I really hope that everyone out there is using LED lighting by now. The savings in electricity compared to regular filament bulbs are incredible.
But electricity can be a bit complicated. Amps, Amp hours, Watt, Volts and current? What?!
Now what then? It’s a mine field out there. Batteries will show how many Amp hours they have, and products show how many amps they use. Sounds simple right? Well, it is, at least if you know that Amp hours (Ah) are ampere used per hour. So if you had a 83 Ah battery and you have a product using 1 A of current, that product could (theoretically) be run for 83 hours.
It might be easy to just let an electrician deal with that stuff for you, but if you are on a budget or at sea, that might not be an option. You really should have at least a basic understanding of the electronics system on your boat.
The first step on planning your electric system is knowing how much power that you need for the equipment you have and how often you will use this equipment. Make a list of items and how much you will run them. A refrigerator will be turned on 24/7, but an anchorlight will only be turned on for perhaps 12-hour periods, certain days? Ambient lighting will probably only be used for a few hours per day.