Naval vehicles rely heavily on batteries to power their various accessories and components. Without a reliable battery, the ship cannot easily anchor or sail through the water. When choosing a battery for your marine vehicle, it is important to understand the different types available and their differences. Two common types of marine batteries are the marine deep cycle and marine starter batteries. This article aims to highlight the differences between these two battery types.
Part 1: All about the Marine Deep Cycle Battery
A marine deep cycle battery is a type of battery specifically designed to provide a constant current output over a long period of time. It is designed to withstand deep and repeated discharges without rapid failure. The battery can be continuously discharged and then slowly recharged over a period of time, referred to as a discharge/charge cycle. This type of battery is typically used in deep-cycle applications that require constant and uninterrupted power supply. Examples of such applications are fishing boats, sailing boats and electric propulsion systems.
Types of Marine Deep Cycle Batteries
The marine deep cycle battery comes in a variety of types including liquid acid, sealed lead acid and lithium ion batteries. Each type has its pros and cons depending on intended use and budget.
1. Liquid-acid batteries
Liquid-acid batteries are a cost-effective option. Still, there are some downsides associated with this type of battery. First, they have the lowest C rating compared to the other types discussed, meaning they cannot handle rapid charging or discharging without damage.
In addition, they require a more sophisticated charger that can provide equalization to ensure they last as long as possible. Insufficient maintenance can lead to sulphation. These batteries must not be left in a partially discharged condition and should not be discharged below 50% of their rated capacity, meaning their usable energy is far less than their capacity.
Its orientation is also important, as immersion in water can result in the release of dangerous hydrogen chloride gas. They require continuous float charging even when not in use, and regular water topping up is important.
Finally, proper ventilation in the battery room is important to avoid explosions from hydrogen gas released during charging.
2.Sealed lead-acid batteries
Valve-regulated lead-acid batteries, also known as valve-regulated lead-acid batteries, require no maintenance and last longer than liquid-acid batteries.
There are some downsides to consider, however.
The main disadvantage of sealed lead-acid batteries is their limited deep discharge capability compared to liquid-acid batteries. They are not designed for deep cycle applications and can be damaged if discharged below a certain point. This means they may not be optimal for long sailing voyages or when using trolling motors that require a constant power supply for extended periods of time.
Another point is that sealed lead-acid batteries are more expensive than liquid-acid batteries and may not be within the budget of some users. Lithium-ion batteries are more expensive than both sealed and liquid-acid batteries, but offer the added benefit of higher energy density.
Finally, sealed lead-acid batteries can suffer from thermal runaway caused by excessive heat generation when charging or discharging the battery. Proper ventilation is required to prevent this from happening to remove heat from the battery case.
3. Lithium Ion Batteries
Lithium-ion batteries are becoming increasingly popular in the deep-cycle battery market due to their many advantages over conventional lead-acid batteries. Li-ion batteries typically offer higher energy density, longer life, and lighter weight compared to lead-acid batteries. Therefore, they are ideal for marine applications. However, it is important to note that currently only the lithium iron phosphate (LiFePO4) battery is approved for marine use.
Part 2: All About Marine Starter Batteries
Unlike the deep cycle battery, the marine starting battery is designed to deliver a rapid pulse of power to quickly start the marine vehicle engine. The battery can deliver a high current in a short time. As soon as the engine is running, the marine generator recharges the battery. Marine starting batteries come in different types, each suitable for different types of engines.
Types of marine starter batteries
There are two main varieties of marine starter batteries:
Liquid batteries: The most common type of marine starter batteries are liquid batteries, also known as wet batteries. They use lead-acid chemistry and require regular maintenance, with distilled water added intermittently to replenish water used from the cells during charging. Liquid batteries are typically less expensive than other types of marine batteries.
Absorbent Glass Mat (AGM) batteries: AGM batteries require no maintenance and have a longer lifespan than liquid batteries. They are equipped with a fiberglass mat that absorbs and holds the battery's acidic electrolyte. This eliminates the need to add water or monitor electrolyte levels. In addition, AGM batteries are resistant to vibration and can have a higher discharge rate than liquid batteries, making them an optimal option for high-performance boats. However, compared to liquid batteries, AGM batteries are a more expensive alternative.
Part 3: Differences between marine deep cycle and starter batteries
Marine deep-cycle batteries are designed to provide constant power to electrical components for extended periods of time. They are equipped with thicker, robust plates that can withstand repeated deep discharge cycles without damaging the battery. Deep cycle batteries are commonly used for electric motors, avionics and other applications that require a constant power source.
Marine starter batteries are designed to deliver high power for a short period of time to start an engine. They use thinner plates that can deliver high currents for a short period of time before quickly discharging.
Overall, the main difference between marine deep cycle and starter batteries is their construction and intended use. Deep-cycle batteries are designed to deliver constant power over an extended period of time, while starter batteries are designed to deliver a high-power pulse to start an engine or other high-demand applications.
Part 4: Common misconceptions about marine batteries
There are several misconceptions about marine batteries that can lead to the wrong battery type being selected. A common misconception is that any type of battery can be used for the marine vehicle. While some batteries can work for a period of time, they may not last long and may fail sooner than expected. Another misconception is assuming that marine starter batteries can be used interchangeably with deep cycle batteries. As already mentioned, the intended use is different, and therefore also the battery type. After all, choosing the most expensive battery with the highest performance specifications does not always guarantee good quality. Other factors such as durability, performance requirements and maintenance need to be considered.
Marine Deep Cycle and Starter Battery FAQs
1. Can I use a marine starting battery as a deep cycle battery?
It is not recommended to use a marine starting battery as a deep cycle battery. Starter batteries are designed to be discharged and recharged quickly, while deep-cycle batteries are designed to be discharged more slowly and recharged more slowly.
2. How long does a marine deep cycle battery last?
A traditional lead acid deep cycle battery can last around 3-5 years, while a LiFePO4 battery can be used for over 10 years.
3. Can I charge a marine battery while on the water?
Yes, you can charge a marine battery while on the water. Many boats have onboard chargers that can charge the battery while the boat is in use. Alternatively, you can use a portable charger or generator to recharge the battery.
After a thorough investigation of both battery types, we strongly recommend the use of lithium iron phosphate (LiFePO4) batteries if you require a deep cycle battery for your marine vehicle. LiFePO4 batteries are an excellent choice due to their unmatched efficiency, extended lifespan, and ability to handle deep-cycle applications.
At Power Queen we specialize in high quality LiFePO4 batteries for marine use. Our batteries are built to last and excel in the demanding marine environment. They feature a lightweight design, maintenance-free operation and premium performance. Let us help you meet your marine power needs by contacting us today to learn more about our quality marine batteries.