Boat Batteries: Choosing The Best For Your Vessel

Choosing the right battery for your boat is essential to ensure optimal performance and avoid unnecessary costs. There are several factors to consider when selecting a boat battery, including size, weight, power, and budget. Here are some of the best boat batteries available in the market:

- Lithium-Ion Batteries: These batteries offer multiple features, such as Bluetooth, Wi-Fi, and Cellular connectivity. They have a long lifespan and a low self-discharge rate, making them ideal for both deep cycle and engine-starting applications.

- AGM Batteries: Absorbed Glass Mat (AGM) batteries are versatile and suitable for marine use. They hold their charge better than wet and gel cell batteries, making them excellent dual-purpose options.

- Optima Blue Top: This battery is known for its durability and performance. It can be mounted in almost any position and is resistant to vibration. It has a smaller footprint than comparable batteries, making it ideal for boats with limited space.

- Interstate Deep Cycle Batteries: These batteries have proven wet cell construction and are widely available through marine dealers, tackle stores, and automotive shops. They offer numerous configurations to fit different needs.

- Deka Marine Master: This lead acid deep cycle battery is easy to install and offers plenty of reserve capacity. It comes in sizes 24, 27, and 31 and features molded-in offset posts, stainless steel studs, and wing nuts.

- Dakota Lithium: These lightweight batteries are perfect for kayaks and small boats. They offer up to 80% capacity for 2,000 cycles and can withstand extreme temperatures.

- Amped Outdoors 36V 50Ah Trolling Motor Lithium: This battery offers extreme longevity and Bluetooth monitoring capabilities. It is the lightest in its class and provides extended range for kayak anglers.

- Pro-Guide AGM: These batteries offer excellent value for money and can be discharged 500 times without significant power loss. They are available in sizes 24, 27, and 31 and come with a 24-month replacement warranty.

- Bass Pro Shops Power Series Deep-Cycle AGM Marine Battery: This dual-purpose battery can be used for both cranking and deep cycle purposes. It is maintenance-free, vibration-resistant, and offers good power and performance.

- Newport Bluetooth Lithium Battery: This high-tech lithium battery offers easy-to-use app integration and a battery management system. It provides peace of mind and ensures you have enough power for your accessories.

Choosing the right battery for your boat

There are four different chemical types of marine batteries for your boat: wet cell (flooded), gel cell, absorbed glass mat (AGM)—which are all lead-acid batteries—and lithium. The type you choose is based on your needs (engine starting versus deep cycle), the capacity and lifespan you are looking for, and your budget.

The most versatile type for marine use is the AGM battery. If you don’t use your vessel daily, AGMs will hold their charge better than wet and gel cell batteries. Long lifespan and low self-discharge rate make AGM excellent dual-purpose (deep cycle and engine starting) batteries for boats.

Lithium batteries are also a good option. They are more expensive, but they are also lighter and more compact than lead-acid batteries. Lithium batteries can do more with less weight than ever before and maintain their strength for more cycles.

For all batteries onboard, stick with one battery chemistry (e.g. AGM). Each battery type requires specific charging voltages, and mixing types can cause under- or over-charging.

When choosing a battery, consider your budget, the weight of the battery, and how often you will be using your boat.

Battery maintenance

To maintain a marine battery, keep the connections clean, fully charge it, and keep your battery box dry with good ventilation.

Correctly Wiring Your Boat

Batteries are the primary part of a vessel’s electrical system, so it is crucial to look after your marine battery. Dealers and experts always recommend using standard batteries because they are designed to withstand challenging water and weather conditions. However, purchasing and installing a battery on your boat is not enough. You must follow a routine boat maintenance and repair schedule and act whenever required.

Charging and Discharging

One process you can do is charge and discharge the boat’s battery properly. Remember not to overcharge it as it can affect the lifespan. Also, using all the charges regularly can create issues later. While not in use, you can store the battery in a cool, dry place to maintain its condition for extended periods.

Once you have selected the correct battery type with the help of a professional, you need to create a handy checklist to ensure a longer lifespan. Inspect the connections and terminals regularly to identify any corrosion. Keep the battery clean and free of any dust or debris. Always wear gloves when you work around batteries to keep your hands safe from acid. Also, stick with one type of battery once the boat dealer recommends it. Using different types of batteries can lead to underperformance of your boat electronics and shorten the lifespan of the battery bank.

Charging Practices

Avoid overcharging. Don’t use all of its charges regularly. Both these cases will harm the battery life and performance. Read and follow the manufacturer’s instructions for proper charging. Keep the area around the battery ventilated, especially during charging. It will help you maintain the battery’s condition.

Turning Off

Turn off the battery master switch when you leave the vessel. When you are not using your boat for longer, disconnect the batteries and store them in a cool, dry place to avoid unnecessary problems.

