There are four main chemical types in marine batteries: lithium, gel cell, AGM (absorbed glass mat) and wet cell. While the lithium batteries are different from the others, all others are based on lead acid. In terms of purpose, there are three main categories: Starter, Deep Cycle, and Dual Purpose. With so many options available, choosing the right marine battery can be overwhelming.

But don't worry, we're here to guide you through the process. In the following sections, we'll break down the different types of marine batteries and give you the knowledge you need to make an informed decision before you embark on a battery purchase.

Naval battery categories

There are three main types of marine batteries: starter, deep cycle and dual purpose batteries. Each type is designed to perform a specific function.

Starter Battery: Marine starter/starter batteries are specifically designed to deliver a high burst of power to start the boat's engine. They feature a large number of thin sheets of lead that provide a large surface area for the chemical reactions to generate electricity. These batteries are not suitable for deep discharge cycles, but rather for short, high bursts of energy. Marine starter batteries are commonly used in boats that have a separate battery to start the engine and a separate battery to power accessories.

Deep Cycle: Deep Cycle marine batteries, on the other hand, are designed to provide a stable and reliable power source over an extended period of time. They are made of thicker lead plates which allow for a slower discharge rate and longer lifespan compared to starter batteries. Deep-cycle batteries are commonly used for trolling motors, avionics, and to power large electrical loads for long periods of time, such as overnight camping trips on a boat. These batteries are designed to withstand repeated and deep discharges without significant damage. Currently all Power Queen batteries are in deep cycle mode.

Dual Purpose: Dual purpose marine batteries are a combination of starter and deep cycle batteries. They are designed to provide both the high cranking power needed to start an engine and high cycle capability to run onboard accessories. Dual purpose batteries are designed with a balance between the thin starter battery plates and the thicker deep cycle plates. While they don't excel in cranking or deep cycle performance when compared to dedicated batteries, they offer a compromise for boats with limited battery space. Dual-purpose batteries are commonly used in smaller boats or applications where a single battery needs to perform both cranking and deep cycle duties.

Types of marine deep cycle batteries by chemistry

Due to their chemistry, different types of marine deep cycle batteries are available. Common types include lead-acid batteries and lithium (LiFePO4) batteries.

1. Lead-acid battery

Lead-acid batteries are the most commonly used type in marine applications. These batteries use a liquid electrolyte and come in a variety of styles such as: B as lead-acid batteries and AGM (Absorbed Glass Mat) batteries.

Lead-acid batteries are one of the oldest types of marine batteries and are made of lead plates and acid. Flooded lead-acid (FLA) batteries require regular water addition, making them less suitable for marine use. A major disadvantage of lead-acid batteries is their bulkiness and weight, with each battery weighing around 80 pounds. This makes them unwieldy and increases the weight of the boat. In addition, lead-acid batteries have the slowest charging time compared to other types.

AGM and Gel Lead Acid batteries offer some improvements over FLA batteries. They have a lower self-discharge rate and are leak-proof. However, they still have a low capacity-to-size ratio, meaning they don't offer as much performance for a compact size.

Despite these disadvantages, some people choose lead-acid batteries, especially FLA batteries, because of their affordability. However, the cheaper price is offset by the need for frequent battery changes. Most lead-acid marine batteries typically only last about 2 to 4 years.

2. Lithium marine battery

Another type of marine deep cycle battery is the lithium battery, which uses a different chemistry known as a lithium iron phosphate (LiFePO4) battery. This type of battery solves the problems that lead-acid batteries often face. LiFePO4 batteries are smaller, lighter and have a longer lifespan. They also charge faster.

Advantages of using lithium marine batteries

Lighter in weight

By switching to lithium marine batteries, you can reduce the weight of your boat battery by up to 70%.

A traditional 12V 100Ah lead-acid battery weighs around 60 to 70 pounds, while a Power Queen 12V 100Ah mini battery weighs only 19 pounds.


