Another Solar Panel Question. . .

[Sail22Capri22]

I cannot seem to wrap my head around what solar setup would work best for me. I would like to put a 50w Renogy flexible solar panel possibly on my companionway hatch on my Capri 22. This will be to charge a single 92ah AGM battery. I calculated that my power consumption will be around 4 amps for only a few hours a week during the summer. This power consumption comes from navigation and cabin lights used, no other type of draw. Will the 50w panel be enough to keep the battery topped off? Also which charge controller should I use. Wondering if the wander 10a PWM controller would work fine?

 

[dlochner]

As a rule of thumb Solar panels can produce about 3 times the nominal capacity per day. So, a 50w panel will on average produce 150wh or about 12ah per day. More the further south you are and the sunny it is, less further north and cloudy.

An MMPT controller is more efficient. The Victron Controllers with Blue Tooth are efficient, easy to program, and reliable.

 

[Stu Jackson]

I calculated that my power consumption will be around 4 amps for only a few hours a week

You need to be careful about the terms. 4 amps for 3 hours a day is 12 ah, or amp hours. Which is different than 4A or 4 ah, as you can see.
In any event, once you've straightened out your consumption in amp hours then you figure out how much is going back in, in ah, which Dave has helpfully provided.

about 12ah per day

It appears your 50W panel will be just fine because it will return in one day what you take out in one day. All the rest of the time it's just sitting there keeping your bank topped off. If you only use your boat a couple of times a week, you could even get a smaller panel.
Good deal.
While MPPT controllers can get a bit more out of panels, you might want to determine for yourself whether there is a cost benefit ratio to you, based on your use and the difference in cost of the controllers.

 

[Project_Mayhem]

Get a decent charge controller such as Victron or Morning Star. If I had a choice between MPPT and a PWM unit from a reputable brand, I'd pick the reputable brand. It ensures that your batteries don't die prematurely and that it wont catch on fire like some of the Chinese units (including Renogy). Here's some excellent articles regarding solar Solar & Renewable Energy Archives - Marine How To

I've had a 100w Renogy panel with a couple of used, lower end Morning Star controllers for about three years now. I haven't had a low battery since I installed it. It is usually easier to isntall a couple of smaller panels than one big one