Power hungry: The basics of boat batteries

Tim Horton launched his boat just below the dam on Alabama's Lake Wilson. He had just been crowned the 2000 B.A.S.S. Angler of the Year, and we were headed out on a photo mission to catch a few smallmouth.

Tim Horton launched his boat just below the dam on Alabama’s Lake Wilson. He had just been crowned the 2000 B.A.S.S. Angler of the Year, and we were headed out on a photo mission to catch a few smallmouth.

 We reached the dropoff near a bluff bank, picked up rods, took the obligatory tying-on-a-crankbait pictures, and then Horton dropped the trolling motor into place. When he stepped on the control pedal, there was nothing. No sound, no movement, nothing.”Hmmm,” I said to myself, “batteries.””Batteries,” said Bruce Stanton, Pradco’s public relations director at the time.”I just charged them,” said Horton. “They shouldn’t be down.”

 He was right: The batteries weren’t at fault. Instead, it was a faulty plug, which Horton quickly replaced. So, we did make it in time to take pictures of big smallmouth in the evening light.The fact that all three of us had a knee-jerk reaction that the batteries were the bad guys in this trip is indicative of a weak spot in bass fishing.

 Batteries, whether it’s the cranking battery or the deep cycle source of our positioning power, ruin more trips than any other mechanical cause.Or perhaps it would be more accurate to say that faulty batteries ruin trips, and healthy ones make our fishing much more enjoyable.Why batteries cause so much trouble is a puzzle, as keeping your batteries healthy is easy. Here are some guidelines that will help you maintain good, strong batteries that won’t leave you whimpering in your boat bag at the launch ramp.

 Understanding batteriesThe most important part of battery care is understanding the batteries themselves. Batteries depend upon a chemical reaction of sulfuric acid with lead plates to create direct electric current. As the reaction proceeds, sulfates are deposited on the plates, reducing their ability to produce current.

 Recharging the batteries puts the sulfate back into the solution, which in turn gives the battery the potential to provide electricity once again.Batteries fail for a number of reasons. One is that fishermen choose the wrong one for the application. Marine batteries are more expensive because of their construction, and on occasion, fishermen pick cranking batteries or deep cycle batteries that are intended for use on land because they can be significantly cheaper. That’s foolish economy, because a battery built for use in a car is simply not strong enough to withstand the rigors of a bouncing ride in a bass boat. The battery might be able to handle it for a while, but repeated abuse will loosen plates, crack cases and set the stage for failure. Marine batteries, with their heavier plates and stronger internal construction, are built for rough duty. Picking the right type of marine battery is also of importance to continued health. There are two basic types of batteries: cranking and deep cycle.Cranking batteries are designed to yield a lot of power in short duration. The design provides the electrical push necessary to turn over motors, and that push is usually measured in cranking amps. Cold Cranking Amps is the normal rating for battery capacity. It measures the amount of power available in a quick burst at 0 degrees Fahrenheit.A new measure is coming into play in the marine trade, and that is Marine Cranking Amps, measuring the power available in the same fashion, but at 32 degrees.Deep cycle batteries are built to deliver smaller doses of power over a longer period of time. This power is measured in amp-hours, a figure that will provide you with the ability to judge your battery needs as a fisherman.You only need look at the amp draw of your trolling motor at various speeds (high speed is a good standard) and divide that into the amp-hour rating of your deep cycle to see how long you can fish at that speed.Another reason for battery failure is that fishermen substitute cranking batteries for deep cycle.Cranking batteries won’t work for deep cycle use for very long, because they aren’t designed to take the long charging times necessary. Conversely, deep cycle batteries don’t have the cranking power necessary to start large engines time after time.Marine batteries can be split further, into three basic groups for both cranking and deep cycle batteries: standard flooded, or wet-cell batteries, are the most common. The battery’s six cells are open and contain the standard lead plates and electrolyte. You can service these batteries yourself.

 The second kind of marine battery is the “maintenance free,” or sealed battery, which does not allow access to the cells. The third kind of battery is comparatively new; it’s the “absorptive glass mat” battery that uses different plate and electrolyte technology. These are rated maintenance free, as well.

 Which battery technology?

 There are three basic kinds of technology used in building marine cranking and deep cycle batteries: wet-cell, maintenance-free and absorptive glass mat (AGM).

 There are advantages to each, and disadvantages, as well.Wet-cell batteries have significantly greater capacity than AGM batteries. They can be serviced, and additives such as Minn Kota’s Battery Equalizer can be added, as can distilled water. However, wet-cell batteries can spill acid if tipped over, and if improperly serviced, they can increase corrosion dramatically.Maintenance-free batteries are sealed and won’t spill. There is less corrosion, generally, with a maintenance-free battery because the electrolyte in the cells doesn’t get released unless there is a pressure buildup through overcharging. You can’t service maintenance-free batteries, except for cleaning the corrosion off the terminals, so when a cell gets low because of overcharging, it stays low.

 AGM batteries are maintenance free, and the internal structure is significantly different. They are much, much more resistant to vibration, according to Tom Kubasta, market and product manager for Optima batteries. The Optima, made by Johnson Controls, is 15 times more resistant to vibration than wet-cells.

