Solar battery charger for boat

[Zummie]

Has anyone ever used anything like the solar battery chargers in the link below to keep their boat's battery charged? Any downside? Can they overcharge?

http://www.harborfreight.com/5-watt-...ger-41144.html

[Kahi]

Has anyone ever used anything like the solar battery chargers in the link below to keep their boat's battery charged? Any downside? Can they overcharge?

http://www.harborfreight.com/5-watt-...ger-41144.html

Can overcharge but only after a long time. It's basically on trickle mode all the time at 1.5 watts and won't bring dead battery back. Bc it doesn't have a shut off or multiple modes/stages ie bulk or topping off it is basically good for maintaining especially if you have a low amp parasitic draw. Sail boaters all use them, mostly bc they don't have a better option while on the hook. It's cheap enough from hf.com to not care but I would keep track of it after 12 hours, then 36 hours to see the voltage of the battery..

[LuckyLady]

Has anyone ever used anything like the solar battery chargers in the link below to keep their boat's battery charged? Any downside? Can they overcharge?

http://www.harborfreight.com/5-watt-...ger-41144.html

I sold a set in the fall to a boat down in Florida and I have zero complaints back on them and I think that they are a wonderful idea