Can a Solar Panel Power a Trolling Motor?

Yes, you can use a solar panel to power your trolling motor. Assuming you have correctly connected the panel to the battery, you will get power from the sun.

That’s the concise answer. So, now that you know that charging your trolling motor using a solar panel is possible, the next logical step is to learn about the various factors that make it possible. Here’s a quick snapshot of what we will cover:

At a Glance:

1️⃣ Ensuring the solar panel’s output aligns with the trolling motor’s power demands is vital, which involves considering factors like battery capacity and sunlight exposure.

2️⃣ It’s critical to match the voltage and amperage of the solar panel with the requirements of the trolling motor when selecting a solar panel.

3️⃣ The size of the solar panel, its wattage, and voltage play significant roles in powering a trolling motor efficiently; therefore, it’s essential to consider these aspects when choosing the right solar panel.

Before you jump into researching how to connect solar to charge the battery, have a read through this article first. Let’s begin!

⚡ Powering a Trolling Motor Using Solar Panels

Solar Panel Output Requirements

When selecting the right solar panel for your boat, you need to consider the output requirements. The output of the solar panel mainly depends on factors such as battery capacity, power consumption, and sunlight exposure.

You need to ensure that the solar panel’s output is sufficient enough to meet the power demands of the motor without draining the battery too quickly.

12-volt solar panels are available from 10-180 watts and can be used to power a trolling motor if it meets the motor’s power requirements.

You’ll also need to think about how much solar energy the whole boat requires if you are using the solar setup for more than just the trolling motor.

Matching Solar Panel and Trolling Motor Specifications

Here are some factors I need to consider when matching the specs of a panel with a motor:

Voltage: The voltage of the solar panel should be equal to or higher than that of the trolling motor’s requirements. A 12-volt system is common for small to medium-sized trolling motors.
Amps: You need to check the amp requirements of the trolling motor and ensure the solar panel can produce enough amps in optimal sunlight conditions.
Power Output: It’s crucial to find a solar panel with an adequate power output, measured in watts, to the motor. For example, a motor rated at 200 watts should have a solar panel with a similar output. It is also possible to run a trolling motor without a battery by directly connecting the solar panel if its output matches the power demands of the motor.

Okay, now that we have checked off the voltage, Amps, and power output, let’s move on to what to be on the lookout for when buying a panel.

🎯 Selecting the Right Solar Panel

Factors to Consider

The size of the solar panel, the wattage, and the voltage all play a role in the efficiency and effectiveness of powering a trolling motor.

So, to find the perfect solar panel for your needs, you need to measure power requirements against the available space onboard.

Recommended Solar Panel Types and Sizes

I’ll use a hypothetical example to help visualize a setup. For a trolling motor setup, let’s go with either a 12v or 24v motor. So, depending on our hypothetical motor’s specs and the battery capacity some popular panel sizes I might consider are:

70-watt panel: suitable for smaller trolling motors, providing a good amount of solar energy for charging.
100-watt panel: more efficient and could support a more powerful trolling motor, achieving faster battery charging as well.
150-watt panel: a larger and more powerful panel providing enough energy to service a high-powered trolling motor.

I should note that a 6 to 12-watt solar panel is sufficient for maintaining a full charge when the boat is not in use. But, in order to power the motor while on the water, you’ll need a higher wattage panel, such as the ones listed above.

In conclusion, to select the right solar panel for our imaginary trolling motor, carefully assess the factors, take into account the motor’s power requirements, and choose from the variety of available panel types and sizes.

Remember that if you want to use the panel for additional things, like charging the boat battery using the solar panel, you will need to get one that accounts for the added power requirements.

🔋 Battery and Charging System

Technically you don’t actually need a battery to power your trolling motor if you have enough solar. But in reality, it’s not practical, so let’s take a look at batteries in more detail.

Battery Types and Capacities

There are several types of batteries that can be used for electric trolling motors. Here are the most common ones:

Lithium battery: These batteries are lightweight, have a longer cycle life, and provide consistent power output. However, they can be more expensive than other battery types.
AGM battery: Absorbent Glass Mat (AGM) batteries are spill-proof, and they have excellent resistance to vibration. They are also durable and can endure a high number of charge-discharge cycles.

