Marine alternator

A marine alternator is a device used to generate electricity on board a boat. It is usually powered by the boat's main engine, which drives the alternator in rotation. It transforms the mechanical energy of the engines into electrical energy.

Generally used as a battery charger, the electricity produced is stored in a battery and then used to power the devices on board the boat. The boat alternator is an essential accessory, so no energy is lost.

Discover our range of 12V and 24V alternators. These alternators are specifically designed to withstand marine conditions.

Whatever the amperage or voltage your electrical installation requires, you will find the marine alternator(s) you are looking for at the best price in this section.

Do not hesitate to contact our team for help in choosing your alternator. The stock status or the restocking dates are generally indicated in the product list. Opt for a home delivery or in a relay point.

1 139,90 € 1 273,20 € -10%
In stock within 48h/72h
  • -133,30 €

1 109,90 € 1 243,20 € -10%
In stock within 48h/72h
  • -133,30 €
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Alternateur pour bateau


When changing your alternator or adding a second one, it is important to take into account a few specific characteristics. 

First of all, the alternator for boats differs in some essential points from an automotive alternator. All the parts of the marine alternator are tropicalized, in other words, they are not subject to corrosion (sealed bearings, anti-corrosion, etc...) and are therefore suitable for use at sea and resistant to water. In the same way, the bearings benefit from a " lifetime lubrication The bearings are "greased for life", requiring no maintenance. 

In addition, for our boats, it is often necessary that the ground be insulated .

You will have, in this section, a large choice of12V or 24V (Volts)alternators , of various amperages, with right rotation, left rotation, with radial blades or with right and left rotation or with and without pulley.

Our Comptoir Nautique advisors will be able to provide you with all the information you need about the reference you need: don't hesitate to contact them by e-mail or by phone.


Themarine alternator converts themechanical energy produced by the engine into electricity, which can be used to power the electrical appliances and equipment of the motorboat or sailboat.

Marine alternators are generally smaller and lighter than shore-based alternators, making them easier to install on board a boat. They are also designed to withstand harsh marine conditions, such as rain, salt and vibration. If you're looking to buy a marine alternator, it's important to choose a model that fits your needs in terms of power and size.

The operation of a marine alternator is similar to that of a conventional alternator. The alternator is powered by the boat's main engine, which drives a rotating rotor. The engine is connected to the alternator with a belt that allows the rotation of the alternator (like a pulley). The rotor is surrounded by an armature coil, which is connected to an electrical circuit. When the rotor rotates, it generates a magnetic field that induces an electric current in the coil. This alternating current (AC) is then rectified by a rectifier to produce direct current (DC) electricity, which can be used to power electrical appliances and equipment on the boat or recharge batteries.

It is recommended that a regulator be used with a marine alternator to control the voltage and current produced by the alternator. The regulator keeps the voltage constant, which is important to protect the boat's electrical appliances and equipment. The regulator can also protect the alternator from overloading, which can extend its life.

If you use a marine alternator without a regulator, the voltage and current produced by the alternator may vary with engine speed and the load on the electrical equipment. This can cause damage to the boat's electrical appliances and equipment, as well as the alternator itself. By using a regulator, you can avoid these problems and ensure stable and safe operation of your marine alternator.

Alternateur marin
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