Best Trolling Motor Battery & How To Choose The Right Type

The choice does not have to be a difficult one when selecting the best trolling motor battery. However, many anglers don’t give their batteries too much thought… until they fail. And nothing cuts a day of fishing short like a dead trolling motor.

It is quite common that a fishing day is cut short or, even worse, an angler leaves a tournament early due to equipment problems. Good batteries are a necessity, and there are several types of batteries to choose from.

Wet-Cell Batteries

Wet-cell batteries are also known as deep cycle marine batteries. Trolling motor batteries are meant to take some punishment. Batteries will be charged and drained constantly, and a deep-cycle marine battery is meant to stand up to those type of conditions. These batteries usually last between 1 year and 2 ½ years, depending on use and how they are stored. They are relatively inexpensive, which is why many anglers choose them.

Don’t confuse these batteries with a cranking battery. A cranking batteries have a number of thin lead plates in them and are meant to give short bursts of energy for a fast start. Deep-cycle marine batteries, on the other hand, have thicker lead plates and are meant to provide you with power over a long period of time. The thicker plate in deep-cycle marine batteries also stand up to the higher temperatures that are created by a constant current draw that last a long period of time.

AGM Batteries

AGM trolling motor batteries are also known as gel-based batteries. AGM stands for Absorbed Glass Mat. These batteries are built using a glass plate and a gel-like substance. These batteries tend to last a bit longer than their wet-cell counterparts. The useful life for an AGM battery is usually between 3 and 4 years. While they can cost up to twice as much as a wet –cell deep-cycle marine battery, they are the best value for longevity as well as for performance over a longer period of time.

AGM batteries are “maintenance free” batteries. This means they are enclosed, and you will not have to open them up to add distilled water as you would with a wet-cell battery. These batteries will offer more battery capacity in less space. So, if space is a bit of an issue in your boat, checking the dimensions of an AGM battery versus a wet-cell trolling motor battery might be a good idea. High quality AGM batteries will also hold their charge longer when not being used. Their self-discharge rate is much lower than with wet-cells.

Some anglers choose AGM batteries simply because they are sealed and many are not fond of the idea o having liquid battery acid in their boat. If you are undecided whether to spend the extra money for an AGM battery, keep these things in mind. Also, most of the time, the warranty on an AGM trolling motor battery will be longer than on a wet-cell battery.

Lithium-ion Batteries

Lithium-ion batteries are relative newcomers to the market. They are being used by many pro fishermen today, who speak very highly of them. The biggest issue for the weekend angler or amateur tournament fisherman will most likely be the cost. These batteries are expensive. You can plan to spend $850 to $1,500 easily per battery.

One of the great things about the Lithium-ion battery is the life expectancy. These batteries will last about 10 years if kept under 105 degrees. Very high temperatures may reduce the battery’s life expectancy somewhat regardless if you purchased the best battery for trolling motor or not.

Amperage Hours

Trolling motor batteries, and all other batteries, are rated by Amperage Hours, commonly abbreviated Ah. While this may seem confusing, it is really just a measure of how long your battery will run your trolling motor while its drawing a certain number of amps. It is usually best to go with the highest rating you can afford and that will fit in your boat. If, for instance, you have a 12-volt trolling motor, you will definitely want a battery with the highest amperage hour rating you can use. Because you only have one battery, you want to make sure that you can run your trolling motor as long as possible without draining the battery.

Here is an easy calculation for amperage hours: For example, you havea battery rated at 100 Ah. If you are running your trolling motor on low speed and it is pulling 4 amps, the battery should last 25 hours: 100 / 4 = 25 . If your trolling motor pulls 40 amps on high, your battery will last for 2.5 hours: 100/40 = 2.5. Looking at these calculations, it is easy to see why a higher Ah rated battery is preferable.

Battery Chargers

Just as important as the battery itself is the charging system an angler uses. It is not uncommon for an angler with a heavy boat to use a 36-Volt trolling motor. While the Lithium-ion batteries do offer a 36-volt version, the typical angler will have a wet-cell or AGM set-up. This means there will be three trolling motor batteries to charge. That can make it difficult to use a typical battery charger such as the one you may charge a car battery with.

Also, if you are charging your batteries away from home, you not only have to remember to bring your charger, but you will have to do whatever you can to make sure it is not stolen while sitting in a parking lot behind a hotel or what have you.

For most anglers, a much better option is to have an onboard charger mounted in the boat itself. Onboard chargers are made by a wide variety of companies and offer different amps of charge per bank. While that is a topic for another day, suffice it to say that these chargers, if there is available room, are a much better option for most anglers. Simply plug an extension cord into the charger, and a trickle charge will be delivered directly to your batteries, charging them all up at the same time.

These chargers will keep a charge on all of your batteries while you are not using your boat as long as you leave them plugged in. This will keep the batteries fully charged and ready to hit the water any time you are ready.