🎓 Note: Deep-cycle marine batteries are specifically designed for continuous charge and discharge cycles and are well-suited for trolling motors. A popular choice is a 12V battery with a 75 (group 24) to 120 AH (group 31) capacity.

Charge Controller and Related Components

A charge controller is essential. It regulates the voltage and current coming from the solar panels to ensure that the battery does not overcharge or over-discharge, thus maintaining its health.

A blocking diode is also an important component, as it prevents the battery from discharging back into the solar panel at night or during cloudy days.

In case you need to convert the battery’s direct current (DC) power into alternating current (AC) for operating some appliances on your boat, an inverter is necessary.

Charging Time and Maintaining Battery Health

The time needed to charge depends on the solar panel’s power, the battery’s capacity, and the sun’s intensity. For example, a 12V 100 Watt or 150 Watt Solar Panel is generally recommended for efficient charging.

Solar charging systems are a great way to keep your trolling motor battery charged without using a generator or electrical outlet.

🎛️ Performance and Limitations

Maximizing Efficiency

A typical trolling motor requires around 10-20 amps to move a boat at medium speed, and this amperage requirement can increase in stronger winds. Therefore, the size of the solar panel is crucial to provide a stable energy source.

One overlooked element is the propeller. If you want to maximize efficiency, then get something designed for minimal current draw. Also, speed control is an essential factor, as a simple 5-position changeover switch can control the trolling motor’s speed effectively.

Run Time

A highly simplified way of calculating run time would be to use the following steps:

Motor Power Usage: The run time of your motor without solar input can be calculated by dividing your battery’s capacity (in Watt-hours) by the power your motor uses (in Watts). So if your battery capacity is B and your motor power usage is Pm, your run time (in hours) is B/Pm.
Solar Panel Power Production: If your solar panel produces a certain amount of power (Ps), this power can be subtracted from your motor’s power usage when the motor and panel are used simultaneously. This effectively extends your run time.

Using this simplified (and, to be honest, crude) approach, if your motor and solar panel are operating at the same time, your run time (in hours) would be B/(Pm – Ps).

If you only use the motor when the solar panel isn’t charging the battery (like at night), every hour of sunlight extends your run time by Ps/Pm hours.

To increase the run time, connect multiple solar panels in series to generate enough power. The trade-off is this solution will add extra weight to the boat and affect the motor’s performance.

📈 Popular Solutions and Brands

As someone who is passionate about boating and renewable energy, covering pre-built systems and solar kits is fascinating to me. Here are the ones that stick out:

Pre-built Systems

For those who want an easy option, several brands offer pre-built systems that come with solar panels, charge controllers, and all the necessary components to power a trolling motor.

Minn Kota is one of the most well-known brands in the trolling motor industry, and they offer a solar battery charger to keep your motor charged and ready for action.

With their battery chargers, positioning the solar panel directly onto your boat or nearby is made easy. It is essential to choose the correct size of the solar panel, paying attention to battery types like Group 27 or Group 31.

Remember to double the wattage of your trolling motor when choosing a solar panel size. This ensures that the panel provides sufficient power to meet the motor’s energy requirements.

Kits

If you prefer a more customizable solution, a solar panel kit could be perfect for you. These kits typically include the solar panels, charge controller, blocking diode, and often additional accessories to help you set up the system.

Always select a kit designed specifically for marine environments, taking into account the unique challenges of water, salt, and weather.

Popular solar panel brands for trolling motors include: Renogy, Newpowa, HQST.
When selecting a charge controller, look for models that offer features like battery monitoring, overcharging protection, and waterproofing if you plan to use your trolling motor in wet or harsh conditions.

🔑 Key Takeaways

To wrap up, it is possible to power your trolling motor directly from a solar panel. But it’s not all that practical, and supplementing with batteries is a better option. Here are the key takeaways:

1️⃣ Opting for suitable battery types and capacities, using charge controllers for regulation, and understanding charging time and methods to maintain battery health are significant aspects of setting up a solar power system.

2️⃣ To maximize performance and efficiency, it’s necessary to ensure an adequate solar panel size, maintain proper speed control, and understand how to calculate run time.

3️⃣ Consider pre-built systems or solar kits from reputable brands to make installation easier and allow for customization.

If you have another boat and want to know about powering more systems, then here’s how to hook the solar panel up to your boat’s battery.