Hooking up solar charger

[rbh1515]

I am getting a new slip this year, and the electrical hookup is further away, and the cord would have to go across the finger pier.  Since I just have one battery, and don't really use it for much other than the bilge pump (which never runs) and lights (which I don't use a lot), I thought maybe I would just go with a solar charger.  Does anyone know...can I just plug the solar charger into the same plug that I plug my shore power line into?
Rob

[rbh1515]

After thinking about it, I would probably be best hooking a solar charger directly to the battery.  The plug in is AC and the solar charger is DC, so I would have to make some modifications......
Any suggestions on a nice solar charger.  What kind of output should I get?
Rob

[alsantini]

Hi Rob.  First off Do not connect the solar panel up to shore power.  I have used for 14 years a flexible 10 Watt panel.  It was purchased from West Marine and has nature in the name.  I bought a flex panel so that I could strap it to the boom and since my slip faces East, it is easy just to put it on the boom facing South for max current.  There are holes with grommets at the corners that work well with short bungees.  It came with a short (<foot) connection cord that stays on the battery.  The panel has an 8 foot cord that plugs directly into the connection cord.  Very simple and effective.  It keeps the batteries up to charge and will recharge over a long period of time.  I use the battery for a few days up in the Apostle Islands running a GPS, VHF radio and cd player plus 2 lights in the cabin.  Once home I connected up the panel and left the boat.  Five days later the battery was fully charged.  Output in full sunlight is around 3/4 amp or about 7 Amp Hours replaced in 10 hours.  A couple of times a year I wipe the panel down with clean water and a rag and I am good to go.  My Com Pac Eclipse has two batteries (not sure why - PO thing) and I figure the panel will just barely supply the current needed.  Two summers though and they stayed up on charge.  I am sold on solar especially since I do not have power at my slip.  Sail on...    Al

[Dogboy]

I have thought of this too.  I do not leave the shore power plugged in unless I'm on the boat.  I charge up the batteries on a smart charger before launch, and find with the motoring I do and the occasional overnight with the battery charger on that I'm fine.  The thing about solar that has me tentative is the potential to overcharge the batteries.  I think you might need a controller if you plan to leave the boat for long periods with no battery discharge.  I'm by no means an expert, just saying what I think I've figured out in my spare time researching this.

[Lafayette Bruce]

Rob-
If you go with anything bigger than a 5 or 10 watt charger, they recommend getting a controller so that you don't over charge the battery(s).  Keep it simple (and cheap) and go with a smallish one.
Lafayette Bruce

[Restharrow]

I had a small solar charger hooked directly to our battery on the CP23.  Left the charger on the cabin hatch ALL the time with no issues of overcharging one battery.  I now have a slightly larger solar charger on our CP25 and have connected it to a controller for the two batteries.  I like the controller because I can see if the batteries are charging or not.  My new charger is a 14 watt "Power Film" - 42" x 14.5".  The 7 watt Power Film panel is 23" x 14.5" and perfect for a CP23

Steve
CP 25
Lake Champlain and Coast of Maine

[MKBLK]

On my CP16 I have a large deep cycle mounted forward of the compression post. My battery is used primarily for trolling motor propulsion. When on the "hard" in my driveway, I use a trickle charger to keep it fully charged. On really cold days (SE PA), I hook up my car charger for a bit. I believe that a battery loses about an amp a day in winter. On water, or where 110v isn't available, I use a portable 15 watt (briefcase) solar charger with controller (both from HF). Very pleased with its performance, plus I can use it for other things like charging my cell phone or marine radio.

Marty K.
81 CP16 Pegasus

[Seadub]

Marty, I'm using the same setup you have, basically. I have a 55# thrust Minn Kota trolling motor and a deep cycle Exide battery mounted in the bow. Just ordered a 100 watt solar panel that produces about 5 amps in optimum conditions. it's a light 4#s so I have a few mounting options. We want to do multi-day (mostly lake) excursions and haven't ruled out a gas motor, but the Admiral really hopes we can keep gas off the boat. I lean toward it for the security and power, but wondered about your experience with your setup? Have you been able to stay charged enough to meet your needs? Also curious what gauge wire you use to connect the motor and battery. I have 6, but wonder if I should beef up to 4. Any feedback would be appreciated!
Clint

[HeaveToo]

When I am cruising I run a 100 watt flexible panel. It goes through a Genasun GV-10 MPPT charge controller. It is a nice setup because I carry the solar on my bimini.

For your set-up you would be okay with less. I would still do a charge controller for the panel. 10 watts would be a good size. Not all charge controllers are equal. For smaller panels Genasun is supposed to be the best.  You want a MPPT charge controller. 

For more info Google Compass Marine and look at his article page. He breaks down solar panels well

[Craig Weis]

I buddy laid a flex solar panel directly on the deck of a balsa/fiberglass cored doghouse roof with no air space under it and made a huge air bubble that went away when things cooled down. Just saying ...

Craig.

[rbh1515]

Mine has little feet in the four corners that raises it up.  I hate balsa cored decks...they are always eventually a problem.  No balsa in the deck of my boat!!
Rob

[ChuckD]

Another Yes vote for investing in a controller:
https://youtu.be/z5RtZe9AW2E

[MKBLK]

Clint - Sorry for the delay in this post... been busy!

100 watt?! Wow, that's huge. I do have a 2hp Johnson 2 stroke, but there's nothing like the security the MinnKota supplies. Especially if the sun is shining. The MinnKota is connected to the battery (which is forward of the compression post) via a pair of (modified) battery jumper cables. I like them because of their heavy insulation. I figure if they're good enough to jump a car, they're good enough to run my MinnKota. I have a 50 amp fuse in-line (obtainable from Best Buy or the like complete with very heavy cables).

Since Pegasus is kept in the driveway at home 99% of the time, I have easy access to my car battery charger so I "top" off Pegasus' battery when I get home. I just bought a pair of small 1.5 watt solar panels (HF - $15.00 ea.) that hooked up in parallel (DON'T HOOK UP IN SERIES!) keeps the battery full. Although I like the 15 watt "briefcase" solar charger, I don't have much room on the CP16 for it. I tried it on the fore-deck but it takes up all the standing room - not good. The new, little guys can exist just aft of the air vent and (hopefully) I won't stand on them. I attach the panels to the deck with Velcro and run the cables through the vent. Actually, a bigger boat might solve the problem!

Even on the "hard", I do use the battery to maintain the VHF charge and occasionally run the bilge pump to clear out rain water that mysteriously gets in. In winter, as I mentioned above, I use a trickle charger for mere pennies.

Marty K.

[Seadub]

Marty, thanks for the advice, and no worries about any delays : I've been sorting things out and having a fine time. My (probably unrealistic) goal with the 100 watt charger was to be able to use the trolling motor for extended periods if needed and still have juice. I gave up on it because I finally realized that the trolling motor is freshwater only and I plan to do some ICW and Charleston Harbor sailing (or motoring). I'll keep the trolling motor for reliable, silent entry and exit on our local reservoir, but it'll be the light duty motor, with a small 4 cycle to handle tides and currents.

[Craig]

Harbor Freight sells a 1.5 watt charger for $12.99. At at that price you could by two! I have used one and does a nice job of trickle charging. No regulator needed.

http://www.harborfreight.com/15-watt-solar-battery-charger-68692.html