Updated: December 2017

deepcycle marine battery

Marine Battery Reviews:

  • What are Marine Batteries?
  • Cranking vs. Deep Cycle Batteries
  • How much does a Marine Battery Cost?

Finding the Right Marine Battery for Your Boat - Boat batteries, or marine batteries, are crucial to the optimal operation of a boat. Without a reliable battery, you are dead in the water, so to speak. How do you choose a marine battery that will meet your needs, power your boat, and keep you afloat no matter where you are? It can be confusing if you're buying your first battery, so this guide will break it down, covering cranking/starter batteries and deep-cycle/trolling batteries, so you can be ready for your next voyage.

We recommend starting with the brief video below - it covers both types of batteries, sealed vs. conventional, size, and basic maintenance.

What Kind of Marine Battery Do You Need?

There are two basic types of marine batteries, so take the time to decide what you need and the functionality you would like. A starter battery, for instance, is a 12 volt battery that works to start (surprise!) your engine. These are also called cranking batteries. Their job is to start your main engine, using a lot of juice initially and then reducing the charge. A deep cycle marine battery, on the other hand, 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. These 2 types of batteries are constructed differently, with more thinner lead plates for starter batteries and fewer thicker plates for trolling batteries.

Finally, you can find some batteries that can do a bit of both, called hybrids. Most marine batteries you see are hybrids, so if you'd prefer cranking or true deep cycle, make sure that is what you get. And remember, cranking and deep cycle marine batteries are designed for different purposes, so you can't use them interchangeably.

Ideally, you would have both a starting battery and a deep cycle marine battery on your boat. If you have to choose one or the other, a hybrid will do. Keep in mind, though, it isn't as efficient at starting an engine as a cranking battery and isn't as efficient at running electronics' discharge/recharge cycles as a deep cycle. This is more a compromise, but for most boaters, a hybrid should do the job perfectly well.

What Size Boat Battery Do You Need? - 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. 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 note: if you keep your battery charged up to about 50 percent capacity, you can extend its life dramatically.

marine batteries

Boat Batteries - Cranking and Deep-cycle

Apart from our own experience, we found 4 sources to draw information from and they are MySears.com, Basspro.com, Yachtsurvey.com, and Amazon.com. All offer-up expert opinions on marine batteries and consumer reviews that have been posted to their website for you to check out. You can also go directly to a boating shop or stores like Walmart. A Walmart marine battery is sold only in their stores, while you can get a marine battery charger online at their website. Again, reading owner comments and feedback online is a great place to start and learn which models are the best performers. You can browse the top selling marine batteries online here.

Marine Battery Maintenance

Proper maintenance is required to keep your battery performing optimally - click the image below to check out several maintenance videos. boat battery

Best Marine Batteries:

The best marine battery for your boat depends on your needs and budget, but it is helpful to have an idea of brand names to try and models to consider before you shop. The following are popular batteries that should serve you well and give you an excellent starting point for your search.

As you look for marine batteries, you will see one name popping up again and again. A favorite with both Amazon reviewers and Buzzillions, the Die Hard PM-1 Platinum Marine Battery (find it at Sears.com) features 205 minutes of reserve capacity and 1150 cold cranking amps. The corrosion-resistant battery has high quality tin-coated brass terminals, military-grade construction, superior vibration resistance, longer off-season storage time, deep discharge recover, 99.9 percent virgin lead plates, high purity grade acid, absorbed glass mats (AGM), non-spillable design, absorbed glass mat construction, and three-year free replacement limited warranty. It can act as a starting battery and a deep cycle battery. Reviewers like the AGM construction, reliability, durability, and replacement warranty (vs. a pro-rated warranty with other batteries). Unlike most other AGM batteries, this one isn't plagued by corrosion and isn't made with recycled lead. This ensures a longer service life, which helps alleviate the price. You can find the Die Hard at Sears for about $275.
trolling battery

Another brand worth looking at is Odyssey. These are standard issue on some boats, and it is used in tanks, ships, fighter jets, and other military applications because of its remarkable durability. Another AGM battery, an Odyssey can last between 6 to 10 years. The Odyssey is an upgrade, both in quality and in price, from the Die Hard. The Odyssey 34M-PC1500ST TROLLING Thunder Marine Dual Purpose Battery, for instance, features great starting power and deep cycling capability, up to 400 cycles at 80 percent, twice as much power and three times as much life as a standard marine battery, pure virgin lead plates, high conductivity, brass terminals plated with tin that are made of corrosion-resistant materials, well-guarded terminal seal, sealed design for internal gas recycling, self-regulating relief valve, flame retardant cell containers, robust internal cell connections, 15 percent more plate surface than standard batteries, and 40 percent more reserve capacity. Many hybrid marine batteries are compromises: Odyssey really isn't. And you'll pay for it! It costs about $300.

Both the Die Hard and the Odyssey marine batteries will treat you well, and if you care for your battery properly (keeping it at least 50 percent charged), either will last for years. A less expensive choice to think about is Exide's marine batteries. Exide is a major manufacturer of auto batteries, and a marine model may be an affordable addition to your boat. The Exide MC-31 MEGACYCLE AGM-200 Sealed Maintenance Free (AGM) Marine Battery, for instance, features 700 CCA (the number of amps a battery can support for 30 seconds at 0 degrees F) at 0 degrees and 840 CA at 32 degrees F, 200 minute reserve capacity, dual terminal design, two times better cycling, 12 times more vibration resistance, and 40 percent greater charge acceptance compared to other 31 series flooded batteries, and a two-year "no hassle" nationwide free replacement warranty. The Exide is $173 (see all Exide marine batteries here). Again, if you keep it charged and maintain it properly, the Exide should serve you well.

marine battery review

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