Solar Power for Battery Charging

[Christopher]

Fellow Suncaters,
  I am planning ahead for a trip this summer to the Georgian Bay/North Channel and I am going to install a solar panel to keep my battery charged up so I will have Nav. lights, GPS/Chartplotter and cell phone and maybe a Tiller Pilot without the need to recharge my 12V battery at a marina during the trip.  I figure 30 watts would be plenty of power but I'm open to suggestions.  Right now I'm planning on making the solar panel itself portable so I can easily stow it when I don't want to use it.  Has anyone installed solar power for battery charging on their Suncat?  If so would you please provide the forum details on how you did it. 

Thank-you,
Christopher
Second Wind

[rogerschwake]

  I have added just about every thing on my Sun Cat that will fit on board. That includes a 18 Watt solar panel from Coleman that came with a voltage protector or what ever they call them. The panel is about 12" X 36". It fits perfectly on the small aft deck behind the cockpit and between the uprights for the boom gallows. Since I mostly day sail or am gone for gust a couple days don't usually have it on board when sailing. The only problem I can see is getting back on the boat using the boarding ladder, it would be in the way. When I go to the CLR and am using the auto pilot, GPS, radio, charging the phone and using the lights on board with out charging the battery at all. In the summer the boat sets out side with this solar panel connected and sail on average  one day a week. The battery is always at full charge. Hope this was of some help and see you this summer.

ROGER

[ChuckD]

Christopher,
Here's a post I created when I installed mine - which I love.
http://cpyoa.geekworkshosting.com/forum/index.php?topic=9936.msg75011#msg75011

Note: The Amazon link in my post shows Currently Unavailable, but offers similar panels.

Keep us updated!
Chuck

[Christopher]

Great info!

Thank-you

[moonlight]

Sadly, I encounter these assumptions a great deal; and many get angry with me for pointing out the obvious.  But I'm in operations, not sales, so let's go down Reality Way one more time.

Why do you think 30W is ample solar power?  at 12V, that's 2.5A.  At five full hours a day (the standard used for solar chargers), that's net 12.5Ah/day.

What you must know is your consumption!
Nav Lights, LED or Incandescent?  Amps?  Hours per day?
GPS/Chartplotter?  Let's guess.  3A.  8 hours.  = -24Ah.
Tiller Pilot?  FORGET IT, at least in this equation.  Just the chartplotter used twice as much as you'd generate...

And what kind of battery?  Anything with lead in the formula has a 50% depth of discharge; which means your 72Ah Group 24 battery only has 36 usable amp hours.  A 92 Ah Group 27 = 46 useable.  Anything with lead in the formula can only be charged at 10% of it's Ah rate.  Et cetera.

Your trip is feasible.  Enviable.  Desirable.  But do the proper electrical balance calculations, homework, so you have a fun and enjoyable trip.

[Koinonia]

dont get overwhelmed by moonlights post.  If you havnt done this already and you arent using refrigeration pick up a Renogy 50 watt panel with charge controller on ebay for just under 100 dollars and call it a day.  Ive used this on two previous boats and currently have it on top of a pop up camper.  The Renogy panel is well made and havnt had an issue yet.  That being said if you look at my previuos post in the past you can find one where I installed a Kyocera 135 watt panel on a C27 with refrigeration and power was never an issue.  While cruising with cloudy days, watching a movie, multiple fans, anchor light, ect I would be fully charged by 10 am.  In my observations of the GOOD panels is that they overproduce what theyre rated at.  While I was in the Tortugas in July I had a box fan that ran all day in the cabin.  Not just to keep it cool but becuase I could!  Im looking at a Sun Cat and thinking later maybe a Horizon cat.  If I go that rout ill probably just put a 100 watt aft of the gallows on a custom bracket.  Im thinking march or april may be a fine time to head to the Tortugas again from Key west in a HC with a diesel inboard.

[Jim in TC]

To be fair, I would suggest that moonlight and koinonia are both, at least to some extent, right. Moonlight rightly suggests that it is all in the math. When we went off the grid for 20 years, we figured out our potential loads and battery needs as best we could predict and built our solar system accordingly. But there was an extent to which we just went out and bought as much power and storage as made some sense. And as our needs increased we simply added more solar (and ultimately wind) to the system. Koinonia is suggesting that you can almost certainly, in this context, get away with throwing 50 watts at the issue and go sailing. I suspect, based on our experience, that this will work just fine, and maybe even less will do the trick. And if not, adding (or switching to a larger panel) in these days of cheap solar is easy to do.

[Koinonia]

I agree about going less than 50 watts, just from what I have found for sale in recent years the package deal of a 50 watt panel with a charge controller for under 100 dollars seems like the  best bet for the money and for good quality unless you get really low like a 10 watt or a maintainer

[Jim in TC]

what kind of charge controller are you using? It must be a low cost one...has it held up? In our off-grid living we would never buy low on the charge controller, but that was a much different situation. But that experience has made me spring-loaded for going for the best, and that turns out to be pricey. I would like to find something 'good enough' that doesn't cost as much (or more) as the panel...