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Marine Batteries Vs Car Batteries: What’s The Difference?

car battery

They may look similar, but the battery in your car is very different from the one in your boat.

When choosing a marine battery, it’s important to invest in a model specifically designed for the rigours of wet environments. Here’s what sets boat batteries apart from automotive batteries.


A standard car battery is designed to produce a one-time high-energy jolt to the car’s starter that cranks the engine. Once the engine is running, an alternator takes over. It’s the alternator that powers your car’s air conditioner, lights and stereo. It also recharges the battery while you drive, so it’s fully charged for the next start.


Marine batteries are designed to both start the boat’s engine as well as maintain many of its accessories such as the GPS, pumps, refrigerator, and trolling motor. Consequently, these batteries need to dispense their energy for longer periods.


Differences Between Car Batteries and Marine Batteries

Here are the main differences between batteries used on cars and those used on boats:

  • Construction. The 12-volt batteries in cars have thin, porous lead plates submerged in sulphuric acid. The combination produces a chemical reaction that creates a concentrated burst of voltage.

The lead plates in marine batteries are thicker and denser than those in car batteries. This makes it possible for them to store more power and dispense it over a longer timeframe.

  • Durability. Cars have suspension systems to absorb the impact of potholes and bumps. This reduces stress on the vehicles’ components including their batteries.

Boats have nothing to protect their inner workings from the relentless bashing about caused by rough waters. Automotive batteries just aren’t built to withstand these types of environments. Manufacturers design and build marine batteries to take a beating without developing cracks, leaks or corrosion.

  • Rating. Car batteries are rated by cold cranking amps (CCAs), which is the battery’s ability to start a vehicle at below freezing. Specifically, a CCA rating measures the maximum amperage the battery can sustain for 30 seconds in -18 C temperatures.

Marine cranking amps (MCAs) measure the number of amps a marine battery can deliver at 0 C for 30 seconds and maintain 1.2 volts per cell, reflecting the conditions of a standard marine environment.

  • Cost. Marine batteries are significantly more expensive than automotive batteries because they are made of denser, sturdier materials as that are designed to withstand wet conditions.


Automotive and Marine Batteries in Western Canada

At Prairie Battery, we can help you select the best battery for your needs. We carry marine batteries and top-quality car battery brands, including our very own Gold, Platinum, and Silver series. Our Gold series features a marine line. To learn more about our products, contact us today. We have locations in Edmonton, Regina, Brandon, Winnipeg, and the Greater Toronto Area.


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