In the last two chapters we took a deep and considered dive into analyzing the electrical loads on our boats and thinking about ways to reduce said loads through smart systems thinking. Now we get to the payoff: How to calculate optimal battery bank size or, alternatively, how to live with the battery bank size we already have. I have built a spreadsheet to make the whole process easier. And I have updated my thinking on lithium batteries too.
In the last chapter we looked at some big loads that take electricity from our battery. In this chapter John covers watermakers and diesel furnaces and shows how system thinking can save us from having to install a silly-sized battery bank.
Two core decisions we must make when designing a cruising boat electrical system for living aboard full time and making offshore voyages, are the size of the battery bank and which charging sources we will need: generator, solar, main engine, wind, etc.
But the first thing we need to do, before getting into all that fun stuff, is think about electrical consumption and how to keep it reasonable.
Being able to accurately monitor our batteries is a vital function for all cruisers, but which of the multitude of systems offered should we buy and install? John defines the functions we actually need, and then recommends a monitor.
It’s tempting, when selecting a complex piece of gear like a battery monitor, to dive straight into the details and features, but that’s a near-sure route to a bad decision. First let’s take a giant step back and look at the two main types of monitors and decide which is right for each of us.
These days, most boats with AC generators have significant DC (12- or 24-volt) battery banks that need to be charged regularly by the generator. But often that process is horribly inefficient. The good news is that the fix is easy, simple, and relatively inexpensive.
John recently replaced the house battery bank on Morgan’s Cloud. But before starting the project he had a big decision to make: which battery type. Here’s a look at the options he considered, starting with lithium.
The claims made for battery pulse desulphators seem to make them ideal for voyaging boats. A cheap, easy to install gadget that will dramatically extend your expensive batteries’ lives. What’s not to like? But do they really work? John takes a look.
Electricity, batteries and how to charge them are the source of more confusion in the cruising world than just about anything I can think of. But suppose you could really understand electricity? Now you can, and it’s not hard. Read on.
Nothing on this website or in direct communications received from us, or in our articles in the media, should be construed to mean or imply that offshore voyaging is anything other than potentially hazardous. Dangers such as, but not limited to, extreme weather, cold, ice, lack of help or assistance, gear failure, grounding, and falling overboard could injure or kill you and wreck your boat.
Decisions such as, but not limited to, heading offshore, where you go, and how you equip your boat, are yours and yours alone. The information on this web site is based on what has worked for the authors in the past, but that does not mean it will work for you, or that it is the best, or even a good way for you to do things.