a bank of marine batteries

If you think it is frustrating when the battery dies on your smartphone, or laptop, imagine what can happen when a marine battery gives up the ghost on a luxury motor yacht!

Batteries play an important role on all vessels, including yachts. Batteries are the heart of any DC electrical system. Your motor yacht’s batteries will store the electrical power from your yacht’s generators or shore-based charging system, for “on demand” use as needed. Most vessels have a traditional 12 volt system that is made up of one or more “banks” of multiple batteries. The electrical system of larger yachts may have 24 or 32 volt systems.

Marine batteries on your yacht can provide electrical power to everything from starting your engines, to power for lights, computers, and entertainment systems, to alternative “get home propulsion ” systems.

All marine batteries need to be maintained – even those that are so-called “maintenance free.” The only difference between “maintenance free batteries” and others, is you do not have to add water to them. But, all batteries need to monitored and maintained in other ways. Most motor yachts are equipped with shore power systems and battery chargers to keep the batteries charged. The latest electronic chargers have built in sensors that will keep batteries from being destroyed by “overcharging.” This was a problem on older model “trickle chargers.”

shore power charge system

Charging Your Batteries with Shore Power

With battery technology improving significantly over the last few years, here are a few things to consider when you may be thinking about replacing existing batteries or retrofitting your yacht for an entirely new battery system.

Replacing or Upgrading to New Batteries

So what kind of batteries should your yacht have, and do you need to trade-out, or upgrade the battery and charging systems that are already on board? With there being so many different types of marine batteries and system configurations available today, that is not such an easy question to answer!

The performance and life expectancy of the batteries used on yachts is based on how often they can be charged, depleted, and recharged. That is known as “cycle.” You will want most of the batteries used on your yacht to be “deep cycle batteries,” meaning they can be charged over and over again many times.

The most basic and “standard” marine battery is a lead-acid battery, just like the one you would typically find in your car. Like the one in your car, its charge is maintained through a series of alternators.

Lithium Boat Battery

Lithium Ion Marine Battery

If you have a cell phone, laptop, or any other portable device that can be charged and recharged, then you have most likely heard of lithium ion batteries. These are also the kind of batteries that are used in electric vehicles and hybrids. Lithium is attractive for creating batteries, because it is one of the lightest of all metals and has an extremely high electro-chemical potential. Lithium ion batteries are “deep cycle batteries,” that can be made much smaller and in unique shapes than the traditional “lead-acid,” type of marine batteries. But, they are also much more sophisticated than traditional automotive or marine batteries, requiring complex internal circuitry and sensors to keep them operating safely and charging properly. This makes lithium ion battery systems very expensive.

A still efficient, but lower cost alternative to lithium ion batteries for your boat, is an absorbed glass mat battery configuration (AGM). AGM batteries are similar in power and functionality to lead acid batteries, but there is no fluid electrolyte to leak or spill, or evaporate. Instead, the electrolyte is absorbed in a mesh of glass fibers, hence the name “glass mat.” AGM’s are true deep-cycle batteries, and because of their internal configuration, they can be charged with most conventional chargers without fear of damage from modest overcharging, yet they do not require the internal electronics of lithium ion, so tend to be a less expensive option.

AGM batteries on yacht

A Bank of AGM Batteries

More Power to You

Regardless of the type of DC power system you have aboard your luxury motor yacht, FYM’s On Demand Yachting Solution gives “more power to you.”

Signing up for the program means your yacht will always be carefully monitored and well maintained for any issues with batteries, generators or any part of the electrical system. Should your battery system need upgrading or retrofitting, our skilled marine engineers, will be the first to know it, and you can be confident they will make the right recommendations for your yacht and needs. And, you will be able to monitor the entire process through your own proprietary On Demand dashboard!



Operating a motor yacht can be costly. You can reduce your expenses, and avoid costly repairs by keeping her well maintained. On Demand yachting from FYM can help. If you would like to learn more, or if you have any questions or comments about this blog post, do not hesitate to contact our Yacht Management specialists, or call us at (954) 900-9968.