Have you noticed how solar panels have advanced in recent years? Arguably, technological improvements have created opportunities to break away from the conventional designs and applications of solar chargers. One of the creative applications you may have heard of is the use of solar in trolling motors – but can you depend on it?
You can use solar panels for your electric trolling motor. To do so, attach a 12v or 24v panel to the battery pack. Besides, a 6 to 12-watt panel can maintain your fully charged battery when not using the boat. However, always use a charge controller and blocking diode to protect your battery.
You don’t have to spend each time you need to recharge your trolling battery. Solar energy is evidence that this statement is true. Read on for a comprehensive discussion on why you need a charge controller, the benefits of using solar energy, how to charge your motor using solar, and why it’s still impossible to power trolling motors using sunlight directly.
Note: most links in this article are Amazon.com Affiliate links, see Affiliate Disclosure, thank you.
Do I Need a Solar Charge Controller?
Regardless of the method you use to charge a battery, it’s always critical to regulate the current coming from the source to avoid damage by overcharging. Most 24 volt solar panels put out 32 to 45 volts, while a standard battery needs 14 to 14.5 volts to get fully charged. Because of that, it would be better to use a charge controller.
Generally, you can use two criteria to determine if you need a charge controller. The first method is to check the panel output; if it puts out 2 watts of below for each 50 battery amp-hour, you won’t need one. The second approach is to divide the battery amp-hour by the panel’s highest power amp rating.
If you use the second method and the quotient is 200 and above, you won’t need a controller. However, if the answer is less than 200, you’ll need one.
Tip: Your batteries may discharge backward through the panels. It would be better to have a blocking diode to prevent that.
Can I Charge My Trolling Motor On Solar?
Let’s cut to the chase: yes, you can successfully charge your trolling motor on solar.
You can do that by attaching a 12v or 24v panel to the trolling motor’s battery pack. In most instances, a small, 6 to 12 – watt panel can maintain a fully charged battery pack while you’re not using the boat.
As long as there’s no parasitic loading, a low-wattage solar panel with a daily output of 750 mA to 5 Amps can keep your battery pack topped off for future use. If your battery pack releases parasitic loading, it’s advisable to use a panel with double the output I’ve mentioned within the same period. Most notably, the panel should put out at least 4 Amps daily if the parasitic draw is 2 Amps every 24 hours.
The Downsides (and Things to Consider)
Besides keeping your fully charged battery topped off and maintained, you can use solar panels to charge them once they’re fully discharged, although doing that comes with limitations.
The wattage of panels tends to increase with size. However, most boats come with insufficient space for mounting solar panels.
Most manufacturers typically recommend that customers use group 27 – 31 batteries often, complicating the issue further. Most notably, they expect that you’ll discharge the battery to about 50% per session, meaning the panel should make up for around 50 – 65 Amps at that level.
Although most customers don’t care how long it takes for batteries to recharge, experts, recommend charging them as quickly as possible. This is because if you don’t recharge a battery for a long time, the lead sulfate inside them crystallizes through a process called sulfation, reducing the battery’s lifespan.
You can easily prevent sulfation. If you’re using a battery that ranges from 75 to 120 amp-hours (group 24 – group 31), you should use a 12v, 70-watt panel at a minimum. Ideally, it would be best if you used a 100-watt panel or a 150-watt panel (the assumption here is that they’re all 12v panels). The typical daily output of the 70-watt panel, in this case, is 16 – 24 Amps, while that of the 100-watt is 20 – 31 Amps, and that of the 150-watt panel is 32 – 48 Amp.
From these outputs, it’s quite obvious that it will take longer to charge a battery with the lower wattage panels completely. The larger panel can do it within a shorter time, making it the ideal solution for back-to-back usage of trolling motors.
Suppose you have a 24v trolling motor battery. In that case, it becomes even more difficult to recharge the battery pack using solar. If you’re using a group 27 – 31 battery, you should use a panel twice the wattages of the 12v panels I’ve mentioned. For example, at least, you should use a 24v, 140-watt panel and, at most, a 24v, 300-watt panel.
Boat solar panels series or parallel: which type of connection can you use?
