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Marine & Boat
Battery Buying Guide

What Type of Boat Battery do I Need?

Application Deep Cycle Dual Purpose Starting
Trolling Motor  Deep Cycle Recommended for Trolling Motor  Dual Purpose Recommended for Trolling Motor Starting Not Recommended for Trolling Motor
Live Well Pump  Deep Cycle Recommended for Live Well Pump  Dual Purpose Recommended for Live Well Pump Starting Not Recommended for Live Well Pump
Fish Finder  Deep Cycle Recommended for Fish Finder  Dual Purpose Recommended for Fish Finder Starting Not Recommended for Fish Finder
Outboard Motor
Deep Cycle Not Recommended for Inboard/Outboard Motor  Dual Purpose Recommended for Inboard/Outboard Motor  Starting Recommended for Inboard/Outboard Motor
Marine Lights Deep Cycle Not Recommended for Marine Lights  Dual Purpose Recommended for Marine Lights  Starting Recommended for Marine Lights
Communication Radio Deep Cycle Not Recommended for Communication Radio  Dual Purpose Recommended for Communication Radio  Starting Recommended for Communication Radio

Deep Cycle

Deep cycle marine batteries feature a heavy charge and discharge cycle, making them perfect for long-lasting power on fishing boats, kayaks, and any other watercraft using a trolling motor or electric motor.

If you're operating a live well pump, depth finder or fish locator, a deep cycle marine battery generates the reliable, durable energy you need.

Deep cycle, or deep cell batteries are designed with fewer, but thicker plates, which means they can be discharged at a consistent rate for a longer time, at a higher depth of discharge.

It also means they can withstand high temperatures while providing high electrical currents. Deep cycle boat batteries can be drained and recharged many times; starting batteries can’t. That’s why they’re typically used to power electric motors, and other applications, too.

Note: Deep cycle batteries come in both AGM and lithium chemistries.

Shop Deep Cycle Marine Batteries

Dual Purpose

Looking for something that does a little of everything? At the mid-point between starting and deep-cycle batteries you’ll find dual purpose batteries.

Dual purpose marine batteries provide the strong starting power you need for your engine, as well as the cycling capacity to keep your accessories running smoothly.

Look no further than the name. If you’re looking to save money and space, consider replacing two batteries with one. It’ll power your boat’s engine and all of your on-board applications at the same time.

Please note that dual purpose batteries are recommended for small-midsize boats that take shorter trips on the water.

Dual purpose batteries, while convenient, don’t offer the cranking amps of a dedicated starting battery or the same depth of discharge as a deep cycle battery.

Shop Dual Purpose Marine Batteries


Starting batteries provide the fast, strong power you need to take your boating adventures to the top. These batteries are best for powering an inboard/outboard motor, as well as accessories like marine lights and radio communications.

Similar to a car battery, a boat starting battery provides a short, powerful burst of cranking amps to the engine when the key is turned, which then turns over your boat’s engine.

The marine starting battery design features a wider surface to accommodate thinner plates, enabling it to provide high currents.

Starting batteries tend to have a relatively low capacity, but that’s all they really need to start the boat’s engine. And when the engine alternator kicks in, the starting battery is charged back up to its full capacity.

While their wide design is perfect for providing the initial cranking amps, it also limits these batteries’ capacity and depth of discharge.

Starting batteries should only be discharged at a small percentage, and shouldn’t be counted on to power on-board applications or as a trolling motor battery.

Shop Starting Marine Batteries

Why Choose Lithium?

Lithium is a Battery chemistry of Deep Cycle Marine Batteries

  • Up to 10x longer life cycle than a traditional lead acid battery
  • Charges up to 4x faster than a traditional lead acid battery
  • Low self-discharge
  • Twice the power of traditional lead acid batteries
  • 5-year replacement warranty on X2Power lithium batteries
  • Flexible installation
  • Consistent power
  • Lightweight, maintenance-free & super safe

Shop X2Power Lithium Marine Batteries

Marine Battery Care & Maintenance

No matter which battery you choose, it won’t work if it’s not cared for properly, especially in the off-season.

Follow these tips to maintain your boat battery.

  1. Get your current battery tested - Have your battery tested for free at Batteries Plus, especially if you've had your boat in storage for a season or more.

  2. Get yourself a battery box - Use a battery box to minimize the impact of vibration and also to keep your battery secure. (Note that sometimes they’re required by law.) An unsecured battery can cause damage to both the battery and your boat.

  3. Keep connection points clean and electrolyte levels up - If you notice corrosion on your battery terminals, clean it up with a mixture of baking soda and water. If your boat carries a flooded battery, monitor the electrolyte levels before charging or operating your boat.

  4. Waterproof chargers for the win - Waterproof chargers are perfect for your time on lakes, rivers or other waterways; you’ll never find yourself on the water with a dead battery.

Note: Choose a charger with a high enough amperage for your battery. The Duracell Ultra Automatic and Ultra Marine chargers are good options.

5 Simple Steps to Prolong the Life of Marine Batteries

  1. Keep track of your battery status. Monitor its state of charge/discharge and never let the charge fall below 50%. Letting batteries fall lower than a 50% charge regularly will dramatically reduce the life of your battery.
  2. Choose an adequate battery size for your needs. Using a battery that is too small will force the battery to use more power than necessary and reduce the usable life of the battery.
  3. Minimize your power demands. Arguably the most inexpensive way to increase life expectancy of your battery is to turn off unnecessary electronics when not in use, like fish finders, lights (when not necessary), etc.
  4. Add an alternative energy source like solar panels or a wind turbine to help keep the batteries charged to optimal levels.
  5. Equip a smart charging regulator to create the ideal charging environment to charge the battery with the boar’s alternator.

Common Marine Questions

Should I keep my boat battery plugged in all the time?

The answer to this question largely depends on the type of charger that you have. Many newer chargers are "smart" meaning they will constantly analyze the battery state as it's charging and automatically change the charging mode to match the needs of the battery. These chargers will shut off when a charge is not needed and is completely safe to leave connected.

If you have a charger that is not automatic you will want to plug in the charger and leave it plugged in until the battery is charged. As soon as the battery is fully charged you will want to disconnect the battery from the charger to prevent unnecessary damage to the battery.

How often should I charge my marine battery?

Generally speaking, your batteries should be "fully charged" at all times if possible. The worst thing that you could do is come home after a long boating day and let your used batteries sit. Ideally, you will want to fully charge your batteries at least once a month to ensure a long life. Using an automatic charger is a foolproof way to ensure batteries stay charged and ready. Plug in the charger after every trip and let it do all of the work.

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