Solar battery charging for $35

[LeoJo]

I purchased a 5 watt solar charger from Harbor Freight and it seems to be working well.  I attached it to the top hatch with shoe goo and ran the power cord to the panel and master switch infeed.  I also added a panel mount voltmeter and so far the battery is always topped off when I run a power check.  The panel has a builtin diode that prevents discharging when the panel can not produce power (night).

[Marc]

Let me know how long it lasts and can you connect together for more wattage?  Thanks Marc

[AdriftAtSea]

Just remember, if you have wet cell batteries, the self-discharge rate in the summer time will probably be more than the 5 Watt panel can provide... so you'll either need more panels or to use a regular battery charger once in a while.

[LeoJo]

Each plate adds 5 watts of output  I would add more but do not want to clutter up the deck with solar panels.  I was going to fab a rack to go aft of the transum but wanted to keep the panel on all the time and not add to the length of the boat because I trailer.

[s/v Faith]

I purchased a 5 watt solar charger from Harbor Freight and it seems to be working well.  I attached it to the top hatch with shoe goo and ran the power cord to the panel and master switch infeed.  I also added a panel mount voltmeter and so far the battery is always topped off when I run a power check.  The panel has a builtin diode that prevents discharging when the panel can not produce power (night).

  FWIW,

with one of those Harbor Freight 5w chargers on the dash of my truck it kept the dual battery system (2 group 31's IIRC) topped off for over 9 months.  When I started it up it cranked well, and the amp meter did not swing very far.  I think 5w should be a reasonable maintenance charge, but you might add a couple more panels if you want to power a KISS electrical system (depth & VHF).  I would not try to run your refrigerator on it, and you can always have more, but for the ~$15 I paid I think it is a reasonable expenditure. 

[Captain Smollett]

I've got a 6 watt Sunsei, and it has done quite well at keeping my two 6V wet cells topped off...even replacing what the occasional bilge pump pulls out.  That was in SC summers of upper 90's to triple digits.

[LeoJo]

Everything I've read says that 5 watts should take care of my single 12v (wet) battery.  I have a 3.5 topping off the battery in my pickup that I run every 3 weeks or so and it seems to be doing it's job.  It sits on the dashboard and is connected thru the cig lighter port (why do even call that a cig lighter anymore?)  I've also added a digital voltmeter into the power panel so I can check the charge the day before I go out in case I need to plug-in the regular 3 amp charging system I have behind the panel. (It's a m/c charger).  Now if I can only find some good LEDs for the cabin, running and mast lights.  I keep the 15 watt radio off and use a handheld most of the time.

[AdriftAtSea]

LeoJo-

The best quality LED replacement bulbs are probably the SensiBulb LED replacement bulbs.  They're not cheap, but the quality and color of the light as well as the quality of the electronics used are really above everyone elses.  You can get them a www.sailorsolutions.com

[skip]

Solar Chargers are OK but realize that watts are not everthing. You need amps for replenishing the amps consummed by the electrics used on board that are battery powered. My $80 solar panel produces 18 volts and around 300 milliamp on a normal sunny day and is diode protected within the panel so the battery will not flow back through the panel. So 300 milliamp is like peeing into the ocean to make it over flow. It ain't gonna happen. I have left my Raymarine ST- 40 panel "on" for the week and returned the next weekend to a dead flat 1000 cold cranking amp battery. So be ware. But I don't need a battery to go sailing during the day. Just turn all consummable off. I have changed everything possible to LED's, plus a quarter turn disconnect switch and a four LED battery Charge Electronic Indicator from Fleet-Farm [$6] with an added  'push-to-test switch; Full-2/3-1/3-0~LED's will indicate the % of charge in the battery.

I have this solar panel sitting on cane feet to raise the panel up off my fwd hatch on my Com-Pac 19. You need a little air circulating under the panel to keep the panel cool AND if the panel is a matt style that lays atop the cabin then a risk of bubbling and blistering and discoloring the cabin material can and has happened to my dockmate's 27 ft Sovereign.
Just my two cents.

I should add that since there is NO SUCH THING AS RENEWABLE ENERGY due to ENTROPY WHICH IS A BALANCE AGAINST ENERGY IN NATURE. All energy wants to disapate to it's simplist form.

Electrons cannot be made to return to a battery without using more energy to make them go 'in', then it took to make them go 'out'. So to charge a battery around the clock and to keep up with the rate of discharge, just like making a fortune in boat building...you need to start with a bigger fortune. I gotta laugh at these Liberals.  But every little bit helps. Anyway I degress...

OHMS LAW for D.C. and A.C. Resistance Circuits.
Amps = Volts divided by Ohms
Ohms = Volts divided by Amps
Volts = Amps x Ohms
skip.

[AdriftAtSea]

BTW, just installed a small 25 Watt solar panel for winter battery maintenance.  It goes through the MPPT charge controller I have for my bigger panels.  It is mounted to the port side railing of the cockpit and looks like this:



It puts out about 1.8 amps during the middle of the day, even this early in the season. I am guessing that I get about 9.0 amp-hours out of it on a sunny week.

[Lone Palm]

Adrift,
That looks like a nice reasonable sized panel. What are the dimensions?
Also, what controller are you using?

I have a 10 watt panel on my C22 and I'd like to add another one and another battery.
I had a cheap PWM controller from WM, till it cooked a battery on me.

Where did you get them? I've been using Norther Arizona Wind and Sun.

Thanks.

[AdriftAtSea]

The panel is a 25W from Harbor Freight.  I got it for just maintenance charging over the winter. :)  It is about 14"x24" IIRC...

The MPPT controller I'm using is a BlueSky Solar Boost 2000E.  I also have two 130 W panels, which is why I got the SB2000E, but it is overkill for a smaller setup. 

If you haven't I'd recommend you read this Solar Power Primer I wrote.

Adrift,
That looks like a nice reasonable sized panel. What are the dimensions?
Also, what controller are you using?

I have a 10 watt panel on my C22 and I'd like to add another one and another battery.
I had a cheap PWM controller from WM, till it cooked a battery on me.

Where did you get them? I've been using Norther Arizona Wind and Sun.

Thanks.