Like most power installations, you can connect boat solar panels in series or parallel; to double the wattage of a 12v panel, connect it with another one in series.
Reasons To Charge Your Trolling Motor Using Solar
What are the benefits of using solar panels on trolling motors? This is a question customers often ask, and I’ll highlight why you should use solar to charge your trolling motor using solar panels:
Solar panels use natural sunlight as a source of energy, making them friendly to the environment. Unlike gas-powered or portable generators that require you to carry some fuel when going out trolling, you don’t have to weigh your boat down by carrying the extra load. There’s a high chance that the fuel you’ll need to use these alternatives to panels is harmful to the environment.
Solar Is Renewable Energy
Investing in a boat solar panel kit is a sure-fire way of gaining access to a virtually unlimited energy supply. Your panels capture the endless supply of energy – you won’t need to run any gas engines or plug into local utilities. You just need boat solar panel mounts and to place the panel where it’s directly exposed to sunlight.
In a nutshell, you get a natural and free energy source. This saves you money in the short and long term.
Tip: Some boat solar system kits can work even in low light conditions. Ensure you read the manufacturer’s specifications to identify the best panel to buy.
Solar Guarantees Peace and Quiet
When at sea, nothing is as therapeutic as the strange sounds and sensations and the view of marine life.
Loud noises from your backup generator and the outboard engine can sometimes upset the comforting experience. However, with solar energy, you can have a relaxed, noise-free experience at sea.
A Boat Solar Installation Reduces Your Workload
Suppose you don’t have an onboard charging system. In that case, I guess you usually remove your batteries after each fishing excursion to recharge them. Right?
That happens because you use a substantial amount of electric power while trolling, meaning your batteries get depleted quickly. However, with a solar-recharging setup, you don’t need to do that after having a great day at sea!
With sunlight, the batteries begin to recharge as you fish and become fully charged by the time you return home, especially if you’ve spent the better part of your day on the water. Besides, most solar panels come with in-built charge controllers and blocking diodes that prevent overcharging and discharging, respectively. Consequently, they increase your batteries’ durability.
What To Look For in a Boat Solar Panel
There are several types of trolling motor chargers on the market, each with its pros and cons. When choosing panels for your trolling motor, it’s essential to do research to determine the ones most suitable to your needs.
Here are a few things to consider:
The Charger Type
There are three main types of solar-powered battery chargers.
- If you’re looking for efficient, durable, corrosion-resistant, and high output chargers, you should pick polycrystalline panels. These panels have high transmission glasses and come with silicon crystal construction, giving them a distinctive blue color.
- The second type, the monocrystalline panel, offers higher energy efficiency and performs better even in low light conditions. These panel types have a distinctive black color.
- The third type, thin films, come with in-built semiconductors, increasing efficiency. They are narrow in design and absorb less light.
When spending your hard-earned cash on a panel, you should be guaranteed some form of protection if the product turns out defective, and a warranty is one of the ways a manufacturer will ensure that.
I recommend that you buy solar battery chargers with longer warranty periods.
Power and Charge Controller
When considering this aspect, look for the wattage ratings of the available panels. Ideally, you should pick chargers with ratings of 100 watts and above.
Also, ensure the panel comes with a charge controller. I’ve previously described the significance of this critical device – you wouldn’t want to damage your battery!
As I mentioned earlier, sulfation can damage your battery. However, you can reverse it by buying a panel that’s designed to desulfate batteries, prolonging their durability.
To learn more about sulfation, I suggest that you watch this video by Skill Lync:
For efficient charging, pick a charger that matches the battery type.
Although I’ve previously discussed this aspect, let me reiterate it: ensure the panel’s voltage and wattage match your battery’s group.
Is It Rigid or Flexible?
Rigid solar chargers are what you’d consider traditional or conventional solar panels. Most of them are designed to be mounted in one place, although you could get some foldable, portable options. To install them, you need a racking system.
Instead of a rigid panel, you should buy a flexible panel. These boat flexible solar panels are designed to be installed on different surfaces. They are lighter than traditional solar chargers, making them ideal for boats. They require boat solar panel mounts that can be angled to maximize the amount of sunlight they receive.
