What Are The Main Types Of Boat Batteries?

There are several different types of batteries used to start and power marine vessels. Replacing a worn-out battery with a new one designed for a different application can leave you stranded in the water. Most boats will need a battery bank, not just a single boat battery. Here is a helpful list of the primary boat battery types and their uses to help you correctly replace your old marine batteries.

Starting Power

Batteries used for starting a marine engine are built specifically for that purpose. If you try to power a device like a trolling motor, appliance, or large-scale electric equipment with them, this misuse will burn out the battery. Marine starting batteries are made to give out a short burst of intense current over a small period of time and then receive rapid recharging from the running boat engine. A marine starter battery should never be discharged very deeply because this will damage the battery's ability to hold a charge.

Deep Cycle

Deep cycle batteries are designed to give a steady current over a long period of time. This makes it perfect for powering house systems like appliances and heating/cooling equipment for live-in boats and fishing boats that take multiple-day excursions. Deep cycle batteries can handle dropping to around 80% discharge without damaging the battery. They do not have enough amperage to start large boat engines but are ideal for running an electric trolling motor that requires a high constant draw of electrical current.

Dual Purpose

Some marine batteries are designed for a dual-purpose application with both starting and deep cycle power in mind. They're primarily used for sailboats and other boats that have lower engine demands. Dual-purpose marine batteries can provide long-term power for equipment and have enough cranking power to start an engine. Some are designed to run trolling motors or electrical sailing equipment, but most are better used only for limited power applications.

Arrangements for Batteries

If you have a larger boat, it's almost inevitable you'll need more than one type of battery. It's a question of how to arrange and store them once you've determined how many deep cycle and starting batteries you need. Single multi-purpose battery banks can be used to start and power a smaller vessel from one convenient spot. Larger fishing boats may require separate battery banks to power the trolling motors and for starting batteries. Deep cycle batteries for running house systems can also be located away from starting and trolling batteries.

Knowing the right marine battery type to use makes all the difference in the performance of your boat. Check the manufacturer's recommendations for powering the boat to ensure you're meeting the cold cranking amperage and other requirements.