Battery types: marine, lithium, lead-acid, etc

There are four different chemical types of marine batteries for your boat: wet cell (flooded), gel cell, absorbed glass mat (AGM), which are all lead-acid batteries, and lithium. The type you choose is based on your needs (engine starting versus deep cycle), the capacity and lifespan you are looking for, and your budget.

Wet Cell (Flooded)

Wet cell marine batteries are commonly used in starting applications. This battery has a no-spill design and can be tilted to a 45° angle, making it perfect for marine use. They are the least expensive of marine batteries and do a good job as long as you never drain them below 50% capacity. They require a little extra work, but given proper maintenance, they reliably get the job done. However, these batteries are bulky, have a life expectancy of just two to three years, require off-season recharging and occasional topping-off of the fuel cells with distilled water. They are heavy (an average 100-Ah lead acid battery weighs between 60 and 80 pounds), more fragile than competing formats, and may not hold up well in a high-vibration environment. Lastly, they charge more slowly compared to other battery options.

Gel Cell

Gel cell batteries are a type of FLA battery. They are fully sealed so there’s no need to top them off, and they don't leak. They have a slower discharge rate than the original FLA format. However, they are heavy and bulky, with a limited lifespan.

Absorbed Glass Mat (AGM)

Sealed, valve-regulated AGM batteries feature fine, highly porous microfiber glass separators compressed tightly between the battery's positive and negative plates, which are saturated with just enough acid electrolyte to activate the battery. They have a low self-discharge rate and outstanding performance, making AGM batteries excellent dual-purpose batteries for boaters who require the fastest recharging, quick starting power and reliable deep cycle ability.

Lithium

Lithium batteries are smaller, lighter, long-lasting, and faster charging than lead-acid batteries. You can shed up to 70% battery weight off your boat just by using lithium marine batteries. They are also safer and don't require any maintenance. Boaters will love the fact that they provide the same output at 100% charged as 50% charged. Unlike lead-acid batteries, you can discharge your lithium batteries past 50% without damaging them.

Battery weight and size

When it comes to choosing the right boat battery, weight and size are important factors to consider. The weight and size of a battery can impact the performance, range, and manoeuvrability of your boat.

Lithium batteries are a popular choice for boat owners as they are lighter and more compact than traditional lead-acid batteries. This can be a significant advantage, especially for small boats like kayaks and canoes, where a heavy lead battery can take up valuable space and compromise manoeuvrability. Lithium batteries also have a longer lifespan and a lower self-discharge rate, making them a good choice for boats that are not used daily.

However, lithium batteries come with a higher price tag, and some boaters may be hesitant to switch due to fire risk concerns. Additionally, lithium batteries should not be used as starter batteries, and some engine manufacturers do not honour warranties if lithium is used for this purpose.

For those looking for a more affordable option, lead-acid batteries are still a viable choice. The "Flooded" or "Wet Cell" battery is the most common type of lead-acid battery. They are usually more cost-effective than other types, but they require maintenance in the form of topping up with water and can be heavy and cumbersome.

When choosing a boat battery, it's essential to consider your specific needs, budget, and the type of boat you have. The weight and size of the battery can significantly impact your boating experience, so it's crucial to select one that fits your requirements without compromising performance or safety.

Battery charging

Charging your boat's batteries is essential for keeping them in good condition and ensuring they last a long time. Here are some tips for charging your boat batteries:

• Use the right charger for your battery type: Different types of batteries require different chargers. Using the wrong charger can damage your battery or undercharge it.
• Keep your batteries charged: Boat batteries tend to lose their charge over time, so it's important to keep them charged, especially when they're not in use. Consider using solar, wind, or water power to trickle charge your batteries.
• Check water levels for wet cell batteries: If you have wet cell batteries, regularly check the water levels and top them off with distilled water as needed. Fill them up after charging, as water levels tend to drop during charging.
• Disconnect batteries when not in use: To prevent battery drain, always disconnect your batteries when your boat is not in use.
• Perform seasonal maintenance: At the beginning of the boating season, charge and check your batteries for connection and corrosion issues. At the end of the season, remove the batteries for storage, clean the top surfaces, grease terminal bolts, and store them in a dry, cool area.
• Use a battery management system: Some lithium batteries come with a Battery Management System (BMS) that helps regulate and protect the charging and discharging of the battery cells. This can help extend the life of your battery.
• Consider a dual battery setup: If you have a dual battery setup, with one battery for starting and another for accessories, make sure to keep them separate and only connect them when necessary.
• Don't mix old and new batteries: In a battery bank, avoid mixing old and new batteries, as the old batteries can pull down the new ones to their deteriorated level.
• Keep connections clean: Regularly clean the connections on your batteries to ensure optimal performance.

Frequently asked questions