Battery Costs For Boaters: How Much Do They Drain?

The cost of a battery for a boat depends on the type of battery and its specifications. There are three main types of boat batteries: starting batteries, deep-cycle batteries, and dual-purpose batteries. Starting batteries provide a short burst of power to start the boat motor, while deep-cycle batteries can be drained slowly over long periods. Dual-purpose batteries combine the benefits of both starting and deep-cycle batteries. The price of boat batteries can vary from around $100 to $500 or more, depending on the brand, type, and features. For example, lithium-ion deep-cycle batteries, which are known for their efficiency and long lifespan, tend to be more expensive than lead-acid batteries. When choosing a boat battery, it's important to consider factors such as efficiency, reliability, lifespan, and weight, as these will impact your boating experience and maintenance requirements.

Starting vs. deep cycle marine batteries

The cost of a battery for a boat varies depending on the type, brand, and specifications. On Amazon, prices range from $69.99 to $499.99 for a single marine battery.

Now, let's discuss the two main types of marine batteries: starting batteries and deep-cycle batteries.

Starting Batteries:

Starting batteries, also known as cranking batteries or marine engine start batteries, are designed to provide the quick burst of powerful energy needed to start a boat's engine. They are engineered to deliver high cranking amps (CA) and cold-cranking amps (CCA) for reliable engine ignition. Cranking amps refer to the battery's ability to deliver power at 32°F (0°C) for 30 seconds, while cold-cranking amps measure the maximum power delivery at 0°F (-18°C), which is crucial for cold weather starting. Starting batteries have several thin plates, maximising the plate surface area to facilitate the delivery of the necessary power to start the engine.

Deep-Cycle Batteries:

Deep-cycle marine batteries, on the other hand, provide a steady and sustained power output over an extended period, making them ideal for applications that require continuous power. They are used to power electrical systems and appliances like sonar, GPS, radios, refrigerators, and trolling motors. Deep-cycle batteries have fewer but thicker plates, allowing them to withstand repetitive deep discharging and recharging without damage. They can be entirely drained and recharged frequently, and they are less prone to overheating due to their thicker plate construction.

In summary, starting batteries are essential for quickly cranking the engine, while deep-cycle batteries keep the boat's electronics and accessories running smoothly during operation. While some dual-purpose batteries can serve both functions, it is generally recommended to use separate starting and deep-cycle batteries for optimal performance, especially for larger boats with more powerful engines and extensive electronics.

Multi-purpose boat batteries

When it comes to boating, having a reliable and versatile battery is crucial. Multi-purpose boat batteries, also known as dual-purpose batteries, offer a great combination of starting power and deep cycle capabilities, making them an excellent choice for various boating needs. These batteries can be used for both starting your boat's engine and powering essential equipment on board.

There are different types of dual-purpose batteries available on the market, each offering unique advantages:

Lead Acid Dual-Purpose Batteries

Lead-acid batteries are a common option for boaters. They are known for their fast recharging capabilities and long service life. Lead-acid dual-purpose batteries can be further categorised into two types:

• Flooded Lead-Acid: These batteries are the most common type. They feature cells submerged in a liquid electrolyte, making them ideal for starting purposes.
• AGM (Absorbed Glass Mat): AGM batteries utilise a fiberglass mat to suspend the electrolyte, resulting in enhanced power, durability, and maintenance-free operation.

Lithium Dual-Purpose Batteries

Lithium dual-purpose batteries are another excellent option for boaters. While they may have a higher upfront cost, their long lifespan, efficiency, and reliability make them a cost-effective choice in the long run. Lithium batteries offer both engine-starting power and deep-cycle capabilities, making them versatile and suitable for a wide range of boating applications.

Cost of Multi-Purpose Boat Batteries

The cost of multi-purpose boat batteries can vary depending on the brand, type, and specifications. Here are some examples of prices for dual-purpose batteries from different brands:

• Duracell Ultra: The Duracell Ultra BCI Group 24M 12V 550CCA Flooded Dual-Purpose Marine & RV Battery is priced at $119.99.
• X2Power: The X2Power BCI Group 31M 12V 100AH 1150CCA AGM Deep Cycle Marine & RV Battery is available for $499.99.
• Optima: The Optima High-Performance D34M BlueTop Dual-Purpose Battery is a sealed AGM battery offering both starting and deep cycle functions. It is priced at $179.99.
• Weize: The Weize Deep Cycle AGM 12 Volt 100Ah Battery, perfect for marine use, is available for $179.99.
• Renogy: The Renogy Deep Cycle AGM 12 Volt 100Ah Battery is another excellent option for marine use, priced at $175.77.

It's important to note that prices may vary across different retailers and online stores, so it's always a good idea to shop around and compare prices before making a purchase. Additionally, some batteries may have additional costs, such as core deposits, which are refunded upon the return of a used battery.

Battery weight

The weight of a battery for a boat depends on the type of battery, its capacity, and its intended use.

Marine Battery Weights

Marine batteries are available in different group sizes, which refer to their physical dimensions (length, width, and height). The most common sizes are Group 24, Group 27, Group 31, Group 34, and 8D batteries. The weight of these batteries can vary depending on the type of battery, such as lead-acid or lithium.

A standard 100 Ah lead-acid battery typically weighs between 60 and 80 pounds. On the other hand, a lithium battery with the same capacity is significantly lighter, weighing about half as much as its lead-acid counterpart. For example, a Dragonfly Energy 100 Ah lithium battery weighs approximately 31 pounds.

Deep Cycle Battery Weights

Deep cycle batteries are used in cycling applications such as trolling motors and floor scrubbers. They come in various types, including flooded lead-acid, AGM (Absorbent Glass Mat), and lithium. The weight of a deep cycle battery depends on its capacity and type.