When you purchase your onboard charger, it will come with instructions on the procedure for hooking up your batteries. It may also have a selector switch allowing you to select a wet-cell or AGM battery. Make sure to select the proper type of battery and, if you have more than one battery, to hook them up as the wiring diagram shows.

Battery Care Tips

Even the best of batteries will not perform to their specifications if they are not properly care for. Here are some tips to help your batteries last as long as possible:

  • Keep them charged. As soon as you return from the lake, get the charger on your batteries and keep them full. Batteries can get a type of “memory”, and if they are left partially charged more often than they are full, they will tend to drain to that point more quickly.
  • Use a trickle charge. A slow and steady charge, like that from most onboard chargers, is actually better for your batteries than a heavy, fast charge. This will not heat up the plates in a typical battery as much, allowing the battery to last longer.
  • Store them properly. During the off-season, store your batteries in a cool, dry place and, if possible, keep a trickle charge on them.
  • Never mix types of batteries, or use old and new batteries together.
  • If you’re using wet-cell batteries, check them from time to time and top them off with distilled water if necessary. Do not use tap water in batteries – only distilled water.
  • When you’re in the battery compartment hooking up the charger, or maybe each time you put gas in the boat, check the battery terminals. Tie checking the terminals into another activity that you do: gassing the boat, adding oil, etc. That way you won’t forget to check the terminals. If they are looking bad, disconnect the battery cables and clean the terminals up with a baking soda and water paste. Dry them well and reconnect the cables. Using a battery post spray on the terminals can help reduce the build up that you might see on the terminals.

Trolling Motor Battery Reviews

Think about the type of fishing you do, the punishment you expect your batteries to take, your budget, and the space you have available, and that will help you to select the perfect battery for trolling motor for your application.

These select trolling motor battery reviews are our goto units when powering our boats or kayaks.

Odyssey 34M-PCST Trolling Thunder Marine Dual Purpose Battery

This is an AGM battery. With 880 cold cranking amps, this battery is a dual purpose powerhouse. It will set you back around $400, but it is tolerant to even the most extreme temperatures. The useful life of this battery is between 3 and 10 years, which makes it more affordable over the long haul. The design of this battery also helps protect it against the impact of going over heavy waves as well as the vibration that is present in a typical marine setting.

Minn Kota Trolling Motor Power Center

The name Minn Kota has been synonymous with quality trolling motors for many years. This power center is built specifically to house a trolling motor battery and offer the user easy access to connecting leads to the terminals. Battery boxes such as this are required by the Coast Guard, so why not purchase one that is deigned to fit a 24- or 27-Group size battery, and also has an external 12-volt accessory plug? This is a great addition to any trolling motor battery compartment.

VMAX857 AGM Battery 12V 35A Marine Deep Cycle Hi Performance Battery

This little battery is perfect for smaller 12-volt trolling motors with from 18- to 35-lb thrust ratings. And it’s priced very well at just over $100. It offers maintenance free operation and is built to take the punishment of repeated charging and discharging. For smaller trolling motors and boats, this battery might be just the perfect choice.

Might Max Battery 12V 55AH Power Boat Pontoon Electric Trolling Motor Deep Cycle Battery

This is a wet-cell lead acid battery with an amperage hour rating of 55. It boasts long lasting performance in a very wide temperature range, for those who might be using the trolling motor in extreme heat or extreme cold. It’s compact size allow it to be used even where space is an issue. It is a great choice for light to moderate use on a smaller trolling motor. It is also very affordable, at just over $100.

Optima Batteries 8016-103-FFP D34M Blue Top Starting and Deep Cycle Battery

Optima batteries are fairly new to the scene and have become a favorite of many anglers who put their trolling motor batteries through some extreme and tough conditions. This particular battery offers 750 cold cranking amps, to get you up and running, even in the most extreme weather conditions. These batteries are a bit more expensive, but if an angler deals out tournament-style punishment to trolling motor batteries, the extra expense will definitely be worth having batteries that can take anything the tournament hands them.

Smart Battery 12V 100Ah Deep Cycle / Starting Lithium Ion Battery

For the “normal” angler, the price of Li batteries, going well over $1,000 may be too much to fathom. However, for the hard-core tournament angler who is looking to save weight and space, Lithium-ion batteries are becoming much more popular. This particular battery has a 1000 amp cold cranking rating and will last over 5,000 cycles of charging and discharging. It is about 70% lighter than a lead battery of the same capacity and is 99.1% efficient. Again, this is not a battery for the typical weekend angler, but Lithium ion batteries have come a long way since their inception, and many pros are turning to these as a great power option.

Overall, the battery you choose will be determined by a variety of factors. Whether you opt for a wet-cell, an AGM, or even a Lithium battery, a little research on what is the best trolling motor battery will go a long way toward having more successful days on the water.