitor as the victron has a really good Bluetooth app for your phone.

 

[Red Raven]

Yes the 100/30 would be the right model according to my research
but you dont need the remote monitor as the victron has a really good Bluetooth app for your phone.

Yes, I saw that. I suppose that would be sufficient.

 

[Cutwater28GG]

just in case people are interested and need for future reference. Below is the factory installed panel and its specifications.

https://www.kyocerasolar.com/dealers/product-center/manuals/Manual_KD135-140SX-UFBS.pdf

 

[jkhiser]

The best blog on making solar panels work is:

https://handybobsolar.wordpress.com/

He lives full time off the grid, but many of his findings apply to casual users, like boaters.

A recent post is interesting, implying that manufacturers are reducing the bulk charge recommendation for lead acid batteries, and a recommendation not to go higher than 14.6 volts for absorption.

I followed his guidance when I added solar to my Lance 1575, worked like a charm.

 

[Cutwater28GG]

Thanks but crikey! Quite the forceful rant but he does make some logical points.
I learnt a few things; my takeaways:

1. Short wire runs from controller to batteries with large wire to reduce voltage drop. This is *probably* a problem in our boats having looked at the cable size from the sunsaver. he quotes 6 feet to be way too long between solar controller and battery. - I am going to look at my voltage more closely now at the battery during charging.
2. A charger that holds a high voltage long enough to get batteries to full charge and not turn down to float too early.
3. Good amp and volt meter to get a good sense of loads and current SOC.
4. Get any shadows off the panels. even tiny ones from the radar tower.
5. Check if your solar controller is causing the mains powered charger to turn off early before batteries are full
6. more evidence that cheap golf cart batteries are a good option.
7. Reiterating that flip up panel mounts can make a huge difference
8. He likes the morningstar controllers

for most people who's ranger/cutwater boat use includes being plugged into marinas for most of the time, much of this advice is overkill, but for those who like spending lots of time (multiple days) on the hook.. its worth contemplating.

 

[mikey]

someone posted recently to remind us to make sure your solar panel is securely fastened to the roof rack as a few had the panel fall off in winds when trailering . I found recently when mounting a 360 single panel to a c28 that the mounting tubes are fastened to the lower tubes with a clamp tightened with slot screw. I plan to bolt the upper tube the lower clamp.

 

[mikey]

does anyone know if the solar panel should be disconnected from the batteries over the winter so it doesn't charge from a low of 12.7 volts overnight to a float of 13.4 during the day every day?

 

[scross]

Our R-25C and now our C-28 always had/have the solar system turned on. In the winter in our driveway I have it connected to shore power (to run A/C fans and heaters) and have the solar system on. When not on shore power and in dry storage on the trailer the solar system being on lets us keep the always on systems and the refrigerator running without fear of draining the batteries.
With the solar system on we typically cycle the house bank between 13.5 and 14.5 volts every day. I don’t think that does any harm to the deep cycle house batteries.