Online Course: Batteries

Learn about the different battery types and the pros and cons of the various options

This course focus on batteries and the electrical system around them. This includes:


Battery types, starter and consumer


Battery size, placement, and charging voltage


Battery monitor


Power for bow thruster, windlass and winch


Charger and charging


Categories: ,
  • Online Video Course
  • 115 Minutes Video Lectures
  • Theory, Examples, and Real-Life Videos
  • Watch on computer, tablet, or mobile
  • 3 Years Unlimited Acces to all Video Material
  • 10 Page E-book and Slides for Download
  • Instant Acces after Purchase
  • Support via Email
  • Personal Certificate

Which battery should I choose?

A question that many boat owners rightly ask. There are many battery types on the market today, including ordinary acid batteries, open and closed, GEL and AGM batteries, and the relatively new Li-on batteries.

The batteries must solve many different tasks, e.g., thruster, engine start, supply power for navigation equipment, lights, and radio for an entire voyage. Not all battery types are equally suitable for all tasks. If you choose the wrong battery, there is a risk that the engine will not start or that there is not enough power for the chart plotter.

In this course, you will learn about the advantages and disadvantages of the different battery types and where the individual types can be used with an advantage.

As an example, a GEL battery is well suited as a consumer battery. You learn about the difference in types and what considerations to make before you make your choice.

Many people doubt how many ampere-hours (Ah) you can draw from, for example, a 100 Ah battery. Many are in doubt about when to charge a battery and how long it takes to charge. You will learn a lot more about all this in this course.

The course emphasizes practical application with concrete examples, pictures, and video clips. Real-life stories support the theory.

In northern habitats, we have a relatively long period of cold and, in sailing terms, tiring weather. In the course, we discuss how to take care of your batteries when the boat is left untouched for a long time in a cold and windy harbor. You will also receive general guidelines on how to extend the life of your battery.


Another question for many boat owners is whether the charger fits the size of the battery bank. This is, of course, part of the course on batteries. One is to use the power optimally, but something else is to get recharged as quickly and efficiently as possible.

After the course, you will know why it pays to invest in a charger with Bulk, Absorption, and Float modes, instead of buying the cheapest charger online.

Batteries are closely connected to anchor winches and bow thrusters. These are two of the largest electricity consumers on board. In this case, it is about CCA (Cold Cranking Ampere) or, popularly said, how much power the battery can deliver, so the bow thruster provides the specified water pressure. In addition, how the control works.

This course is based on the course on Electrical Safety On Board, which you can watch first. The level is set so that most boat owners can join.

If you want to learn how to avoid battery problems while sailing, this is definitely a course for you.


Your Teacher

Lars Doktor Kristensen

With more than 20 years of experience in electricity and electrical equipment on everything from small pleasure boats to luxury yachts and large container ships through his own business, Lars knows what he is talking about.

Throughout the years, Lars has hosted several events in boat clubs in North Zealand. Therefore, he knows what type of knowledge is needed among sailors.

As a certified instructor, Lars is the perfect conveyer. His aim is to spread awareness of electrical safety across the world.