How Long Will a 35AH Battery Run a Trolling Motor?

How Long Will a 35AH Battery Run a Trolling Motor?Welcome to our comprehensive guide that will help you understand the battery run time of a 35AH battery for a trolling motor. As a boat owner, you know that the battery is a crucial component of your trolling motor. It is the battery that powers the motor and determines how long you can stay on the water and enjoy your day out on the boat.

So, if you’re wondering how long a 35AH battery can run your trolling motor, this guide is for you. We’ll discuss factors that affect battery run time, how to calculate battery run time, and how to optimize the life of your battery. We’ll also explore battery upgrade options for those who need longer-lasting power.

Our goal is to equip you with the knowledge you need to make informed decisions about your battery capacity, so you can have a reliable and enjoyable boating experience. Let’s explore the essential information you need to know about 35AH batteries, trolling motors, and battery run time.

So, let’s get started!

Understanding Trolling Motors and Battery Capacity

When it comes to using a trolling motor, having the right battery capacity is crucial. Understanding battery capacity starts with knowing about the ampere-hour (AH) rating.

The AH rating refers to the amount of current a battery can provide over a specific period. For example, a 35AH battery can provide a constant current of 1 ampere for 35 hours, or 35 amperes for 1 hour.

The battery capacity you require depends on the type of trolling motor you use. There are typically two types of trolling motors: freshwater and saltwater. Saltwater trolling motors are more powerful and require a higher battery capacity compared to freshwater models.

It’s essential to choose a battery with enough capacity to handle the power demands of your trolling motor. If you have a larger boat, you may need a battery with a higher AH rating to ensure optimal trolling motor performance.

Table: Trolling Motor Battery Capacity

Trolling Motor Type Battery Capacity Required (AH)
Freshwater 30-50
Saltwater 70-100+

One way to determine the battery capacity you need is to check the manufacturer’s recommendations for your trolling motor. Some trolling motors may have a maximum amp draw or a suggested minimum battery capacity.

It’s important to note that battery capacity alone doesn’t determine the overall run time of a trolling motor. Other factors such as the efficiency of the trolling motor, the speed settings, and the weight of your boat can also affect battery performance.

Factors Affecting Battery Run Time

Several factors can impact the run time of a trolling motor battery. Understanding these factors can help you maximize the performance and efficiency of your motor while also extending your battery’s life.

Trolling Motor Efficiency

The efficiency of your trolling motor is a crucial factor that affects battery run time. A more efficient motor will consume less power, resulting in a longer battery life. To maximize efficiency, ensure that your motor is properly maintained and in good working condition. Clean the propeller and check for any signs of damage or wear and tear that could affect its performance.

Speed Settings

The speed settings you choose can also significantly impact your battery run time. Higher speed settings consume more power and drain your battery faster. To extend your battery life, use lower speed settings when possible, such as when cruising or fishing in calm waters. Reserve higher speed settings for when you need to quickly move your boat from one location to another or when fishing in areas with strong currents.

Boat Weight

Another significant factor that can impact your battery run time is the weight of your boat. Heavier boats require more power to move, which can result in faster battery depletion. To minimize the impact of boat weight on battery life, consider reducing the overall weight of your boat, such as by removing unnecessary equipment or supplies. Additionally, using a motor with a higher thrust rating can help compensate for the added weight and reduce the strain on your battery.

Table: Battery Run Time at Different Speed Settings

Speed Battery Run Time
Low (1-2 mph) 10-12 hours
Medium (3-4 mph) 6-8 hours
High (5-6 mph) 3-5 hours

By considering the factors above, you can maximize the run time of your 35AH battery and ensure optimal performance from your trolling motor. In the next section, we’ll explore how to calculate battery run time for your specific needs.

Calculating Battery Run Time for a 35AH Battery

Now that we understand the impact of trolling motor power consumption and different speed settings on battery performance, we can move on to calculating the run time for a 35AH battery. Knowing the run time will help you plan your boating trips and ensure that you have enough power to last.

To calculate the battery run time, you need to know the ampere draw of your trolling motor at different speeds. This information can usually be found in the owner’s manual or by contacting the manufacturer. Once you have this information, you can use the following formula:

Note: This formula is an estimate and assumes that the battery is fully charged and in good condition. Actual battery performance may vary depending on several factors, such as the weight of your boat, water and weather conditions, and battery maintenance.

