Years ago when we bought ShortSail we needed a solar system. The boat was going to be parked on a mooring without any kind of shore power to keep the batteries up. Not that it mattered a whole lot though, ShortSail had its AC system ripped out years ago leaving just the DC system around the boat. So even if we’d have had shore power, there was nothing to hook it up to. So DC charging and solar it was going to have to be.
You kids today with your solar might not remember just how expensive those panels, charge controllers, and other equipment used to be. The price has come down a lot since 2012. #ThanksObama I guess. At the time we ended up buying a 45 watt kit from Harbor Freight. I don’t know if we ever reviewed it, so I’ll take a moment to do that now.
Review of the Harbor Freight 45watt Solar Kit: It produces electricity. That’s about the only good thing I have to say for it. Oh, and in 2012 it was pretty inexpensive for a whole system. It came with three long thin panels rated at 15w a piece, a charge controller, and some other garbage light bulbs and stuff that I don’t think anyone has ever used. When you plugged the three panels together and plugged them into the charge controller, it would read a voltage. When we used to come down to the boat the batteries would be charged, the radios would work, and the lights came on. So that was good.
I guess the charge controller that comes with the Harbor Freight kit is actually pretty terrible. At night, it doesn’t stop the batteries from trying to power up the panels. I didn’t even know such a thing was possible until years later when I was looking at possible wind power. All this thing did was allow voltage to pass through. So during the day, when the panels were in the sun light they charged the battery. The panels had higher voltages than the battery so the electrons flowed panel -> battery. But at night, when the panels were shaded by the Earth, the electrons flowed out of the battery and into the panels. Not ideal for what we were using them for. You can buy a diode to put in line with the battery that will stop the back flow, but I never did it. I’ve got 100 of them sitting in my electrical box though if you want some. Just let me know.
A better charge controller is sold at Harbor Freight that is compatible with the system. It gives you a green light for charged, a yellow light for charging, and a red light for open circuit. We used that one for years. Again, the battery was always charged, so we didn’t think much of it.
After we divested ourselves of ShortSail we took the panels home and mounted them on the roof of the house. We purchased a better charge controller that told the current that the panels were producing. When I first mounted them in April of last year the (now) 4 panels that I had would produce close to 3 amps of current. This year, they produce 2 amps of current. If we do the math, that’s like what, 20 watts? Not so good. The panels did sit in a salt water environment for years, and then have been on my roof for another year, but 20 watts out of a nominal 60 isn’t very good.
Time for some new panels.