EnerSys® Experts Share Their Top Five Marine Battery Maintenance Tips

The battery in your motor vehicle is probably used and recharged by the alternator daily. However, marine batteries may sit dormant for days, weeks or even longer. Practicing basic maintenance can help preserve battery life and enable premium power performance when you need it.

There are three basic types of marine batteries: Absorbed Glass Mat (AGM), gel and traditional flooded lead acid. The latter requires more maintenance.

Helpful maintenance tips from the battery pros at EnerSys®

EnerSys® ODYSSEY® battery experts have compiled a list of their top five tips to help you get the most from your marine battery this season. As always, be sure to follow the manufacturer’s guidelines for battery care and handling and direct any questions to your battery professional.

Tip One: Top Up Flooded Lead Acid Batteries

If you own a flooded lead acid battery, check the electrolyte level periodically. Remove the caps and use a flashlight (if necessary) to see inside the battery. If needed, add water until the electrolyte level just covers the top of the plates, or per the manufacturer’s instructions.

Tip Two: Perform a Regular Inspection

Inspect and ensure that battery connections and cables are clean and undamaged. Tighten any loose connections. Check the battery case for cracks, and flooded lead acid batteries for leaks. Check all battery connections for corrosion. There should always be a protective boot over the positive battery terminal to greatly reduce the risk of sparks from arcing.

Tip Three: Keep the Battery Clean
Remove any corrosion from battery terminals and cable connectors. Periodically clean dirt and grime off the top of your battery. Excessive build up can cause a battery to self-discharge.

Tip Four: Keep the Battery Properly Charged
Keeping your battery properly charged is essential to help maximize battery life and performance. Flooded lead acid batteries may lose up to 5% of their charge per month if left idle. However, overcharging or undercharging a marine battery could reduce battery lifespan. A “smart” marine battery charger designed for permanent installation can be connected to batteries and has the capability to automatically reduce the charge to avoid overcharging.  

Tip Five: Check the State of Charge Periodically

If you do not already own one, consider purchasing a digital multi-meter. Generally, one with a 20-volt scale is appropriate for marine batteries. Ideally allow the battery to rest, unloaded or after charging, at least 12 hours to obtain a more accurate reading. Place the probes on the terminals to obtain a reading.

Since the 100% State of Charge (SOC) requirement depends on the battery technology being tested, consult the battery manufacturer to determine what voltage corresponds to 100% SOC.

Your best bet when selecting a marine battery is a high-quality, sealed AGM battery, such as the ODYSSEY® Marine Dual Purpose battery. You’ll get the combined advantages of high cranking power, deep cycling capability (up to 70% longer than conventional deep cycle batteries) and rugged resistance to impact, vibration and extreme temperature. This virtually maintenance-free battery also features the highest recharge efficiency of any sealed lead battery on the market, with up to three times the life of conventional flooded lead acid batteries.

A rugged, dependable and long-lasting battery that requires less maintenance means that you can spend more time on the water.

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EnerSys, the global leader in stored energy solutions for industrial applications, manufactures and distributes energy systems solutions and motive power batteries, specialty batteries, battery chargers, power equipment, battery accessories and outdoor equipment enclosure solutions to customers worldwide. Energy Systems, which combine enclosures, power conversion, power distribution and energy storage, are used in the telecommunication, broadband and utility industries, uninterruptible power supplies and numerous applications. Motive power batteries and chargers are utilized in electric forklift trucks and other industrial electric powered vehicles requiring stored energy solutions. Specialty batteries are used in aerospace and defense applications, large over-the-road trucks, premium automotive, medical and security systems applications. EnerSys also provides aftermarket and customer support services to its customers in over 100 countries through its sales and manufacturing locations around the world. With the NorthStar acquisition, EnerSys has solidified its position as the market leader for premium Thin Plate Pure Lead batteries, which are sold across all three lines of business. More information regarding EnerSys can be found at


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