The capacity of the battery bank of a sailboat

Introduction.

In the previous chapter we completed the first part of the design of our main 12 volt (V) direct current (DC) electrical system, which was to estimate the total daily consumption of the equipment we use on board with the boat under sail. In our example, the “Prince Azur”, a 12.5 meter ocean-going sailboat, has an estimated daily electrical consumption of about 280 amps.

In this chapter we will address the second calculation that is necessary for the design of our electrical system, and that is to determine the total capacity of batteries we need on board; that is, the sizing of the battery bank of a sailboat. In addition, we will see how we can organize in an effective way the different battery banks.