There are four main chemical types of marine batteries: lithium, gel cell, AGM (absorbed glass mat) and wet cell. While lithium batteries are different from the others, all others are lead acid based. In terms of intended use, 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 will break down the different types of marine batteries and give you the knowledge you need to make an informed decision before embarking on your battery purchasing journey.

Categories of marine batteries

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 provide a high burst of power to start the boat engine. They have a large number of thin lead plates 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 starting batteries are commonly used in boats that have a separate battery for starting the engine and a separate battery for powering 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 a longer lifespan compared to starter batteries. Deep-cycle batteries are commonly used for trolling motors, onboard electronics, and powering large electrical loads for extended 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: Marine batteries with dual purpose are a combination of starting and deep cycle batteries. They are intended to provide both the high cranking power required to start an engine and high cycling capability for operating on-board accessories. Dual-purpose batteries are designed with a balance between the thin starter battery plates and the thicker deep-cycle plates. Although they do not outperform dedicated batteries in either starting or deep cycle performance, 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 handle both starting and deep-cycle duties.

Types of Marine Deep Cycle Batteries by Chemistry

There are different types of marine deep cycle batteries available based on their chemistry. 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 are available in different versions, such as: b as lead-acid batteries and AGM batteries (absorbed glass mat).

Lead-acid batteries are one of the oldest types of marine batteries and are made of lead plates and acid. Flooded lead-acid batteries (FLA) require regular addition of water, making them less suitable for use at sea. 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. Additionally, 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 power 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 replacement. Most lead-acid marine batteries typically only last about 2 to 4 years.

2. Lithium marine battery

Another type of deep cycle marine battery is the lithium battery, which uses a different chemistry known as lithium iron phosphate battery (LiFePO4). 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.

Benefits 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 standard 12V 100Ah lead-acid battery weighs about 60 to 70 pounds, while a Power Queen 12V 100Ah mini battery weighs only 19 pounds.

Maintenance-free

A key advantage of lithium batteries is that they require no maintenance. Are you tired of adding water to your lead acid battery? LiFePO4 batteries do not leak and require no maintenance, allowing you to spend more time enjoying your boating activities. In addition, lithium batteries deliver consistent performance even when partially discharged. This means that your trolling motor and other equipment will work just as well at the end of the day as it did at the beginning.

Security

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

On the other hand, LiFePO4 lithium batteries are equipped with a BMS that provides protection against short circuits, over-voltage, over-current, over-discharge, overheating and even low temperatures. 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 DOD of 50% has discharged half of its total capacity.

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

Unlike 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 damage.

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

10 year lifespan

Lead-acid batteries typically last 3 to 5 years under normal usage conditions. However, their lifespan can be significantly shortened if they are frequently deeply 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 life cycle 4000-15000 have a lifespan of about 10 years or more with proper care and maintenance. They are designed to handle a larger 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.

Marine Battery FAQs

1.Can I use a marine battery in a car?

Yes, you can use a marine battery in a car, but that may 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 deliver a high burst of power to start the engine and 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 required to continuously start the engine. Car batteries are specifically designed to provide reliable starting, so it is generally recommended to use a dedicated car battery for automotive applications.

2.Can I charge marine batteries with trickle chargers?

Yes, you can charge a marine battery using trickle chargers. Trickle chargers are designed to provide a low and continuous flow of current to a battery, slowly charging the battery over time. They are commonly used to maintain the charge of batteries while in storage or when the batteries are not in use.

However, it is important to note that trickle chargers are not recommended for quickly charging completely discharged marine batteries. In such cases, it is better to use a suitable charger with higher voltage and current ratings to ensure faster and more efficient charging.

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

3.Can I charge my marine battery while it is still connected to the boat?

In general, it is recommended to disconnect all consumers or accessories from the battery before charging. This ensures that the charging process is not interrupted and allows accurate monitoring of the charging progress.

Choose your deep cycle marine battery at Power Queen

Choosing the right marine battery is crucial to reliably powering your boat. Are you noticing that the performance of your marine batteries is decreasing? 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 service.de@ipowerqueen.com.