If you are planning to install batteries on your boat, you may be wondering if you need to secure them inside protective boxes. But before investing in battery boxes, you may have a few questions about their purpose.
What is a marine battery box, and what is it used for?
Where do you mount a battery box in your boat? Do you even need one in the first place?
How do you install a battery box?
In this article, we’ll answer all of these questions and more!
Table of Contents
What is a Marine Battery Box?
If you’re new to the world of marine batteries, you may be wondering: what is a marine battery box in the first place?
A marine battery box is a specialized type of protective box used for housing a marine battery on a boat. Most often, these battery boxes are made of durable, heavy-duty plastic, though sometimes they are made of aluminum or stainless steel instead.
Usually, battery boxes are only large enough to house one battery of a specific size and shape. Sometimes they are large enough to house multiple batteries.
Other battery boxes are universal, able to hold only one battery at a time, but support batteries of various group sizes and dimensions. Other battery boxes have specific dimensions for specifically-sized batteries.
Before choosing your battery box, it is important to know your battery’s group size and dimensions to choose a box that will fit the battery well. This is true even if you choose a universal battery box.
Most marine battery boxes have holes for battery cables; others have external terminals and plugs built into the box. They also have ventilation holes to prevent a buildup of toxic fumes from battery acid.
Battery boxes are generally resistant to corrosion, chemical damage, UV radiation, and other types of damage they may be exposed to. Their job is to protect the battery inside, so they must be tough and durable.
Some battery boxes have built-in circuit breakers and power centers, while others have a simpler, basic design.
As you might imagine, the boxes with more features will cost more than the simpler ones, and depending on your setup, you may not need all the bells and whistles. But more on that in a moment.
What is a Marine Battery Box Used For?
The basic function of a battery box is to protect your battery from damage caused by many different kinds of exposure.
Marine batteries are tough to begin with; they are made to withstand water, temperature variations, and other such exposures. But they are not invulnerable. It is best to keep your boat batteries inside a protective box, in many cases.
This is especially true if you have flooded lead-acid batteries, which must be secured in an upright position. These batteries will leak battery acid if they are tipped over or shaken up too much.
A battery box will keep your battery secure, limiting the number of shocks and vibrations it has to withstand and nearly eliminating exposures such as moisture and UV radiation.
Using a battery box can extend your battery’s lifespan by protecting from these everyday marine exposures and keeping it in top shape year after year.
Do Marine Batteries Need to Be in a Box?
Of course, all this talk of battery boxes raises an obvious question: do you need one on your boat? Afterall, marine batteries are designed to handle a lot of abuse; do you really need to spend extra money to protect them?
In most cases, investing in a battery box is a good idea, but it isn’t always necessary. Whether or not you need a battery box can depend on the type of boat you have and its overall design and setup.
If your boat has a battery compartment, you do not need a battery box. The battery compartment will provide all the protection the battery needs.
If you need to secure your battery inside its compartment, you can use a battery tray and straps. A battery box is an overkill if you have a battery compartment, and the box may not even fit in the compartment in the first place.
If your boat doesn’t have a battery compartment, then it’s best to use a battery box. In this case, the box will likely be the only thing protecting your battery from unwanted exposures and potential damage.
You will especially want to use a battery box if you have a small boat, such as a kayak or canoe, as these smaller boats are closer to the water and often subjected to extra levels of spray, UV radiation, and other exposures.
Where Do You Mount a Battery Box?
You can mount your battery box just about anywhere there is space on your boat. You’ll want to keep in mind what you plan to use the battery for and where these devices are located relative to the battery.
For example, you wouldn’t want to mount your battery box on the boat’s bow if the battery inside was operating a transom-mount trolling motor.
Secure the battery box to your boat’s deck in a convenient spot. It doesn’t have to be in any specific spot, but you should keep it close enough to your devices and accessories to easily connect the battery to devices.
Keep in mind that, with smaller boats, you may not have enough space to be picky; you will have to mount the box wherever you may have space.
The good news is that, with smaller boats, everything is close together. Depending on how small your boat is, it may not matter if you have to mount your battery box on the bow for a transom-mount trolling motor–it will still be close enough for the cables to reach easily.
How Do You Secure a Battery Box?
When using a battery box, the box must be securely mounted to the boat; otherwise, it may slide or roll around on the deck, causing damage to the battery and possibly to the box and any cables hooked up to it.
There are different methods of securing battery boxes. Some of the most common ways include:
- Tie down straps: Most battery box tie down straps are made of durable nylon or similar materials, with clamps to tighten the straps against the box. There are many different options available, some more well-made than others.
- Stainless steel screws: Some battery boxes are simply mounted to the deck using screws. These will most likely come with the screws included, but if they don’t, or if you need to replace them, be sure and select high-quality stainless steel screws.
- Foot clamps: Some battery boxes come with foot clamps to secure them to the deck. The clamps are mounted and snap onto the box, holding it secure against the deck.
How to Install a Marine Battery Box?
Check out this video for an example of a battery box and how to install it:
Follow the steps below:
- Choose where to mount it: As noted above, you will want to mount the box in a convenient location close to the devices your battery will be powering. There is no wrong or right spot for mounting–just make sure it’s out of the way while still being accessible.
- Decide how to secure it: Depending on the battery box you choose, mounting straps or hardware may be included. If they are not included, check the user’s manual to see how it is recommended to secure this particular battery box.
- If you use straps, follow the instructions included with the straps. In most cases, the straps will wrap over the middle part of the box, tightening by way of a clamp or buckle at the top.
- If you use screws, thread the screws through the appropriate holes in the battery box. You may want to use a power drill to drive the screws into the deck. Be careful to choose a spot that will support the screws and not cause significant damage to the boat.
- If you use foot clamps, follow the instructions to screw the clamps into the deck. Snap the battery box into place, rocking it back and forth to make sure it is secure.
- Place the battery inside and wire as necessary: Again, some battery boxes will have holes for the cables; if so, thread them through these holes, then connect them to the battery inside.
- Connect your devices, chargers, etc.: Hook up any device or accessory you plan to run off your battery, as well as any onboard chargers.
You may need to connect these to terminals on the outside of the battery box, or you may need to thread them through to the battery inside. Either way, once everything is hooked up, test each device to make sure you have a good connection.
Marine battery boxes are used to protect marine batteries from the sea spray, vibrations, UV radiation, and other such conditions experienced on a boat.
Battery boxes are unnecessary if your boat has a battery compartment; the compartment will offer all the protection your battery needs.
On the other hand, a quality battery box may prove to be a good investment if your boat has no compartment, as the box will be the only means of keeping the battery out of the weather and may even extend its overall lifespan.
Sarah Hood has been writing for Anchor Travel since 2021. When she’s not writing, she enjoys cooking, singing, and spending time in the great outdoors.