Marine Alternator vs Car Alternator: What’s the Difference?

//Marine Alternator vs Car Alternator: What’s the Difference?

Marine Alternator vs Car Alternator: What’s the Difference?

As a boater, you may wonder why your boat alternator is more expensive than your car’s alternator. When it comes time to replace this vital part of your vehicle, you’ll discover there’s a significant difference in price.

The alternator is the hardworking part of a vehicle that charges the battery. Without a quality alternator, your battery won’t recharge when the vehicle is operating, leaving you without a reliable start. So yes, it’s an integral part of the vehicle.

Many boat owners wonder if they couldn’t just install a car alternator instead of a marine alternator in their boat? After all, who doesn’t want to save money where they can? Technically, it may work. However, in the long run, you’ll regret this choice. If you decide to go this route, you may soon be out of a functioning alternator again. This is because there are some significant differences between marine and car alternators. What are they?

Power Demands

Boats typically have higher power demands than cars. In addition to lights, boats also use battery power to run navigating equipment, the radio, AC/DC inverters, pumps, and winches, among other applications. The higher demand on the battery, the higher capacity alternator you’ll need. Today’s marine alternators take into account these high demands.

You could also find a car alternator that’s similarly designed to handle higher power demands. Some car owners add many features such as more powerful speakers and radios, video screens, alarms and more that also drain the battery. However, there are additional differences between marine and car alternators.

Cooling Requirements

Have you ever taken a look at a boat engine? Most designs tuck away boat engines into a protected space so that water and salt can’t quickly get in. While this is great for avoiding corrosion and damaging the engine, it isn’t so great for ventilation and keeping the engine cool. Today’s marine alternators take this into account and include a ventilation system. Sometimes the alternator is self-cooling, and other times a unique cooling subsystem is added.

In any case, this is generally different from car alternators that don’t require additional ventilation. Car engines typically have built-in ventilation systems in the form of the radiator and air movement. So, alternators for cars don’t include any particular ventilation systems.

Part Types and Materials

Boats face harsh conditions day in and day out. This is especially true for vessels that brave the ocean. Not only does the moist air get into the engine area, but briny salt breeze can make its way in there as well. This creates perfect conditions for corrosion. As a result, boat engine parts must be incredibly durable.

When it comes to marine alternators, manufacturers choose corrosion resistant metals such as stainless steel and may also use heavy-duty coatings. These changes can significantly help increase the life expectancy of your alternator.

Car and parts manufacturers usually don’t make car alternators with the same level of heavy duty materials and coatings. That’s because car owners typically protect their vehicle from the elements. Boats, however, must face moisture, salt, and harsh conditions daily, which is why their alternators are different.

Safety Concerns

Moisture in a boat engine creates other concerns aside from wear and tear. Boat engineers must carefully design engines to avoid the risk of electrical shocks. For marine alternators, this usually means double insulation, which helps prevent sparks and electrical shock, even when the engine gets a bit wet.


Boat engines do not enjoy unlimited space. As such, marine alternator manufacturers produce alternators in specific formats that will fit most boats. Often, this means that marine alternators are smaller than car alternators. So, although a car alternator may be cheaper and even meet the same power requirements, it may not fit in the boat. Of course, there are many other differences between car and marine alternators. Size is just another difference to add to the list.

Ultimately, marine and car alternators are now entirely different. While they used to be much more similar, over time, engineers have developed adaptations for both car and boat alternators. These adaptations have made the alternators better adapted for their purpose. Mainly, marine alternators must perform under challenging conditions that can easily result in corrosion, sparks and ventilation troubles.

Whether you’re searching for a marine or car alternator, Inland Alternators has what you need. Our friendly staff will be happy to help you find the perfect alternator that meets your vehicle’s specifications. Stop by or give us a call today!

By |2018-08-21T21:45:14+00:00August 21st, 2018|Uncategorized|0 Comments

About the Author:

Leave A Comment