What are your needs
Well, I know there will be alot of info after I am done so I will start off with a few questions. 1.What are your electrical needs. 2.Are you a live-aboard or a weekender or a day sailor? 3.What is the output of this soar charger? Almost all of the available chargers work. They provide differant amounts of power. A 10 watt solar panel will produce about 850 milliamps or .85 amps. at 12 volts. These panel voltages are directly related to the amount of sun/light. This voltage can be used @ 100% into a devise that is being used.(vhf,auto pilot)It can also be used for charging. Remember that the battery(unless severely discharged) only accepts a percentage of the power that is run through it. If you are a weekend sailor,and your consumption is minimal. say 10 amp hours. If your 10 watt panel is in the sun say 8 hours a day 7 days aweek. 10watts x 8 hours x 7 days =560 watts. 560watts/12volts= 46 amps per week. A 10 watt panel should do fine. At .85amp it will not boil the batteries like a larger one so a regulator/limiter would not be required. If you brew coffee at 10 amps for 2 hours a weekend, that's 20amps. If your battery is only accepting 50% of the charge through it, you will have to limit the TV and vhf if this is your only source of charge. I had a 10 watt panel that kept my battery charged all summer. On the weekends I used my Vhf to monitor, ran a 6" b&w TV 8 hour at night (two nights) running lights for about an 2 hours of night sailing, and minimal interior lights. I used candles and kero or propane lights. The important fact is that it had direct sun only in the weekends. I kept it in the boat till I arrived on Friday and went home on Sunday. If I were in the market for a panel now, I would try E-Bay. There is someone that regularly auctions off a 10 watt flex panel with a cord. I think it is worth about $110 on the market but is regularly auctioned for $69.00. It's spec's sound good for a small solar panel. I would hesitate spending money on anything less than a 10 watt panel. I like the flex panels but have only owned glass. I had no space to mount the glass so it lay on the deck. If you go larger or use two 10watt panels I would consider some regulation so you don't cook the acid/gel right out of your batteries. hope something here was worth reading. r.w.landau
