Back to News

A Guide to Choosing the Best Boat Battery

A Guide to Choosing the Best Boat Battery

As more technology is added to boats, more and more power is required to keep things afloat. In this article we go over some of the most important things to consider when shopping for a boat battery.

12v 75Ah Lithium Battery

Purchasing your first boat battery can be a little overwhelming. You're entering a world full of strange jargon and acronyms that can become confusing at times.

Whatever you do, don't let buying a battery take the fun away from boating or angling. Stay calm and read this guide to see exactly what you need to get back on the water.

Types of Marine Batteries

Before even thinking about purchasing a battery, it's important to understand the different types available. 

You'll run across two main categories: cranking and deep-cycle batteries.

Never substitute one for the other, as the battery will overheat or it won't have enough power to supply the boat. Instead, aim to purchase one cranking battery and one deep-cycle one.


Cranking batteries are made for exactly what the name implies. They provide the power to start your boat. To do so successfully requires a powerful, short burst of energy, which is supplied to cranking batteries through their many thin lead plates.


Deep-cycle batteries supply power to other necessary accessories, including the following:

  • Trolling motors
  • Fish-finders
  • DC lights
  • Radios

Such equipment doesn't require the burst of power necessary to start the boat motor. Instead, these pieces require extended power at lower rates.

As a result, deep-cycle batteries are recharged at the end of each day. To avoid damage from constant recharging, they are made with thick lead plates.

Option # 3 (less popular) = Dual-Purpose

You may also run across dual-purpose batteries in your excursions. These batteries are meant to power both starting and cycling.

However, only use marine dual-purpose options if your boat is too small to accommodate two batteries. The strain of providing energy for all procedures makes these have shorter lifespans than their counterparts.

Different Categories of Batteries

When deciding on the correct battery to buy for your boat, it's also important to learn about the different categories available on the market.


These are popular choices among anglers because of their many advantages.

Wet-cell batteries (also called flooded-cell) contain battery acid, a mixture of sulfuric acid and distilled water. They have startlingly high amounts of discharge/recharge cycles. In fact, if maintained properly wet-cells can be recharged 1,000 times.

Additionally, the price of a wet-cell is similar to the cost of gel or AGM batteries, a boater's other two options.

However, wet-cell batteries do require regular inspections, venting and topping off with distilled water. They are also sensitive to vibrations and have higher chances of spills.


Absorbed Glass Mat (AGM) batteries have absorbent glass matting in between their plates which is soaked with acid electrolyte. The effect is a lot less maintenance. In fact, only periodic external cleaning is required of these power horses.

They also avoid spills due to the lack of vents on the battery itself and are vibrate-resistant.

Unfortunately, the low maintenance comes with a trade. This battery type cannot be refilled with water if the battery is overcharged. Additionally, they tend to cost more and are usually heavier.


Gel batteries include liquid electrolyte. The liquid is gelled with silicates.

Like AGMs, they are sealed to avoid spills and refills. In addition, they have long lives, are vibration-resistant, can withstand low temperatures and are maintenance-free.

The downside is gel batteries require particular types of charges and come at a hefty price.

Lithium Ion

The newest and most popular option at the moment is lithium ion technology. Lithium ion batteries are the lightest weight and most energy dense option available. Furthermore, they have a very low failure rate, large capacity to hold a charge, and are more eco-friendly than lead batteries. The batteries that we sell here at Lithium Battery Power are guaranteed for over 5,000 charge cycles.


After deciding which type of battery is right for you, it's time to look at the characteristics. If you're purchasing a cranking marine battery, take a look at the cold cranking amps (CCA).

CCA measures the current flow produced when starting your boat's engine. Specifically, it measures the amps produced at 0 degrees Fahrenheit for 30 seconds.

Marine cranking amps (MCA) measure the same thing except at 32 degrees Fahrenheit.

The rule is easy here: higher is better. Refer to your boat's manual to see the suggested CCA and MCA , and if possible, purchase higher.

Other Things to Consider When Shopping for Boat Battery

Battery Sizes

Take a look at the battery group. It's labeled as Group 24, 27, 31, etc. and refers to the battery's size. Match the size to your ship's dimensions to ensure it fits properly.

Keep in mind a smaller group number means a smaller and lighter battery. However, a smaller battery usually means you won't have as much staying power.


How long will your battery last and how many times can you recharge it? These are vital questions.

Always check the reserve capacity (RC) to determine how long your battery will last out on the water. It is a measurement (in minutes) of how long a battery will produce 25 amps at 80 degrees Fahrenheit before dying.

Likewise, read reviews and take a look at the recharges for life or ask the dealer about them, as sometimes they won't be specified.

Manufacture Date

Finally, take a look at the manufacturing date on the battery. Pick the most recent to get a few extra months out of your purchase.

You'll notice battery dates are labeled with a letter and number. These correlate to a month and year. "D2," for instance, refers to April of 2012.

Ask About Chargers

Always ask about the chargers that can be used with a battery. Some kinds require specific chargers because of the volts used. At times, a charger's volts may be too high, which damages the battery.

Additionally, it's best to have a charger that won't eat the battery power when it's not in use.

Make an Easy Choice

Right now, your mind is probably whirling with all the jargon it's just learned: RCs, CCAs, AGMs . . . The boating world is full of acronyms and terms when you're purchasing your first boat battery.

But we're here to make your choice easier.

Browse our batteries to find the perfect addition to your boat.

It's time to wave goodbye to the shore. . . . At least for a little while.