Marine Batteries
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Marine batteries store electrical energy so electrical loads like lights, motors and pumps can operate. When boats have charging devices like alternators, solar panels or wind generators, batteries store electricity so charging devices don’t have to operate simultaneously with items that require electricity.
Types of Marine Batteries
There are three types of boat batteries: Starting batteries, deep cycle batteries and dual-purpose batteries. Those designed for starting engines are called cranking or starting batteries. Batteries designed for running loads are called house or deep cycle batteries. Dual-purpose batteries can be used for starting engines or powering house loads.
Battery Chemistries
Each of the battery types mentioned above is offered with a choice of battery chemistries, which are flooded lead acid, gel, AGM (Absorbed Glass Matt) and most recently, Lithium Iron Phosphate, such as those supplied to us by Relion. Your choice of battery chemistries should be based on the performance you desire balanced against how much you are willing to spend.
What are battery group numbers?
Just like the batteries used to power flashlights or drum-beating pink rabbits (D, C, AA, etc.), boat batteries come in standard sizes designated by their Group number. Battery group numbers denote the size of the case, location of the battery terminals and general configuration. A battery’s group number does not imply purpose, capacity, quality or other characteristics.
Cold Cranking Amps (CCA)
The term “Cold Cranking Amps” is used to quantify a battery’s ability to crank over an engine. Technically, this is the number of amps a battery can deliver at 0°F for 30 seconds without having the voltage drop below 7.2 volts. What this means to boat owners is that large engines, especially diesels and high compression gas engines require a high CCA rating.
Marine Cranking Amps (MCA)
Marine Cranking Amps (MCA) are identical in concept to CCA, except that they are measured at 32°F, which makes the numbers higher.
Note: The temperatures mentioned above in regard to CCA and MCA are used to standardize the measurement. We’re not implying that you would use your boat when the temperature is 0°F.
For more about marine batteries and what to consider when choosing batteries for your boat, please read our West Advisor articles How to Select a Marine Battery and Are Lithium Batteries a Good Choice for You?