I own a boat dock and want to put solar power on it for 12 volt lights and will also have an inverter to run my boat lift and some tools occassionally.

I have a 45 watts of panels (3 each, 15watt solor panels) and need a controller to hook uo between them and the batteries( 2 each 6 volt golf cart batteries)

Can anyone give me info on what size controller to get and where to get a good \$\$deal on one?

Also. I want to hook up some LED spot lights (similar to car fog lights) on the dock for night fishing,, again any suggestions where to buy them at a fair price?

Thanks Alot From A Newbie to Solar.....

• Solar Expert Posts: 5,433 ✭✭✭✭

Give us an idea of what your total daily loads are likely to be. My guess is that the ~45 watts of panel (HF?) are likely to put out significantly less.

The simple rule of thumb for battery based systems is 50%*4=total daily wh potential.

45 watts/2=22.5*4=90 watt hours per day.

I know there have been extensive discussions on these boards about boat lifts here before, you might do a search. My guess is that a single boat lift cycle will draw more in than you can replace in any given day.

Tony
• Banned Posts: 17,615 ✭✭

I have to agree with Tony; this is not a good scenario.

First up, 45 watts of panel isn't going to recharge 225 Amp hours of golf cart batteries:
45 Watts @ 77% efficiency (typical) = ~35 Watts / 14.2 charging Voltage = 2.4 Amps of current. That's about 1% of the batteries' capacity. No place near the recommended minimum of 5%.

Second, you start with a few 12 Volt LED lights for visibility/fishing. Then you add a boat lift. That's the difference between a few Watt hours per day and a few kilowatt hours per day. A lift runs from 1/2 to 1.5 HP, dependent on the size boat you need to lift of course. So this could be 1200 Watts running for several minutes. Basically, those batteries could run that for 1 hour maximum.

To properly recharge the batteries you've got you'd want at least 221 Watts of panel, preferably more (like 400).

So how much redesigning do you want to do and how's the budget? I know:
• Solar Expert Posts: 9,361 ✭✭✭✭✭