Inside Edge

Selecting A Marine Battery

Which Battery is Right for You?

Never before has the marine industry seen such a vast array of boats and watercraft equipment being used for numerous types of recreation and commercial use. Even within just a single market like bass fishing, there are many different power needs for batteries to deliver. These needs can vary from infrequent to frequent use or to powering multiple electronic accessories to just a few. Varying needs directly affects the type of service required by a marine battery. It would be impossible to make one battery that would perfectly match each and every consumer’s need. That’s why different types of batteries such as Gel, AGM, and flooded designs are made to meet the multiple demands of the fisherman as well as the entire marine market.

Marine Battery Types

Flooded Batteries

Flooded lead-acid batteries are the most widely used batteries both in automotive and marine applications. Lead-acid batteries are usually less expensive than either the Gel or AGM batteries, but do not provide the same cycle life and convenience. Most flooded batteries require maintenance. Electrolyte levels must be maintained above the cell’s plates.

SVR Gel Batteries

Sealed, Valve-Regulated (SVR) Gelled-electrolyte batteries offer many significant advantages over conventional “flooded” batteries. Gel batteries are spillproof* and leakproof, and resist over-discharges that can shorten the life of the battery. Gel batteries have a self-discharge rate of less than 1% per month (at 68°F). They provide ample cranking amperage for quick, sure starts, and deliver longer trolling time than comparable flooded models. Their SVR design minimizes gassing, making them safe to install around people and sensitive electronic equipment. Gel batteries offer a viable alternative when you can only choose one battery. Gel batteries are maintenance-free.

Charging: For longest life, always use a good, constant potential, voltage-regulated charger. For 12-volt Gel batteries, charge to at least 13.8 volts, but no more than 14.1 volts at 68°F (20°C). Do not charge in a sealed container.

SVR AGM Batteries

Sealed, Valve-Regulated (SVR) Absorbed Glass Mat (AGM) batteries use special absorbed electrolyte technology that is superior to flooded lead-acid batteries. Fine, highly porous microfiber glass separators absorb the electrolyte*, increasing efficiency by lowering internal resistance and boosting capacity.Lower internal resistance also means that the batteries can be recharged faster than conventional batteries,† allowing the user to put them back into operation sooner. The completely sealed, valve-regulated AGM battery eliminates gas emissions and acid leakage for longer and safer battery operation. AGM batteries are also completely maintenance-free.

Charging: Use a good, constant potential, voltage-regulated charger. For 12-volt AGM batteries, charge to at least 14.4 volts, but no more than 14.6 volts at 68°F (20°C). Do not charge in a sealed container.

* Rated non-spillable by International Commercial Airline Association (ICAO), International Airline Transport Association (IATA) and DOT definitions.

Marine Battery Service

One of the best ways to choose the right type of battery is to determine the type of power service your battery needs to provide. Marine batteries can be designed to focus on one of the below power needs or a combination of them for a multi-purpose use.

Marine Starting Service

When a battery is called upon to deliver several hundred amps of power to the starting motor, the battery must be able to deliver this power quickly...within a few seconds. This power comes off of the surface of the plates inside the battery. Therefore, a battery with more plate surface area and less resistance will deliver power quicker than one with less plate surface and high resistance. That’s why starting batteries are made with thinner plates...because you only use the power off the surface of the plates for starting the engine.

Deep Cycle Service

A deep cycle battery is called upon to deliver a long, slow discharge of fewer amps...for several minutes or hours...in a deep cycle application, such as running a trolling motor or heavy marine accessory load (e.g. depth finders, fish finders, radios, radar, lights, coolers, house power, etc.). In this case, the power comes from deep within the plates, not merely off the surface as in starting. Therefore, deep cycle batteries are specially engineered with heavier, thicker plates with fiberglass reinforcement, special power-producing active material and special heavy-duty separators.

With these features, the battery can withstand the potentially damaging effects of continual deep discharge and recharge. The thinner plates of a starting battery cannot handle this constant deep cycling, and will fail in short order.

Dual Purpose Deep Cycle/Starting Service

Dual purpose batteries are ideal for applications that require starting and deep cycle service. They deliver powerful cranking amperage for easy starting, and low amp draw service for reliable auxiliary power. Dual purpose batteries are a perfect compromise between the unique demands of starting service and deep cycling, low amp draw service.

Deep Cycle, Starting, Dual Purpose...How Should I Choose?

Ideally, you could have one battery for starting and an auxiliary deep cycle battery for the trolling motor and accessories. If however, you can only have one battery on board, the one you choose depends on the power draw required. For light to moderate-duty low amp draw service, choose the dual purpose battery, specially designed to handle both starting and cycling. For heavy-duty cycling, choose the deep cycle battery. This will give you enough cranking amperage to start your engine, and the most reserve power to keep your trolling motor and accessories running longer.

Use the above convenient chart to help you select a battery type appropriate for your specific situation.

BATTERY SAFETY

Remember, even more important than choosing the right battery is adhering to proper safety warnings and instructions before handling or installation.

• Always wear safety glasses when working on or near batteries.

• BE CAREFUL! Batteries produce explosive gases.

• Keep sparks, flames and cigarettes away from batteries at all times.

• Lead-acid batteries are virtually 100% recyclable so be sure to return your used lead-acid battery to a retailer. In most states it is illegal to discard a battery in the trash.

Proposition 65 Warning: Batteries, battery posts, terminals, and related accessories contain lead and lead compounds, and other chemicals known to the state of California to cause cancer and birth defects or other reproductive harm. Wash hands after handling!