There are several products you can use for panel mounting. The most notable ones are glue and bolts. If you choose glue, ensure you either clean the surface before bonding or sand it, depending on the adhesive type.
You could also use bolts. Suppose you go on deep-sea fishing excursions. In that case, you need a mount that can hold the panels in place even during stormy weather, and bolts do the job better than glues and adhesives!
How To Charge My Trolling Motor on Solar
To charge a trolling motor using sunlight, you first need to have a boat solar panel setup ready.
These are general steps to follow when installing solar chargers for your trolling motor:
- Mount the panel on your boat, preferably on top of the main cabin.
- Attach 2 sets of marine-grade copper wires (black and red) to the solar panel).
- Run the wires into your boat’s main cabin.
- Attach the wires to the solar charger’s controller.
- Attach another set of similar marine-grade wires from the controller to the battery, with the positive on the positive terminal and the negative on the negative terminal.
For an overview of how the components should be connected, you can refer to this boat solar wiring diagram from Pinterest:
Now relax and let the sun do its magic!
Can I Run My Trolling Motor on Solar?
Unfortunately, the idea of powering trolling motors is still far-fetched.
In stable weather, a standard motor would require 10 amps to move a boat at medium speed, while the requirement would increase to 20 amps in stronger winds.
To use solar to power a motor without a battery, you would need several high-end panels, which is impractical. In fact, it raises more questions than answers:
Where would you get the space to mount several panels on your boat?
Why would you need to break the bank to acquire high-end boat solar system kits when you can use the cheaper alternative – batteries?
Besides, for the boat solar panel to deliver the required energy, you’ll need to expose it to unobstructed sunlight, which must hit the surface at a right angle for maximum efficiency. However, that could be impractical on a cloudy day, at night, and when nearby trees or cables provide a shade cover to the panel.
As it stands, the practical approach is to buy a charger that converts the sun’s energy to a form you can use to power your trolling motor, and that’s what panels are built to do!
With a panel, you can charge your battery at your convenience – whether on or off the boat.
In a nutshell, we have to accept the bitter fact that the current technology hasn’t reached that level of producing solar-powered motors. The available solar panels cannot be relied on as consistent, effective, and worthwhile for powering trolling motors without batteries.
Can I Buy 36 Volt Panels?
You can buy and use a 36v panel to charge your trolling motor’s batteries. With a charge controller, you don’t have to worry about any excessive voltage; you can connect three 12v panels in series or buy a 36v kit.
However, you’ll still get the same amperage when the 12v kits are connected in series, meaning the charging time will be the same as when using a single 12v panel.
5 of the Best Boat Solar Panel Kits
By now, I guess you’ve decided to buy some high-grade panels for your trolling motor – after all, who wouldn’t want to enjoy the benefits that come with using a free, limitless energy supply?
If so, here are five panels worth buying:
This standard 58.7 x 26.8 x 1.4 in (149.1 x 68.07 x 3.56 cm) monocrystalline panel comes with three cables with connectors and can generate up to 5.32 Amp. It’s made to charge both 12v and 24v batteries.
It’s designed for excellent performance even during low-light, cloudy days. The anodized aluminum frame extends its lifecycle. This panel has 14 pre-drilled holes that are compatible with tilt, side poles, and ground mounts. You could also use Z brackets. Its warranty covers two aspects: limited power output (25 years) and material and workmanship (5 years).
This 64.96 x 39.25 x 1.57 in (164.1 x 99.7 x 3.99 cm) panel comes with bypass diodes for excellent low light performance. It can withstand heavy snow loads and high winds. Its aluminum construction is corrosion-resistant, extending its durability. The pre-drilled holes make installation a breeze.
The warranty covers power output (25 years), efficiency rate (5, 10, and 25 years for 95%, 90%, and 80%, respectively), and material and workmanship (10 years).
This 64.57 x 26.57 x 1.38 in (164.01 x 67.49 x 3.51 cm) solar charger’s rugged design and aluminum construction make it durable since it can withstand harsh elements. It comes with multilayered sheet laminations for better performance and longer service life, making it one of the high-grade panels on the market.
