[Comprehensive Guide] Types of Marine Battery

Marine batteries play a vital role in powering various electronic devices and equipment on boats, from small recreational vessels to larger fishing boats and houseboats. Unlike automotive batteries, marine batteries have unique features and requirements due to the diverse power demands they must meet.

This article aims to provide a comprehensive guide to marine batteries.

The Feature of Marine Battery

The role of automotive batteries is to provide enough power to start the engine, especially in cold weather. In order to do so, the battery needs to supply a large amount of current within a few seconds. After the engine is started, the alternator takes over to power all electronic devices in the car and recharge the battery.

Marine batteries typically have different requirements. Your marine engine still requires a battery to start, but the battery may also need to meet many other power needs. In smaller recreational boats, the marine battery also needs to power lights, gauges, pumps, and other electronic devices. On the other hand, fishing boats and houseboats may require multiple types of batteries to operate household systems or motors.

3 Different Types of Marine Battery Based on Usage Methods

There are 3 different types of marine batteries, starting battery, deep-cycle and dual purpose battery.

1.Starting Battery

Marine starting batteries are designed to provide a high burst of power to start the boat's engine. They deliver a quick surge of energy required for engine ignition. These batteries are typically rated by Cold Cranking Amps (CCA), which indicates their ability to start an engine in cold conditions. Marine starting batteries have a large number of thin plates, which provide a high surface area for increased power output during engine cranking.

2.Deep-Cycle Battery

Deep-cycle batteries, on the other hand, are designed to provide a steady amount of power over a longer period of time. They are used to power accessories and equipment on boats, such as trolling motors, radio systems, and lights. Currently, all of Redodo's LiFePO4 batteries are deep cycle. 

Deep-cycle batteries are able to withstand repeated deep discharges and recharges without significantly affecting their performance and lifespan. They are typically rated by Ampere-hours (Ah), which represents the battery's capacity to deliver a steady current over a specified time period.

3.Dual-Purpose Batteries

Dual-purpose batteries are a combination of starting and deep-cycle batteries. They are designed to provide both the high starting power required for the boat's engine and the sustained power needed for accessories. These batteries offer a balance between the two types and are suitable for boats that require both starting power and auxiliary power.

2 Different Types of Marine Battery Based on Conducting Medium Inside

Boat batteries can be classified based on the chemistry or conducting medium inside them. These classifications include lead acid batteries like flooded lead acid, AGM (Absorbed Glass Mat), Gel, and lithium (LiFePO4) battery.

1. Lead Acid Battery

Flooded lead-acid batteries are the most basic type, consisting of a sulfuric acid solution with lead plates suspended in it. These batteries require regular monitoring and the addition of water to maintain their proper operation. On the other hand, absorbent glass mat batteries, also known as sealed lead-acid batteries, are sealed and do not require the same level of maintenance as FLA batteries. AGM batteries also contain lead plates, but they are positioned between fiberglass sheets saturated with electrolyte.

Pros

• Cost-effective: Lead acid batteries are generally more affordable compared to other battery types.
• High surge currents: They have the ability to deliver high surge currents, making them suitable for applications that require brief bursts of high-power, such as starting boat engines.

Cons

• Low energy density: Lead acid batteries have a relatively low energy density compared to other battery types such as lithium-ion. On average, lead acid batteries offer around 30-40 watt-hours per kilogram (Wh/kg), while lithium-ion batteries can provide around 150-200 Wh/kg.
• Limited cycle life: Lead acid batteries have a limited number of charge-discharge cycles. On average, they can withstand 300-500 cycles before their capacity starts to diminish significantly. This is a crucial factor to consider for applications that require frequent cycling.
• Ventilation requirements: Lead acid batteries release hydrogen gas during charging, which can be potentially hazardous if not properly ventilated. This can be a concern for confined spaces like boat cabins, as proper ventilation needs to be ensured to prevent the accumulation of explosive gases.
• Acid leakage risk: There is a chance of acid leakage from lead acid batteries due to improper handling, damage, or defects. This can be corrosive and harmful to the environment, requiring caution and maintenance to prevent leaks.
• Regular maintenance requirements: Lead acid batteries require regular maintenance to ensure their optimal performance and longevity. This includes monitoring electrolyte levels, maintaining proper charging voltage, equalizing charges periodically, and cleaning terminals to prevent corrosion buildup.

2.Lithium marine battery

Lithium iron phosphate (LiFePO4) batteries are a specific type of lithium-ion deep-cycle battery used in marine applications. Lithium-ion deep-cycle batteries are a modern alternative to traditional lead-acid batteries. Instead of using sulfuric acid and lead plates, they utilize lithium salts to store energy. Although they are currently the most expensive option in the deep-cycle battery market, their numerous advantages make them a popular choice for boating applications.

Pros

• Higher Energy Density:Lithium batteries have a higher energy density compared to lead-acid batteries. This means they can store more energy in a smaller and lighter package, making them more suitable for applications where weight and space are limited.
• Longer Cycle Life:Lithium batteries have a longer cycle life compared to lead-acid batteries. They can endure more charge and discharge cycles before experiencing a significant decrease in capacity. This can result in a longer overall lifespan for the battery. The Redodo LiFePO4 batteries have 4000+ life cycle, which can be used for more than 10 years.

• Fast Recharge Capability:Lithium batteries can be recharged at a faster rate compared to lead-acid batteries. Their ability to accept a high charge current allows for quicker charging times, reducing the downtime between uses.
• Maintenance-Free:Lithium batteries require minimal maintenance. Unlike lead-acid batteries that need regular topping up with distilled water and equalization charging, lithium batteries do not have these requirements. This can save time and effort in servicing and maintaining the battery.
• Lightweight:Lithium batteries are significantly lighter than lead-acid batteries. The weight reduction can be especially beneficial for marine applications, where every pound matters and can contribute to better performance and fuel efficiency. A Redodo 12V 100Ah Mini weights only 19lbs but has 1280 Wh energy.
• Voltage Stability: Lithium batteries maintain a more stable output voltage throughout their discharge cycle, delivering consistent power until they reach their cutoff voltage. This can be advantageous for devices that require a stable power supply.

Cons

The biggest drawbacks of lithium-ion marine batteries is their higher initial cost.

FAQs about Marine Battery

1.What battery is recommended for a boat?

For most cases, 12V batteries is the appropriate choice.

2.Can I use a regular car battery as a marine battery?

While a regular car battery can technically function as a marine battery, it is not the optimal choice. Marine batteries are specifically designed to withstand the unique demands of marine environments, including vibration, moisture, and extended periods of deep cycling.

Conclusion

Selecting the optimal boat battery depends on your specific needs and application. In instances where deep cycling is necessary, a lithium-ion marine battery is the superior choice due to its efficiency, reliability, overall cost, and weight. However, if you require a starting battery, a lead-acid battery may be more suitable.

Whether you're engaging in recreational boating, fishing, or living on a houseboat, it is crucial to choose the right battery for your requirements. By considering your specific application and understanding the advantages of different options, you can make an informed decision and select the best marine battery for your needs.