How Long Will a 100Ah Battery Run a 55lb Trolling Motor?

Trolling motors provide quiet and efficient propulsion, making them ideal for fishing or leisurely cruising. Among the popular options is the 55lb trolling motor, which offers a good balance between power and maneuverability. But how long will a 100Ah battery run this motor? Let’s dive into the details in this article.

Understanding Trolling Motor Power and Battery Capacity

Before we dive into the question, it’s essential to understand how both battery capacity and motor power consumption work.

Trolling Motor Power

Trolling motor power refers to the amount of thrust or force that the motor can generate to propel a boat through the water. This is typically measured in pounds of thrust, with higher numbers indicating greater power.

In a 55lb trolling motor, the "55lb" refers to the motor’s thrust, and 55 pounds is a moderate power rating suitable for small to medium-sized boats, like kayaks or jon boats.

Battery Capacity

A battery rated at 100Ah (Amp-hours) can theoretically provide 1 amp of current for 100 hours or 100 amps for 1 hour. How long the battery will last depends on the motor’s power draw.

Battery capacity refers to the amount of energy that a battery can store. In the context of trolling motors, this is important because the motor is powered by a battery. The capacity of the battery determines how long the trolling motor can run before needing to be recharged. This is typically measured in amp-hours (Ah), with higher numbers indicating greater capacity.

How Much Power Does a 55lb Trolling Motor Use?

On average, a 55lb trolling motor at full speed consumes between 40 to 55 amps per hour, depending on the brand and efficiency. To calculate how long your battery will run your motor, use this simple formula:

Run Time (Hours) = Battery Capacity (Ah) / Motor Current Draw (Amps)

The current draw of a trolling motor varies depending on the speed setting and the load it is carrying. To provide an estimate, let's assume that your 55lb trolling motor draws 50 amps at full throttle and your battery is a 12V 100Ah trolling motor battery. The calculation would be:

100Ah / 50A = 2 hours

So, if you’re running your motor at full power, a 100Ah battery will last around 2 hours.

However, it’s important to note that most people won’t run their trolling motor at full speed all the time. If you run it at 50% power, the motor might draw only 20-25 amps, which would extend your battery life to around 4-5 hours.

• Full speed: Running at full throttle may give you 2 hours of battery life on a 100Ah battery.
• 50% speed: If you cut the speed in half, you could extend that run time to 4-5 hours.
• 25% speed: At even lower speeds, like 25% throttle, the motor might only draw 10-12 amps, potentially stretching the battery to last 8-10 hours or more.

What Factors Can Affect Battery Run Time?

While the formula above gives a rough estimate, several factors can affect how long your 100Ah battery will power your 55lb trolling motor:

1. Boat Weight and Size: The size and weight of your boat are among the most critical factors affecting the power draw of a trolling motor. Heavier boats require more power to move, which increases the motor’s current draw.
2. Water Conditions: Rough water or strong currents will force your motor to work harder, draining the battery faster. Planning your trips based on weather and water conditions can help conserve power.
3. Speed Setting: Lower speeds reduce the motor’s power consumption, allowing the battery to last longer. Using lower speeds during routine cruising or fishing, and reserving higher speeds for short bursts, will help extend battery life.
4. Battery Type: The type of battery you use (e.g., AGM or LiFePO4) can influence efficiency and usable capacity. Opting for a lithium battery can significantly extend the time your motor runs, especially during longer trips.
5. Battery Age and Health: The age and health of your battery also play a role in determining how long it can power your trolling motor. Over time, batteries lose capacity, which reduces their running time.

Maximizing Your Affordable Trolling Motor

Choosing an affordable trolling motor doesn’t mean you have to sacrifice performance or efficiency. To get the most out of your 55lb thrust trolling motor and extend battery life, consider these tips:

• Invest in a LiFePO4 Battery: Lithium-ion batteries, such as LiFePO4 batteries, offer greater efficiency and longer run times compared to traditional lead-acid batteries. They also have a higher usable capacity, meaning you can discharge them deeper without damaging the battery.
• Use a Battery Monitor: Install a battery monitor to keep track of the remaining charge and optimize how you use your trolling motor during your trips. You can also keep track of the battery's remaining power, voltage, current and other real-time information with the battery monitor. Learn More: What is A Battery Monitor?
• Balance Throttle Use: Running your motor at a lower speed will conserve power and extend your time on the water. Additionally, using a lower throttle setting improves control and maneuverability, especially in tight spaces or when fishing near vegetation.

Is a 100Ah Battery Enough for a 55lb Trolling Motor?

For most anglers, a 100Ah trolling motor battery provides sufficient power for a full day on the water, especially when used with a 55lb trolling motor at moderate speeds. However, if you plan to use your trolling motor extensively or for multiple days without recharging, you might want to consider investing in a second battery or upgrading to a higher-capacity battery such as LiFePO4 battery.

With a remarkable usable capacity of 101Ah-105Ah at 100%DOD, the Redodo 12V 100Ah Marine Lithium Battery surpasses traditional 12V 100Ah AGM batteries (with a 50% DOD) by delivering twice the runtime. What’s more, the battery sheds a whopping 40 pounds in weight, which greatly increases the speed of the boat.

Conclusion

In summary, a 100Ah battery can run a 55lb trolling motor for about 2 hours at full speed or 4-5 hours at moderate speeds, making it an excellent choice for most boating and fishing activities. However, various factors such as boat weight, water conditions, and battery type can influence the actual run time. By choosing an affordable trolling motor and optimizing your battery setup, you can enjoy longer, more productive trips on the water.

For those looking to maximize their time on the water, consider upgrading to a LiFePO4 battery or investing in a high-quality battery monitor for better power management.

Related Reading: How Long Do Marine Batteries Last & Tips To Maintain