By Frank Sargeant, Boating Editor

Anglers today are using electrical current at rates never imagined a few decades ago. With everything from 24- or 36-volt trolling motors to power anchors such as the Power Pole, to several big livewell pumps, to an array of electronics on board, to say nothing of starting the outboard, it takes a lot of juice to keep your boat going all day long—or particularly on those multi-day trips to the outback where you won’t have the chance to plug into a charger.

Your outboard charging system will likely keep your starting battery at full power if you have a dedicated battery for the engine only. But in an effort to cut weight, many who fish in shallow water go with a single battery to handle everything—including power for a 12-volt troller. Alternatively, for those who carry three or four batteries, typically only the starting batteries get the charge. Clearly, you need high-quality marine batteries to do the job—and you also need to keep the batteries well-maintained.

Fortunately, there are numerous new battery designs that provide more current for more hours than ever before. They don’t leak and they never need water. They’re also tougher and longer-lasting than their predecessors. The only thing they’re not is cheaper: Some of the new technology costs two to three times as much as the traditional lead/acid battery.

Most of us run our batteries until they die, then wind up going to the nearest super store and buying whatever marine battery is on sale. It’s better to plan replacement, do a little research, and buy the right battery for the job—one that will last a long time, because a bigger part of the pain than paying for a new battery is the knuckle-busting work of pulling the old one out and installing the new one. You want to do this chore as infrequently as possible, because they are usually in tight spots where getting them out requires blood loss and possibly a hernia.

For deep-cycles, the ones you use for your troller and everything else except starting the outboard, the biggy is the number of cycles a battery’s designed to deliver. A cycle is a discharge and recharge, the job for which deep-cycles are intended. A good-quality lead/acid battery is likely to deliver 350 cycles. Compare that to a gel-cell battery, which can pump out up to 500 cycles. So you can see the gel cel is worth at least 42 percent more, right out of the box, based on its design life. Plus, you don’t ever have to add water, and they don’t release corrosive gas into your bilge. On the other hand, they cost more—a lot more. A single Group 31 size gel-cel is around $250, or around 80 percent more than what a lead/acid Group 31 battery costs, at around $140. It’s not far from being a toss-up, if both batteries come up to their design life in number of cycles. What it’s worth to not have to replace the battery for an extra year or so, of course, is up to you.

Absorbed Glass Mat (AGM) batteries, with the electrolyte wetting microfiber glass mats between the positive and negative plates, offer varying life spans from 300 cycles upward. AGM makers say the batteries offer many advantages: They require no maintenance, they don’t leak, they discharge as little as one percent per month while not in use and they recharge much faster than flooded-cell batteries. They are warranteed for 18 to 60 months, compared to 12 to 36 months for most lead/acid batteries. However, again, they cost twice as much. Bottom line is if you can afford to pop for the gel or glass mat batteries, they will be worth it in the long run. If you need to save a few bucks now, you can do well with a quality lead/acid, but check it regularly and be aware that you will have to replace it more frequently.

Match the Battery to the Purpose

Most trolling motor manufacturers suggest 105 amp hour batteries for everything from 12- to 36-volt systems, and these are the Group 31’s, typically about 13 inches long with weights of 65 to 70 pounds, compared to Group 27’s, the next size down, which put out around 90 amp hours. They measure about 12.5 inches long and weigh around 55 to 60 pounds. Cost is typically $30 to $50 less than Group 31’s of similar quality.

Starting batteries, on the other hand, are typically Group 27 or Group 24. The cold-cranking amperage is the figure most used to compare these batteries; it’s the amount of current the battery will deliver for 30 seconds at 0 degrees F while still maintaining at least 7.2 volts. (Of course, in Florida, there are not a lot of zero-degree mornings, so you can expect more time at full power.) You want something that will deliver in the neighborhood of 600 CCA’s or more for most 4-cylinder and larger outboards. Merc suggests 775 CCA’s for its larger Verado models. Group 24 batteries come with an assortment of outputs within the same size case, so look carefully at the CCA figure: It’s possible to buy a $60 Group 24 lead/acid that puts out only 440 CCA’s, while a version that puts out 875 CCA’s, in the same case size, goes for about $100.

Exide makes dual-purpose batteries in both their Stowaway and Nautilus lineups; these function both as a deep-cycle for trolling motors and other accessories, and as a powerful source of current for starting V6 outboards. If you can get by with a single battery, something like this can be useful and save money; www.exide.com. West Marine’s SeaVolt Dual Purpose batteries are similar, and the company says they will last over 200 cycles in deep discharge use; www.westmarine.com. Odyssey, manufacturer of a wide array of batteries and chargers, offers a dual-purpose AGM battery, the Trolling Thunder, that features pure lead plates and reportedly has twice the power and three times the life as similar-sized conventional marine batteries due to the use of thin lead plates. Odyssey marine batteries come with 3- or 4-year full replacement warranties; www.odysseyfactory.com. Optima’s AGM blue top series are designated for deep cycle/starter applications; www.optima-batteries.com.

Share the Charge

Aftermarket products like the BassMaxx from Wells Marine or the Battery Link from Blue Sea distribute engine alternator charge to all your batteries, including the trolling motor batteries. You get more juice in the trollers—but less in the starting battery. However, the devices can be set to deliver as much charge as you like to the various batteries, or to stop charging your auxiliary batteries when the starter battery gets low, and divert all charging to it. The BassMaxx can also be switched to use the troller batteries to give your starting batteries a boost—very useful; www.wellsmarinetech.com; www.bluesea.com.

Cranking Confidence

If you want to add a little insurance to make sure you’ve got adequate power to start your outboard, consider one of the portable “jumpstart” systems, which are basically mini-batteries with a charger attached. If your starting battery gets too low to crank the outboard, you clip the jumpstart to the terminals and get a surge of power that does the job. They’re about $80 for a 450-amp model that also functions as a 12-volt light; www.vectormfg.com.

Keep Your Charge

To maintain your batteries, why not go with a trouble-free, fully automatic charger?

Xtreme Charge battery charger includes a battery test circuit to make sure your battery is still capable of taking a charge, plus a pulse-charging system which the company says often revives “dead” batteries and extends their useful life for months. The pulse system plus the controlled charge is said to extend the life of new lead-acid deep-cycle batteries far beyond their normal span, as well, by preventing overcharging. The system monitors the battery’s charge level and cuts input as it approaches full charge, thus preventing overcharging, heat build-up and gassing off the electrolyte; www.xtremecharge.com.

On-board chargers are increasingly popular for anglers who want to keep batteries fully topped off, at home or on the road. Simply bring along an extension cord, and plug the unit in at the dock. Minn Kota manufactures an extensive line of on-board chargers to handle from one to four batteries simultaneously. Recovery times depend on the model chosen. For example the MK 210 charges two deep-cycle batteries automatically in 10 to 12 hours with 10 amps total output. Or, go with the MK 230, with increased output, for the same job in only 3 to 5 hours. Minn Kota also offers on-board battery maintainers, which provide 6 amps total output, designed for keeping batteries charged during prolonged periods of inactivity. Visit www.minnkotamotors.com.

SWA