Solar Charging on the Mooring

[christopher]

I've got a little flexible solar panel that came with my boat. I took a voltage reading on it and it said 19 volts. I didn't grab a current reading, but I will tomorrow. I read in Casey's "Good Old Boat" that when using a small panel to just keep the batteries topped off at mooring that you can wire the panel directly to the battery rather than through a regulator. Is this advisable or is it better to be safe and use a regulator?

[Maine Sail]

I have been using a Flexcharge PV7 for the last four years and the PO's used it for over five years while on a five year cruise. It does not over charge the batteries and has worked & performed flawlessly. While not a fancy MPPT controller, it works extremely well for the $60.00 they charge. I just finished a complete re--wire of my boat and the PV7 was about the only item not changed out and I re-used it. This inexpensive charge controller has never let me down and is used in conjunction with an 85 watt Siemens panel.

http://www.fourwinds-ii.com/v2/?c=flexcharge&i=003

It is the tiny gray box with the orange wire coming out of it..

[christopher]

That looks like a reasonable unit, but I'm really just looking to know if I can hook my panel directly up to the battery as Casey suggests in "This Old Boat". He recommends if using it for a float charge, that you can hook one panel up to each of your batteries directly with no regulator.

[Quetzalsailor]

I think you'll find (used to be plenty, anyway) plenty of used VW 12v solar chargers on eBay; they used 'em for their cars in shipping. A friend of mine always left his boat with a solar charger; so far as I know, there was no regulator. He simply used alligator clips and tagged onto the battery terminals.

I was thinking about solar chargers for keeping batts up to snuff over the week after we bought Quetzal. She has two group 31 deep cycle lead acids in one bank and an ordinary group 27 starting bat., so taking 'em home as I did with the previous boat to keep 'em warm and charged was less convenient. I Googled around, found the 'Battery University' in Saskatchewan whose guru said to fugetaboutit; the batts would not naturally discharge enough to be bad. http://www.batteryuniversity.com/ So, I did.

[Peter]

I'll second Maine Sail's recommendation. I have one of those little units, but mine is the PV7D for dual battery setup. I have two moderate-sized PV panels that keep both banks topped up, with no concerns of gasing or overcharging.