For instance, a 105 Ah deep cycle battery is described as very heavy, while a 50 Ah battery is considered a smaller capacity option. A 50 Ah wheelchair battery weighs around 30 pounds and can be a suitable alternative for powering a small inflatable pontoon boat for a day's fishing.

Trolling Motor Battery Weights

Trolling motor batteries are designed to power electric outboard motors on boats. They are available in different voltages, such as 12V, 24V, 36V, and 48V. The weight of a trolling motor battery depends on its capacity and voltage requirements.

A 12V 100 Ah lithium trolling motor battery can weigh as little as 16.5 pounds, making it an ultralight option for kayak fishing and starting smaller outboard motors. In contrast, a 12V 100 Ah lead-acid battery can weigh significantly more, typically in the range of 60 to 80 pounds.

When choosing a battery for a boat, weight is an important consideration. Reducing the weight carried on a boat is crucial, as all vessels have weight limits. Lighter batteries, such as lithium-ion batteries, offer several advantages, including increased efficiency, improved performance, and enhanced safety.

Additionally, lithium batteries provide a significant weight reduction compared to lead-acid batteries, especially when considering the total weight of multiple batteries. For example, if a boat requires six lead-acid batteries, switching to lithium batteries would result in a weight reduction of almost four times, assuming each lithium battery weighs half as much as its lead-acid equivalent.

Therefore, when considering battery weight, it is essential to take into account the capacity, type, and intended use of the battery, as these factors will determine the most suitable option for your boat.

Battery lifespan

The lifespan of a boat battery depends on several factors, including the type of battery, usage, maintenance, and environmental conditions. On average, a marine battery can last between three and seven years, but this can vary significantly depending on how well it is maintained.

One of the most critical aspects of extending battery lifespan is proper maintenance. This includes regularly monitoring the battery's state of charge and avoiding discharging it below 50% of its rated capacity. Over-discharging is the leading cause of battery failure, and allowing the battery to reach a completely flat state can destroy it within a few months. Therefore, it is recommended to charge the battery before the voltage falls below 12.2V, which indicates a 50% charge.

Calculating your daily power usage is another essential factor in ensuring optimal battery life. If your batteries are too small for your power requirements, you will be drawing too much charge each day, reducing the lifespan of the battery. Ideally, the service batteries should have an amp-hour (Ah) rating that is three times larger than the boat's daily electrical consumption.

Reducing your power requirements can also help extend battery life. Simple measures such as turning off unnecessary lights, using low-energy LED bulbs, and ensuring adequate insulation for the fridge can significantly reduce power consumption.

Additionally, it is crucial to protect your battery from the elements. Batteries can be vulnerable to heat, so storing them in a cool, dry place can help prolong their lifespan. Keeping the battery box or compartment well-ventilated is also essential, as gases escaping from the battery, especially when overcharged, can be explosive.

Proper charging practices are also vital for maintaining battery lifespan. Both overcharging and undercharging can reduce the battery's lifespan and degrade its performance. Using a smart marine battery charger designed for permanent installation can help maintain optimal charge levels and prevent overcharging.

Furthermore, it is recommended to stick with one battery type for your boat. Mixing different types of batteries can lead to overcharging or undercharging, which will shorten the overall lifespan of your battery bank.

In summary, by following these guidelines and implementing proper maintenance practices, you can significantly extend the lifespan of your boat batteries, ensuring they provide reliable power for several years.

Battery maintenance

The cost of a boat battery varies depending on the type, brand, and specifications. Deep-cycle batteries, for example, can be recharged and discharged multiple times without sustaining damage and are a popular choice for trolling motors. On the other hand, gel and lead-acid batteries are known for their durability and affordability. If faster charging and higher energy density are priorities, lithium-ion batteries are an option, albeit a more expensive one.

Selecting the Right Battery:

Consult a professional to choose the correct battery type for your boat, taking into account factors such as usage and boat type. Deep-cycle batteries, for instance, are suitable for trolling motors as they can provide a steady power supply for extended periods.

Routine Maintenance:

Develop a checklist to ensure the longevity of your battery. Regularly inspect connections and terminals for any signs of corrosion, and keep the battery clean and free of dust and debris. Always wear gloves when handling batteries to protect your hands from acid.

Charging Practices:

Avoid overcharging your battery, as this can negatively impact its lifespan and performance. Follow the manufacturer's instructions for proper charging, and ensure the area around the battery is well-ventilated during the charging process.

Storage:

When your boat is not in use for extended periods, disconnect the batteries and store them in a cool, dry place. Turn off the battery master switch to prevent unnecessary issues.

Standard Batteries:

Dealers and experts recommend using standard batteries designed to withstand challenging water and weather conditions. While non-standard batteries may be tempting to save money, they may not hold up as well under heavy use.

Accessories:

Consider using accessories designed to improve your battery connection and extend its life. For example, PulseTech's Marine Solargizer uses Pulse Technology to emit a pulsating DC current, helping to re-energize the battery and remove lead sulfate deposits.

Electrolyte Levels:

Before charging, check the electrolyte or water level in the battery and ensure it is filled to the manufacturer's recommendations. Do not overfill, as battery gases are highly explosive. Keep flames, sparks, and smoking materials away from the battery when filling or working around it.

Charging Routine:

Charge your batteries as soon as possible after a fishing trip or outing. The longer a battery stays discharged, the shorter its lifespan will be due to lead sulfate buildup on the plates.

Terminal Cleaning:

If you are not using a specialized connector, clean the battery terminals every three months as recommended by manufacturers.

Connection Tightness:

Regularly check all connections for tightness to ensure optimal performance and avoid loose connections, which can cause issues.

Frequently asked questions