A key advantage of lithium batteries is that they are maintenance-free. Tired of adding water to your lead-acid battery? LiFePO4 batteries do not leak and require no maintenance, so you can spend more time enjoying your boating activities. In addition, lithium batteries provide constant performance even when partially discharged. This means your trolling motor and other gear will be working just as well at the end of the day as they did when it started.


Lead-acid batteries can be prone to internal short circuits, damage from temperature fluctuations, and various problems caused by incorrect charging methods. It is worth noting that lead-acid batteries do not have a built-in battery management system (BMS) that monitors their performance and provides additional protections.

On the other hand, LiFePO4 lithium batteries are equipped with BMS, which provides protection against short circuit, over voltage, over current, over discharge, over heat and even low temperature. This feature increases safety and ensures battery longevity.

100% depth of discharge

Depth of discharge (DOD) refers to the amount of a battery's capacity that has been used or discharged relative to its total capacity. It is typically expressed as a percentage. For example, a battery with a 50% DOD has discharged half of its total capacity.

DOD is an important consideration for battery users as it affects a battery's performance and lifespan. In general, lower discharge levels can lead to increased wear on the battery and shorten its overall service life. Batteries that are regularly discharged to a higher DOD may have a shorter lifespan than batteries that are discharged to a lower DOD.

In contrast to lead-acid batteries, lithium batteries can be discharged to less than 50%. Power Queen's LiFePO4 batteries have a depth of discharge (DOD) of up to 100% without being damaged.

This gives you more flexibility in using battery capacity without worrying about potential damage.

10 year lifespan

Lead-acid batteries typically last 3 to 5 years under normal usage conditions. However, their lifetime can be significantly reduced if they are frequently over-discharged or exposed to harsh conditions. Gel batteries may have a slightly longer lifespan compared to lead-acid batteries.

On the other hand, LiFePO4 batteries with the 4000-15000 life cycle have a lifespan of about 10 years or more with proper care and maintenance. They are designed to handle a greater number of charge and discharge cycles without significantly affecting their capacity. This makes them more durable and suitable for applications where frequent cycling is required, such as deep cycle marine battery applications.

If you think long-term, choosing a LiFePO4 battery is a worthwhile investment.

FAQs on marine batteries

1.Can use a ship battery in a car?

Yes, you can use a marine battery in a car, but that might not be the most ideal choice. Marine batteries are designed to power marine applications, such as powering trolling motors or powering electronics on boats. They are typically deep cycle batteries that can handle frequent charge and discharge cycles.

Car batteries, on the other hand, are designed to provide a high burst of power to start the engine and only provide limited power to the car's electrical systems. They are often referred to as starter batteries or starter batteries.

Although a marine battery can technically be used in a car, it may not be as effective at providing the power needed for continuous engine starting. Car batteries are specifically designed for reliable starting, so it is generally recommended to use a dedicated car battery for automotive applications.

2.Can I charge ship batteries with trickle chargers?

Yes, you can charge a ship's battery with trickle chargers. Float chargers are designed to deliver a small and steady flow of current to a battery that slowly charges the battery over time. They are commonly used to keep batteries charged during storage or when the batteries are not in use.

It is important to note, however, that trickle chargers are not recommended for rapidly charging fully discharged ship batteries. In such cases, it is better to use an appropriate charger with higher voltage and current ratings to ensure faster and more efficient charging.

If you are using a LiFePO4 lithium battery, learn how to charge a LiFePO4 battery.

3.Can I charge my ship's battery while it's still connected to the boat?

In general, it is recommended to disconnect any consumer or accessory from the battery before charging. This ensures that the charging process is not interrupted and allows for close monitoring of the charging progress.

Choose your deep cycle ship battery at Power Queen

Choosing the right marine battery is critical to providing reliable power to your boat. Do you notice that the performance of your ship's batteries is declining? It's time to replace a new battery. Check out Power Queen, we offer Class A LiFePO4 batteries with more than 4000 cycles. If you have any questions, please contact