Example Calculation

Let’s say you have a 35AH battery and a trolling motor with the following ampere draw at different speeds:

Speed (mph) Ampere Draw (A)
2 5
4 10
6 15

Using the formula above, we can calculate the estimated battery run time at each speed:

  • 2 mph: 35AH ÷ (5A × 0.5) = 14 hours
  • 4 mph: 35AH ÷ (10A × 0.5) = 7 hours
  • 6 mph: 35AH ÷ (15A × 0.5) = 4.6 hours

Keep in mind that this is just an estimate and actual battery performance may vary. It’s always a good idea to carry a backup battery or have a charging system on board to ensure you have enough power for your entire trip.

Optimizing Battery Life for Extended Run Time

Maximizing battery life is essential for extending the run time of your trolling motor. Proper battery maintenance and charging practices can go a long way in ensuring optimal battery performance. Follow these tips to optimize your battery life:

  • Battery Maintenance: Regularly check your battery for signs of wear and tear, such as cracks, leaks, or bulges. Clean the battery terminals with a wire brush to remove any corrosion. Avoid storing the battery in extreme temperatures or direct sunlight.
  • Trolling Motor Maintenance: Keep your trolling motor clean and free of debris. Lubricate the propeller shaft and other moving parts regularly. Check the trolling motor’s internal wiring for any frays or damage.
  • Charging Practices: Use a high-quality smart charger specifically designed for deep cycle batteries. Avoid overcharging or undercharging the battery, as both can damage the battery’s lifespan. Charge the battery after each use and store it at a full charge.

By implementing these strategies, you can ensure your battery will last longer and provide dependable power for your trolling motor. This will not only extend your battery run time but will also save you money in the long run by avoiding premature battery replacement.

Battery Upgrade Options for Longer Run Time

If you’re finding that the run time of a 35AH battery isn’t sufficient for your needs, there are a few battery upgrade options available to consider. These include upgrading to a battery with a higher AH rating or switching to a deep cycle battery.

Higher AH Rating Batteries

One option for upgrading your battery is to purchase one with a higher AH rating. This will increase the amount of power your battery can store and, as a result, extend the run time of your trolling motor. For example, upgrading to a 50AH battery will give you approximately 42% more run time compared to a 35AH battery.

Here’s a comparison table to give you an idea of the approximate run times for different AH batteries:

Battery AH Rating Approximate Run Time
35AH 2-3 hours
50AH 4-5 hours
100AH 8-10 hours

Keep in mind that upgrading to a battery with a higher AH rating will also increase its weight and cost, so it’s essential to make sure the battery is compatible with your trolling motor and boat before purchasing.

Deep Cycle Batteries

Another option is to switch to a deep cycle battery, specifically designed for extended run times. These batteries are built to discharge more slowly and are engineered to withstand deeper discharge cycles while maintaining their overall performance. They’re an excellent choice for individuals planning on using their trolling motor for extended periods.

Here’s an example of a deep cycle battery that could be suitable for trolling motor use:

  • Mighty Max Battery ML35-12 – 12V 35AH Deep Cycle Battery

This battery provides longer-lasting power and is maintenance-free, making it a cost-effective choice in the long run. However, keep in mind that deep cycle batteries are typically heavier and more expensive than regular marine batteries. Additionally, it’s essential to make sure the battery is compatible with your trolling motor and boat before purchasing.


Understanding the battery run time of a 35AH battery for a trolling motor is crucial for maximizing your boating experience. By considering the factors that affect battery performance, calculating run time, optimizing battery life, and exploring upgrade options, you can ensure a reliable and enjoyable time on the water.

Remember to take into account the efficiency of your trolling motor, speed settings, and the weight of your boat when calculating battery run time. Implementing proper battery maintenance and charging practices is also essential for optimal battery life.

Choosing the Right Battery Capacity

When choosing a battery for your trolling motor, it’s important to consider the demands of your specific boating needs. A 35AH battery may be sufficient for some boaters, while others may require a higher AH rating or a deep cycle battery for longer-lasting power.

Ultimately, the right battery capacity for your trolling motor will depend on various factors, including the size of your boat, the water conditions you’ll be navigating, and the length of time you’ll be spending on the water.

Maximizing Performance and Enjoyment

By understanding the basics of trolling motors and battery capacity, considering the factors that affect battery run time, and optimizing battery life, you can make the most of your boating experience. Whether you’re out for a day of fishing, leisurely cruising, or water sports, choosing the right battery for your trolling motor is crucial for maximizing performance and enjoyment.

So take the time to calculate your battery run time, implement proper maintenance practices, and explore upgrade options if necessary. By doing so, you can ensure that your boating experience is always reliable and enjoyable.

Richard Dodds

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