This flexible panel comes with Maxeon high-efficiency solar cells for enhanced performance. It’s robust and can withstand elements, making it durable. It’s also earned a spot in the best panels since it’s lightweight, easy to install, and easy to clean.
If you’re looking for a 36v panel that gets the job done, you’ll never go wrong with this product. Although it was initially designed for golf carts, it can be used in various applications. It comes with mounting brackets for quick, easy installation. The charge controller and cables are also high-quality.
Having a solar charger for your trolling motor is a sure-fire way to enjoy the benefit of a natural, unlimited, and safe energy supply. Carrying fuel or plugging your battery pack into local utilities is sometimes inconvenient.
However, with a high-end solar panel, you don’t have to do more work after having a busy day at sea. By the end of the day, the sun has already done its magic, and you can relax as you plan the next day’s adventures. Just ensure your panel has a charge controller and a blocking diode to protect your battery.
Frequently Asked Questions
Can you run a trolling motor from a solar panel?
No, you cannot run a trolling motor from a solar panel. Trolling motors require a minimum amount of power, otherwise, they will not have enough energy to run and do their job properly. Unfortunately, solar panels simply cannot provide enough energy to do the job.
The most powerful solar panels that you can get will provide up to 8 amps of energy. While this is a decent amount of power, it is nowhere near enough for a trolling motor. The majority of trolling motors will require a minimum of 40 amps to run, so it simply isn’t enough.
However, you can use a solar panel to set up a trolling motor, and you can even use a solar panel to provide some of the energy required for the trolling motor. But, a solar panel alone will not be enough to run your trolling motor.
Can you connect a solar panel directly to a motor?
Yes, you can connect a solar panel directly to a trolling motor. However, there are lots of things that will impact whether this is a good decision, or not. For example, the current and power of both the trolling motor and the solar panel will have a huge impact on whether you should connect the solar panel to the motor.
If the current and power of both the solar panel and the trolling motor match, then you absolutely can connect them directly to one another. Ideally, you want the current rating of the motor to be slightly more than the current rating of the solar panel.
However, as long as they match or are at a very similar level to one another, it will work perfectly fine. So, yes, you can connect a solar panel to the motor as long as their ratings match.
Will a solar panel charge a marine battery?
Yes, a solar panel will charge a marine battery. However, it is worth noting that you will need a very powerful solar panel to do the job, and even then it will take considerably longer to charge your marine battery with a solar panel than with a regular charger.
This is because solar panels are much weaker in terms of power than other forms of energy. The supply of energy for a solar panel is often very limited, and this will cause charging to take longer. But, solar panels come with different energy levels, so let’s take a look at how you work out the one that you need.
To figure out the size of solar panel you will need, you need to multiply the volts and amps that you will be charging the battery at together. This will give you a calculation of the watts that the battery needs to charge, and you can buy a solar panel accordingly.
Can I use a solar panel directly without battery?
The majority of devices will need a battery to connect them to a solar panel. Especially devices on a boat. However, there are a few appliances that will not need a battery to act as a middle man.
The majority of devices that need a battery between them and the solar panel are things that are classed as ‘sensitive electronics’. These devices are very sensitive to changes in amperage and voltage, which can result in damage. Solar isn’t a solid source of energy (without a battery in the middle), so sensitive electronics could become damaged by this.
But electronics that are not considered sensitive are perfectly okay to connect directly to your solar panel. These include the trolling motor, as long as the current and power match.
Can a solar panel overcharge a battery?
Theoretically, yes, a solar panel can overcharge a battery. This is because of the charge rate of the battery and the voltage of the solar panel. It is rare for this to happen, but it is something that does occur.
The charge rate of a battery depends on the output current and voltage of the solar panel, along with the battery voltage. If these do not match, or the battery exceeds a full charge, it is possible for the solar panel to overcharge it.
If you want to avoid your solar panel overcharging your battery, it is best to invest in a solar charge controller. This controller will limit the output power of the solar panel, ensuring that there is absolutely no risk of your battery overcharging. No matter how much time it spends connected to your solar panel.