If you’re reading this article, then chances are, a regular deep cycle battery isn’t going to cut it for you. Either you’re looking for something smaller and more lightweight, or you’re looking for something cheaper . . . or maybe both.
Lawn mower batteries would certainly fit the bill. But would they work for powering trolling motors?
What are the pros and cons of using a lawn mower battery over a marine or deep cycle battery?
And what are some other lightweight, inexpensive alternatives that might work better than a lawn mower battery?
In this article, we’ll answer all of these questions so you can make an informed decision about what you use to power your trolling motor.
Ready to get started?
Table of Contents
Will a Lawn Mower Battery Power a Trolling Motor?
The short answer is yes, in many cases, a lawn mower battery will power a trolling motor. But when it comes to actually using a lawn mower battery in this way, the answer isn’t quite so simple.
In terms of battery power, trolling motors generally aren’t too picky as long as the battery has the proper voltage for the motor.
That said, just because a battery will power your trolling motor doesn’t mean you should use it in real world scenarios out on the water.
Lawn mower batteries aren’t rated for marine use, though they are used for various outdoor purposes so they can usually handle a decent amount of heat, cold, and moisture. The bigger issue is the amount of power they have to give.
If you were to compare lawn mower batteries to deep cycle batteries, you could say the lawn mower battery is like a drinking glass and the deep cycle battery is like a 5-gallon bucket. Fill them up with water, then slowly pour them out.
It’s easy to imagine which one will take longer to drain and will produce the higher output.
What’s more, deep cycle batteries are specifically made for frequent and deep discharges. In many cases, you can discharge to 80 or 90 percent without harming the battery.
If you were to run a lawn mower battery down to 10- or 20-percent capacity on a regular basis, you would probably kill the battery within a year, and perhaps even within a few months depending on how often the battery was charged and discharged.
None of this is to say you can’t use a lawn mower battery for your trolling motor; but if you do, you need to understand the limitations of the battery and not expect it to perform as well or as long as a deep cycle battery.
With that in mind, let’s take a closer look at some of the specific pros and cons of using a lawn mower battery for your trolling motor.
Lawn Mower Battery for Trolling Motor: Pros and Cons
- Lawn mower batteries don’t take up much space. Most lawn mower batteries are relatively compact since they’re designed to fit in a small space under the lawn mower hood.
Their small size makes them a good fit for kayaks, small inflatables, and other small boats that may not have a lot of extra space after you’ve loaded in your gear and passengers.
On that note:
- Lawn mower batteries are lightweight. If you’re concerned about space in your boat, then you’re probably worried about weight as well. Lawn mower batteries weigh a fraction of what most deep cycle batteries weigh.
Not only does this keep you from having to worry about your boat’s weight capacity and making sure the weight is evenly distributed, but it also makes the batteries easier to move around. And who wouldn’t love a more portable battery?
- Lawn mower batteries are inexpensive. In general, lawn mower batteries are going to be cheaper than marine or deep cycle batteries. This is mainly because of differences in design--deep cycle batteries are made to withstand much deeper discharges.
- Lawn mower batteries need frequent recharging. When these batteries are used in lawn mowers, they primarily provide the starting power and are continually recharged by the running of the motor--much like a car battery.
When used with a trolling motor, they are the sole source of power and aren’t recharged while the motor’s running. For this reason, lawn mower batteries run out of power really quickly--sometimes in as little as 10 minutes.
- Lawn mower batteries are not rated for marine use. As noted above, lawn mower batteries are made for use outdoors, so they are somewhat waterproof and can handle a variety of temperatures.
But when you’re out on the water, the battery will likely be subjected to splashing, direct sunlight, and frequent jarring. Marine batteries, and many deep cycle batteries, are made specifically with this added abuse in mind. Lawn mower batteries are not.
As a result, lawn mower batteries may become easily damaged or corroded and may not last an entire season, whereas marine and deep cycle batteries can be expected to last at least two or three seasons.
- Lawn mower batteries are not designed for frequent deep discharges. Discharging the battery too much, too often will cause the battery to wear out more quickly. You’ll find that over time, it doesn’t charge completely or last as long between charges.
It won’t take long for the battery to stop holding a charge completely, and at that point there’s nothing you can do but buy a new battery.
How to Connect a Lawn Mower Battery with a Trolling Motor
If you do decide to go ahead and use a lawn mower battery with your trolling motor, you will need to connect the cables to the battery terminals as you would when using any other type of battery.
- First, mount your trolling motor and the battery wherever you want them to go in the boat.
- Next, locate the battery cables running from the trolling motor. There should be one red cable and one black cable.
- Determine which battery terminal is positive (+) and which one is negative (-). Connect the red cable to the positive terminal and the black cable to the negative terminal.
That’s all there is to it. As noted above, this process remains basically the same no matter what type of battery you’re using. For a visual on the process, check out this video.
Lawn Mower Battery Alternatives for your Trolling Motor
So, lawn mower batteries may not be the answer if you’re looking for a cheap, lightweight way to power your trolling motor. Are there any other options?
Actually, there are several alternative batteries and power sources you could explore, depending on the exact features you’re looking for.
Wheelchair/ Scooter Battery
Batteries designed for wheelchairs and scooters are usually deep cycle AGM batteries, meaning they will give you the power you need for hours at a time and the ability to discharge deeply without hurting the battery.
These batteries are generally smaller and more compact than most deep cycle batteries, and they are also relatively lightweight. They’re probably going to cost you a bit more than lawn mower batteries, but they last longer and get the job done much more efficiently.
If you’re willing to pay some money, investing in a lithium battery can be a great decision, especially if you’re out on the water all the time and for long periods of time. Lithium batteries are extremely lightweight and usually more compact than other types of batteries.
Many lithium batteries will last ten times as long as flooded or sealed lead acid batteries, and they can also last significantly longer between charges. Their major drawback in the associated price tag, so if you’re looking for something inexpensive, you probably won’t want lithium.
Though it’s not ideal in all circumstances, you can sometimes use a jump starter in place of a battery to power your trolling motor. Jump starters are even smaller, lighter, and easier to use than lawn mower batteries.
Of course, like lawn mower batteries, jump starters are used for starting engines and don’t provide a ton of power themselves. That said, they usually last a bit longer than lawn mower batteries, sometimes up to an hour or two.
Lawn mower batteries may work to power trolling motors, but in most cases they won’t give you more than a few minutes on the water. They aren’t designed to charge and discharge frequently, so using them with your trolling motor may damage them and shorten their lifespan.
If you were thinking of using a lawn mower battery with your trolling motor, why not check out one of the alternatives listed above? Scooter batteries, lithium batteries, and jump starters will all provide the compact, lightweight power source your small boat may need.