The 8 Best Marine Batteries of 2021

Power your boat with these top picks

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Marine Batteries

Tripsavvy / Chloe Jeong

The Rundown

Best Overall: Odyssey Marine Dual Purpose Battery at Amazon

"Fulfills the twin roles of a cranking and deep cycle battery with incredible efficiency."

Runner-Up, Best Overall: VMAX AGM Marine Battery at Amazon

"It’s an ideal power source for larger trolling motors."

Best Budget (Dual Purpose): Bass Pro Shops Battery at Bass Pro Shops

"Built to withstand repeated deep discharges."

Best Budget (Trolling): Mighty Max Deep Cycle Battery at Amazon

"Despite its affordable price, the battery offers all the benefits of AGM construction."

Best Trolling (Small Motor): Mighty Max Trolling Battery at Amazon

"An affordable, effective option for those that want to power a small to medium trolling motor."

Best Trolling (Large Motor): VMAX Deep Cycle Battery at Amazon

"Features AGM technology for increased shock and vibration resistance and reduced self-discharge."

Best Cranking (Medium Power): Optima Marine Battery at Amazon

"Delivers more power in a single burst than conventional flat-plate batteries."

Best Cranking (High Power): Bass Pro Shops X-900 AGM Battery at Cabelas

"Stands out for its high CCA rating of 1150 amps."

Choosing the right marine battery is a difficult task and one that takes into account several factors. The first step is to decide whether you need a cranking battery or a deep cycle battery. The former’s sole job is to provide the short, sharp burst of power needed to start your inboard or outboard engine. A deep cycle battery is made to deliver a smaller amount of energy over a long period of time and is used to power your trolling motor and/or onboard electronics (like a marine stereo). Alternatively, there are some marine batteries that fulfill both purposes.

Key features to look out for include the battery’s cold cranking amps or CCA (how much power it can supply within a short period of time), its reserve capacity (the length of time a fully charged battery can deliver 25 amps of power before being discharged to 10.5 volts), and its amp hours (the number of amps it can deliver in a 20-hour period). There are different types of marine batteries, but the best are generally AGM or absorbed glass mat batteries.

Read on to learn more about the best marine batteries for different boating requirements. 

Best Overall: Odyssey 31M-PC2150ST Marine Dual Purpose Battery

Odyssey 31M-PC2150ST Marine Dual Purpose Battery

Courtesy of Amazon

What We Like
  • Efficient

  • Good in cold weather

  • Long battery life

What We Don't Like
  • Expensive

Odyssey’s Marine Dual Purpose Battery fulfills the twin roles of a cranking and deep cycle battery with incredible efficiency. It offers 1150 CCA, giving it a massive cranking power capable of starting any recreational inboard or outboard motor, even in cold weather. It also has impressive deep cycling capability, lasting for up to 400 cycles at 80 percent depth of discharge. Rated to 100Ah, it should deliver 5 amps of current per hour for 20 hours, giving you plenty of time to troll your local lake or river without having to recharge.

A full recharge takes just four to six hours. The battery’s AGM design means that you don’t have to top it up with distilled water or worry about spilled battery acid as you would with traditional wet-cell batteries. AGM batteries are also more resistant to shock and vibration and have a lower self-discharge rate. Although expensive, it’s still cheaper than purchasing separate cranking and deep cycling batteries of the same quality.

Dimensions: 13 x 6.8 x 9.4 in. | Weight: 77.8 lbs.

Best Budget (Dual Purpose): Bass Pro Shops Pro Series Deep-Cycle Marine Battery

Bass Pro Shops Pro Series Deep-Cycle Marine Battery

Courtesy of Bass Pro Shops

What We Like
  • Long life

  • Durable

What We Don't Like
  • Not good for high horsepower engines

If you have a small to medium horsepower engine that doesn’t need all of the cranking power provided by the other dual-purpose batteries on this list, you can save considerable bucks with the Bass Pro Shops Pro Series Deep-Cycle Marine Battery. Despite a retail price of around $200, it has a CCA rating of 545 amps and a reserve capacity of 120 minutes at 25 amps.

Once your engine has started, the battery’s deep-cycling capabilities power your trolling motor and other electronics (your fish finder or electric radio, perhaps). It is built to withstand repeated deep discharges and is also conveniently quick to recharge. You can rely on the durability and vibration resistance of the AGM construction while the dual terminal design makes installation easy. Your purchase is backed by a one-year free replacement and 36-month pro-rated marine battery warranty. 

Dimensions: 6.75 x 8.75 x 10.87 in. | Weight: 54 lbs.

Best Budget (Trolling): Mighty Max Battery ML35-12 Deep Cycle Battery

What We Like
  • Affordable

  • Low maintenance

What We Don't Like
  • For small boats only

Well under the $100 price point, the Mighty Max ML35-12 Deep Cycle Battery costs less than a sixth of the price of the most expensive battery on this list. It is made with small-thrust trolling motors like the Minn Kota Endura C2 in mind and is rated to just 35Ah.

Some customers recommend wiring two batteries together to provide 70 amp hours for less than the price of a top-brand single battery. Despite its affordable price, the battery offers all the benefits of AGM construction including zero leaking or maintenance. It doesn’t require any ventilation and can be mounted at almost any angle—making it easier to fit it in around other accessories when deck space is limited. Its durable calcium-alloy grid promises great performance and an extended service life. 

