How to Select the Right Marine Battery

How to choose the right marine battery

Boat batteries, (or marine batteries), are crucial to the optimal operation of your boat. You need a reliable battery if out on the water and, the best marine battery for your boat depends on your needs and budget.

However, it’s helpful to have an idea of brand names to try and models to consider before you shop. The battery brand names listed on the left are popular batteries that should serve you well and give you an excellent starting point for your search.

How do you choose a marine battery that will meet your requirements and, power? It needn’t be confusing if you're buying your first battery, so this guide will break it down so that you can be ready for your next voyage.

Wondering what kind of batteries you need for your boat? What's the difference between a deep-cycle battery and a cranking battery? And what's the best way to charge your marine batteries?

Here's a video to help you make the right marine battery choice.


Marine batteries come in a wide selection, so by looking at 5 different attributes of a marine battery it will assist you to select the right battery for your boat.

First, decide what type of marine battery you want.

Marine batteries are divided into starting batteries, deep cycle batteries and dual-purpose batteries.

Starting batteries are intended to put out a large amount of current for a short period of time like you need when you're starting a gasoline or diesel engine. A starter battery, for instance, is a 12-volt battery that works to start your engine. These are also called cranking batteries and, their job is to start your main engine using a lot of juice initially and, then reducing the charge.

A deep cycle battery puts out a smaller amount of energy for a long period of time. A deep cycle marine battery is designed to power peripherals, such as a trolling motor, onboard electronics, fish finders, and radios. They consume power more slowly, allowing onboard electronics to run continually.

A dual-purpose battery is a sort of blend of the properties of the two.

Ideally, you would have both a starting battery and a deep cycle marine battery on your boat.
Second, you may want to consider a maintenance free, sealed battery, either one of the AGM batteries or possibly one of the Gel batteries.

These batteries are completely sealed with pressure relief caps on top, so even if you turn them upside down, like if you were to capsize your boat; you’re not going to spill out any electrolyte. These batteries are extremely reliable and we highly recommend them.

Third, batteries come in a variety of different sizes. Your boat may be designed to take a battery of a very specific size, but frequently you can actually get a larger battery by changing the battery box and using more of the space available.

So, whenever you’re replacing a battery think about upgrading to a larger size if you have room.

Many boats are underpowered, but this is easy enough to remedy with the right marine battery. Figure out how much power your boat consumes daily on average. List the appliances you want to power, as well as the amp draw of each (you can figure this out by dividing watts by volts).

Next, determine how long you use each appliance in an average 24-hour period. For example, say you come up with a power consumption of 100 Ah (amp/hour). Getting a 100 amp battery is not good, though, because the capacity is measured by the intervals between charges. With 100 Ah, you would have no reserve.

Typically, you want about four times your average consumption, so a 400 Ah battery will be best. One more thing to note: If you keep your battery charged up to about 50 percent capacity, you can extend its life dramatically.

Fourth, since marine batteries lead a fairly tough life, you may want to select a battery that has a longer warranty period. Battery warranties vary from about 18 months to 5 years. It may be worth your while to consider a battery that has a longer warranty.

Finally, if you find you’re replacing your batteries more frequently than you should be you should consider having a marine electrician, or possibly a boatyard, look at your electrical system to make sure it’s charging your batteries correctly.

While there are a wide variety of batteries available, we think if you follow these 5 selection criteria you can find the right battery.