What Is a Deep Cycle Battery?

What Is a Deep Cycle Battery?

Ask a boat owner how easy it is to own a boat, and they’ll laugh at you. Boats take a lot of work. Even small fishing boats require constant maintenance and cleaning to keep the boat up and running.

Obviously, owning a boat is worth all of the effort. Freedom on the water is something that can’t be matched on land.

If you’re an aspiring boat owner or have recently purchased your first boat, it’s time to start learning about all of its components, start with your marine battery system. 

What is a deep cycle battery, and how does it differ from the other battery on board (yes, you have two)? Keep reading to learn about this crucial piece of gear that you cannot power your boat without. 


How Boats Receive Power

Your boat is powered in a number of ways, though the motor gets all the credit. 

Yes, you have a motor, and it’s the motor that propels your boat forward. The motor enables you to reach insane speeds and gets you where you need to go. 

Most boats use an outboard motor. These are the motors that sit on the rear of the boat, easily seen by passengers on the boat. They are not built into the hull of the boat like inboard motors are. Outboard motors are easy to clean and maintain since they are always accessible.

But in order to start your boat, you need a battery. You have two on your boat, and each does something different; the starting battery and deep cycle batteries.

Your starting battery (cranking battery) provides a large amount of power in a short amount of time. This burst of power is what kicks the motor on. Once the motor is on, it sustains those batteries.

So what type of battery is a deep cycle? These are responsible for everything else on your boat.

What Is a Deep Cycle Battery?

So what is a deep cycle marine battery? And what is a deep cycle battery used for? It’s used for many things.

Deep cycle batteries are those that release power slowly over time. They are intended to last a long time, unlike starting batteries, which release most of their power all at once.

Deep cycle batteries, like the Enduro battery, can power smaller trolling motors. Trolling motors are much smaller and quieter than outboard engines. Sometimes, when fishing in shallow water, it’s more effective to use the smooth trolling motor, rather than scaring the fish away with an outboard.

Along with these small motors, your deep cycle battery also powers your boat’s electronics. Have a sound system? It uses power from the deep cycle battery.

Have any lights on your boat? Yup, that comes from the deep cycle battery, too. You get the point.

Deep cycle batteries are designed to be charged and discharged hundreds of times. They can last a long time if properly cared for. 

If you have a tiny little Jon boat that doesn’t have any electronics on board, you might not have any need for a deep cycle battery. But all other consumer boats will have them.

Why Do You Need Two Different Marine Batteries?

Why can’t you use one battery for both functions on a boat? Having just one battery saves space and weight on the boat.

Good question. Using just one battery could get you into trouble out on the water, which is the last place you want to run into trouble.

If you just had a cranking battery onboard, then it would be used continuously, to power things like your sound system, fish finder, or trolling motor. But these batteries are intended to run continuously. Doing so could drain the battery very quickly, causing it to overheat. 

Put another way, the battery could die very quickly, and you could be left without a battery to start your motor.

On the flip side, using only a deep cycle battery, you might not be able to start the motor at all, since these batteries can’t provide as much power in a short period of time to get the motor running. 

In either situation, you run the risk of getting stranded and having to call for help. A situation that no boat captain ever wants to be in. 

Alternatives to Having 2 Batteries 

Your boat is going to run best with the two different batteries on board. However, in some instances, boats can run with a streamlined solution; the dual-purpose marine battery.

This type of marine battery combines the function of the cranking battery, with the long-lasting nature of a deep cycle battery. But while this option might work for some smaller boats, it’s not right for most people with normal-sized, or large boats.

By combining two batteries into one, you are basically reducing the power of each battery. You have to make sacrifices if you want to save weight, space, and money. 

So if you have a large boat, with a large outboard motor, a dual-purpose battery might not be able to generate enough power to get it started. Or, it might get it started the first time, but when you’re ready to come home after a day of fishing, it might not be able to start the motor a second time.

So before buying a dual-purpose battery, ensure it’s going to work well with the size of your boat and motor. 

While it can save you money, since you only need to buy one battery instead of two, it requires you to be very diligent about maintaining battery levels while out on the water. These batteries might also be more sensitive to heat and harsh conditions. If the battery dies or fails you in some way, was the money saved actually worth it?

Know Your Boat

So what is a deep cycle battery when it comes to operating a boat? It’s the long-lasting battery that provides continuous power to electrical devices on a boat, such as smaller trolling motors, fish finders, or speaker systems.

Without one, your boat ride might be a little boring, and you may end up getting lost if you can’t power your GPS unit.

Looking for more boat tips like this? Head over to our blog now to keep reading. 

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