Dimensions: 5.16 x 7.68 x 7.13 in | Weight: 23.25 lbs.

Best Trolling (Small Motor): Mighty Max Battery 12V 55Ah Trolling Battery

What We Like
  • Long lasting

  • Durable

What We Don't Like
  • For small boats only

The deep cycle Mighty Max Battery 12V 55Ah Trolling Battery is an affordable, effective option for those that want to power a small to medium trolling motor. Depending on the size of your motor and the speed at which you plan on traveling, it can last for a full weekend of fishing without needing to be recharged. It's the ideal fit for tenders, inflatables, fishing kayaks, and canoes.

The battery has a 55Ah amp hour rating and AGM technology. Sealed, spill-proof batteries are a safe, environmentally conscious choice that requires zero maintenance and can be stored at any angle in an unventilated battery box. The Mighty Max battery has a wide operating temperature range, making it a good choice for year-round use. If you’re not completely satisfied with your purchase, you’re protected by the manufacturer’s one-year warranty. 

Dimensions: 9 x 5.4 x 9.1 in. | Weight: 38.58 lbs.

Best Cranking (Medium Power): Optima 34M BlueTop Marine Starting Battery

What We Like
  • Fast recharge

  • Durable

  • Long life

What We Don't Like
  • Expensive

If your sole reason for buying a marine battery is to start your medium-power inboard or outboard engine, the Optima 34M BlueTop Marine Starting Battery is a trustworthy choice. It has a 100-minute reserve capacity and a CCA rating of 800 amps — more than enough to start most recreational engines, even in winter. The battery’s patented SPIRALCELL technology delivers more power in a single burst than conventional flat-plate batteries and allows for triple the number of recharges. It also recharges faster.

The battery’s tightly wound construction keeps plate movement to a minimum and offers 15 times the vibration resistance for reliable cranking power even in rough conditions. The sealed AGM batteries are spill-proof and maintenance free, and you can mount them in whatever position best suits your boat’s configuration. Infrequent boaters will appreciate the battery’s super-low rate of self-discharge, which means that it can hold its charge for up to a year as long as it’s kept at room temperature or lower.

Dimensions: 6.88 x 10.06 x 7.94 in. | Weight: 38.4 lbs.

Best Cranking (High Power): Bass Pro Shops X-900 AGM Battery

Bass Pro Shops X-900 AGM Battery

Courtesy of Cabelas

What We Like
  • Long life

  • Good for big boats

  • Fast charge

What We Don't Like
  • Expensive

For bigger engines that require extra cranking power to get started, choose Bass Pro Shop's X-900 Pure Lead AGM Battery in the Group 31 size. A dual-purpose battery capable of deep cycling to run your trolling motor and electric appliances once the engine has started, it stands out for its high CCA rating of 1150 amps. In warm weather, it can provide up to 1370 amps of electrical current. It has a 220-minute reserve capacity, keeping you out on the water longer, and a shock-resistant AGM design that works well in rough conditions.

Lab testing has proven that the battery is capable of 900 recharge cycles at a 50% depth of discharge. It can be stored for up to a year without recharging, and when you do charge it, it charges five times faster than regular wet-cell batteries. It is protected by a reinforced plastic housing and a three-year warranty. 

Dimensions: 6.77 x 9.78 x 13 in. | Weight: 65 lbs.

What to Look for in Marine Batteries

Type

There are three types of marine batteries: cranking, deep cycle, and dual. Cranking is perhaps better known as the starting battery. Deep cycle marine batteries, on the other hand, supply the devices (think lights, fans, plumbing, GPS, etc.) on your boat with constant, even power. A dual, as the name suggests, is both. You can't substitute a cranking for a deep cycle or vice versa. It's best to install separate batteries, but if your boat is small and there's only room for one, go ahead and get the dual-purpose battery.

Weight and Size

Marine batteries come in myriad weights and dimensions. Sizes are usually categorized by groups including 24, 27, 31, 4D, and 8D. You should check the dimensions of your existing battery to see what group your new battery will fall into. Making sure that you pick the right one for your boat sets you up for a good boating experience. Without the proper power, you likely won't be able to start your engine or run gadgets like GPS.

Price

Marine batteries can cost upwards of a few hundred dollars. However, they're worth investing in if you plan to use your boat often. Cheaper batteries may not have as much power, last as long, and need more repairs than more expensive ones.

FAQs

How long do marine batteries last?

Generally speaking, marine batteries will last anywhere between two to five years. However, that's entirely dependent on how well the battery is maintained. You can extend the life of your boat's battery by connecting it to a charger when not in use.

How do you charge a marine battery?

If you're looking to give your marine battery a boost so it runs like new, it's possible to give it a charge. It's best to start by switching the battery off and removing it from its box. From there, make sure you have the right charger for your battery size and connect the charger clips to the battery's terminals. Then switch on the battery—it should start charging. Smart battery chargers with LED displays will let you know when your battery is fully charged. When it is, switch it off, disconnect the clips and place the battery back in its box. It's as simple as that.

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