Solar Power Setup

[RyanR4288]

i have four deep cycle batteries 12v on my boat. i would like to charge them in the day and use them at night. What type of setup will need to fully charge them?

[Pete7]

Ryan, you need to work out what the total number of amp hours you will be using on average both whilst as sea and at anchor. You will probably use more at sea with external lights, VHF and auto pilot. When you have that information you can then start to work out what size panels you need.


Pete

[Bash]

My house bank holds 410 amp hours of power. This gives me a useful range of about 200 amp hours of available energy, since it's hard on the batteries to discharge more than 50%. I rarely use more than 100 amp hours per day, which means I can go two days without needing to worry about charging, for example if there's a day with heavy fog and no wind. I have 260 watts of solar, which means that on a sunny, summer day the panels will have recharged my batteries by early afternoon. I also have a 200 watt wind generator, which pretty much means I can sail through the night without depleting the house bank significantly.

You'll need to go through a similar budget to figure out what you need in panels. How much power, in amp hours, does your house bank store? How much power, also in amp hours, will you use on an average day? Once you know these two things, it's fairly simple to compute how much wattage you'll need for charging.