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How to Choose the Right Battery for Your Trolling Motor

How to Choose the Right Battery for Your Trolling Motor

The battery is a critical element of your trolling motor system. A high-quality deep-cycle marine battery should always be your first choice.

Battery Recommendations

We suggest selecting a 12V deep cycle LiFePO4 lithium battery with at least a 100 amp hour rating (LiTime 12V 100Ah LiFePO4). The higher the amp-hour rating, the more run time you will receive. When using lithium batteries, you want to ensure the battery provides enough continuous discharge amperage to run the motor at its max amp draw. If you are having any issues with your trolling motor and you are using Lithium batteries, verify you have enough continuous amperage available for the motor to pull its max amp draw. The chart below shows the max amp draw by motor thrust.

 Trolling Motor Thrust/Model Required Continuous Discharge Amperage
30 lb. 30
40 lb., 45 lb. 42
50 lb., 55 lb. 50
70 lb. 42
80 lb. 56
101 lb. 46
Engine Mount 101 50
112 lb. 52
Engine Mount 160 116
E-drive 40
Talon Shallow Water Anchor 30
Raptor Shallow Water Anchor 70

Note: A starting battery is not suitable for use with an electric trolling motor.

Battery Types

For many years, the "traditional" (lead-acid, AGM) batteries are the most popular trolling motor batteries but if you’ve been in the market for new trolling motor batteries recently you may have noticed some changes to what’s available in the market. Lithium Iron Phosphate (LiFePO4) marine batteries are becoming a more common option for powering trolling motors, fish finders, and other accessories. You can learn more about What Are LiFePO4 Batteries & Why They Are the Best in our recent blog.

If you plan to keep your boat and trolling motor system long-term, LiFePO4 Lithium could prove to be a smart investment. With up to 10-year wlife span the total cost of ownership may come out to be a wash vs. re-buying flooded batteries in the same time period.

Anyway, our choice will depend on your budget, your installation specifications, and your priorities. 

Lead Acid 

Lead acid batteries are the most affordable option. Depending on quality, lead acid batteries will last between 2-3 years. The downside of lead acid batteries is that they require occasional maintenance – topping off the water – and they are also prone to vibration and spillage.

AGM Batteries

AGM (Absorbed Glass Mat) Batteries are a type of lead acid battery that is completely sealed, generally, last longer on a charge, and typically has a longer life span. While a traditional deep-cycle battery might last approximately 2-3 years, an AGM deep-cycle battery can last up to three or four years. AGM's cost more than standard lead acid wet-cell batteries – up to 2x more – and may not be an option for those on a tight budget. 

LiFePO4 Lithium Batteries

Lithium batteries are starting to become more and more popular for a variety of reasons:

  • Extremely Lightweight - For smaller boats and boats where weight can be a considerable factor, lithium batteries offer a 70% average reduction in weight compared to traditional batteries.
  • Significantly Longer Battery Life - LiFePO4 Lithium batteries can last up to 10 years whereas lead acid wet-cell and AGM batteries have an average life span of 2-4 years. Even though there is a higher up-front cost for lithium batteries, they can save you money in the long run. If you calculate the cost of replacing your batteries every 2-3 years as opposed to every 10 years with lithium, you'll most likely be spending less on batteries.
  • 100% Depth of Discharge - This essentially means that you'll have full power regardless of the level of charge.
  • More Power - Due to the consistent, sudden fluctuation in speeds, trolling motors require a fair amount of cranking torque (aka thrust). Lithium batteries supply more power due to their negligible voltage drop when rapid acceleration is required.
  • Smaller size: Not only are lithium batteries lighter, but they also take up less space, which means a lot for boats.

It’s important to note that no matter what battery type you choose, you’ll want to make sure you find a “deep cycle” battery. This will be clearly labeled and all it really means is that the battery was designed for using smaller amounts of energy over longer periods of time. LiTime LiFePO4 lithium batteries are all deep cycle batteries that half the wight of traditional batteries while 4 times the energy. Choose from LiTime 12V series LiFePO4 lithium battery for your trolling motors

“Deep Cycle” isn’t terminology you will always find when shopping for Lithium marine batteries, but essentially all LiFePO4 batteries are designed to operate this way.

How Long Does a LiFePO4 Battery Last on a Trolling Motor?

It depends. Every battery and trolling motor is slightly different, and there are many different variables that may influence how long your battery is going to last.

Because of these variables, the same battery may run your trolling motor for a given amount of time on one boating trip and for a completely different amount of time on another trip.

Here are some factors that may impact the run time of a liFEPO4 lithium battery on a Trolling Motor:

Amp Hours

One of the most important numbers when figuring lithium battery run time is the amp hours, or Ah. It shows the amount of amperage the battery could supply over a given time period. How long the battery lasts depends on how many amps your trolling motor is consistently drawing from the battery. The lower the amp draw, the longer the battery will last.

Battery Size

If you buy a small battery to fit in your kayak, for example, it isn’t going to give you as much run time as a larger battery would. That said, a kayak-sized trolling motor will probably draw less power from the battery, which may increase its charge life.

Battery Type

There are four main types of marine batteries: lead-acid, AGM, gel, and LiFePO4 lithium. Of these types, lithium batteries generally last the longest while lead-acid batteries typically need more frequent recharging.

Battery Life Span

Regardless of the type of battery, it will lose its ability to hold a charge over time. Older batteries tend to develop internal resistance that makes them more difficult to charge, and when in use, they may discharge more quickly.

If you have an older battery, you can expect that it won’t last as long as it did when it was newer. The problem will only get worse, so it may be a good idea to keep a battery charger on board your boat, just in case the battery dies sooner than you’re expecting.

LiTime LiFePO4 lithium batteries has more than 10 years life span which saves you big over time.

Maintenance

Some battery types require more maintenance than others, but all types should be properly cleaned and cared for between uses. LiTime LiFePO4 lithium batteries are maintenance-free, however, there is still something that should take attention.

See also: Things You Should Know When Using LiFePO4 Batteries

Weather Conditions

Operating your trolling motor in extreme temperatures, high winds, and choppy waters will force your battery to work harder, thus causing it to discharge faster. 

 

Boat Size

A larger, heavier boat will take more power to push through the water than a small, lightweight boat. More draw on the battery will lead to a quicker discharge.

If you have a larger boat, it’s a good idea to invest in a battery with a higher amp hour rating. A large boat will be able to support the additional size and weight, and you’ll be able to spend more time out on the water, doing what you love.

Usage

If you are using a single battery for more than just your trolling motor, it will discharge more quickly because multiple sources will be drawing from it.

For example, if you’re running your trolling motor and fishfinder off the same battery, neither device will last as long as it would on its own. Both are drawing from the battery simultaneously, so the battery will run out of power sooner than it would power only one device.

Finding the right batteries for your fishing boat can be a tough task, but when armed with the right information it doesn’t have to be. 

Additional Battery Tips

Never mix battery types or old batteries with new batteries. 

Charge batteries as soon as possible after each use – leaving batteries in a discharged state will decrease their longevity and performance.

Store batteries in a cool, dry place in the off-season and maintain a trickle charge.