 AGM batteries don’t spill, and have a slower rate of discharge as well as a quicker recharge. However, they also have a lower amp-hour rating.

 How to get the most out of your battery

 Getting good life out of your batteries requires one thing: maintenance. You need to pay attention to the condition of your batteries, whether they are maintenance free or not.

 Maintenance-free batteries do not require a lot of maintenance, but they do require some.

 The most important thing you can do is charge your batteries — regardless of type — as soon as you return from fishing. If you let batteries sit under partial charge for long periods of time, you will see a drop in their performance because of sulfation, and there will be a drop in the longevity of the batteries as well.

 Another source of battery failure is the buildup of sulfates on the plates of batteries.

As mentioned earlier, charging the battery returns sulfate on the plates to the electrolyte solution, but not all of it leaves the plates. Over time, the sulfates build, and it’s this buildup that increases internal resistance and resistance to charging.

 For wet-cell batteries, you can add a “cleansing agent,” such as Minn Kota’s Battery Equalizer (the only one with which I’m familiar), to each cell to remove sulfate buildup and thereby extend the life and capacity of the battery.

 The second-most important thing you can do is frequently check for the buildup of corrosion on the battery terminals. Corrosion will lead to partial charging, and it will also cause a break in the circuit, usually at the worst possible time.

 Corrosion is a result of electrolyte leakage when the battery is overfull, hot or overcharged. Corrosion also occurs when the battery emits gases during the charging process.

 Clean off the corrosion by using a solution of baking soda and water, a rag and a wire brush or sandpaper on the terminals. Coat the areas with electrolytic grease, such as Super Lube’s Anti-Corrosion Gel, when clean.

 Before you put the battery cable back on the terminal (or when you install a new battery), run a thin bead of silicone around the base of the battery post and install a felt battery washer. Coat everything with the grease to eliminate contact with the battery gas.

 On wet-cell or flooded-cell batteries, pop the cell caps and check the electrolyte levels before charging. Battery plates should be covered by 1/8 inch of fluid. The fluid level should not extend to the top of the cell, but should be approximately 1/4 inch below the splash ring on the mouth of the cell. The gap allows for expansion of the electrolyte when hot.If the cells are down, you will need to refill them, using distilled water. Take care not to fill directly out of the container of water, but slowly add it to the cell so you can judge levels accurately. Don’t overfill.

 Smart chargers

 The best insurance you can buy to extend both the life of your batteries as well as the power they provide is to use a multistage charger that delivers the power your batteries need at the different stages of charging. The new generation chargers won’t overcharge a battery and cause it to overheat or boil.

 Whether you opt for an onboard charger, which installs in the battery compartment of your boat, or a stand-alone model, be sure to choose the best you can afford. Here are few of the chargers available:

 The DuraCharge Tournament Series chargers are designed to keep batteries at peak power longer, so they can withstand the rigors of tournament competition. They feature A2A Equalization to clear sulfates from the positive plate and condition batteries for longer life, and they use microprocessor technology to fully charge batteries each time, even in harsh weather. (www.ampcon-power.com; 877-267-2608)

 The Guest Charge Pro 2745A onboard charger is designed to quickly charge trolling motor batteries. The company says the 45-amp charger (15 amps per output) will bring three trolling batteries from 60 percent discharge to full state-of-charge in four hours. The charger uses “intelligent” three-stage charging, so you can keep it hooked up indefinitely without worrying about boiling off elecrolytes. (www.marinco.com; 707-226-9600)

 The MK 220 and MK 330 chargers are the most advanced in the Minn Kota line. Like all smart chargers, they use microprocessors to assure the proper charge every time. They’re watertight and corrosion proof — important features for onboard models — and they provide on-demand equalization to prevent and reverse internal sulfation. The MK 330 offers multistage charging for three banks of batteries at 10 amps per bank, while the 220 is made for up to two batteries. (www.minnkotamotors.com; 800-299-2592)

 Several packaged bass boats come with MotorGuide Charging Systems installed. The Max-Pro II and III provide 15 amps of output per bank. They shut off automatically when batteries are fully charged and turn back on when a charge is needed. And, color coded leads help in installation and troubleshooting. (www.motorguide.com; 920-929-5040)

 Want to charge your trolling motor batteries while motoring from one fishing spot to another? The Stealth 1 Charging System can use either AC power (from an electrical outlet) or DC power (from your outboard) to charge up to six batteries at a time. Some pros report that their batteries are fully charged after a day of fishing and a short ride to the ramp. Stealth’s “Pulse” technology works on any battery and cleans the plates on marine batteries as it charges. (www.stealthcharging.com; 888-588-4506)

 Perhaps the valedictorian of the smart chargers goes to the Pro Series three-bank charger from Charging Systems International (CSI). Each bank has its own individual charger that analyzes batteries separately. This allows the charger to compensate for batteries in different stages of life: Older batteries need to be charged more often, while new batteries need less attention. The Pro Series also considers temperature, so batteries will receive a full charge no matter what the atmospheric conditions. The CSI chargers are waterproof and shut off completely when a battery reaches full charge, eliminating problems that occur with trickle-charge models. (www.dualpro.com; 800-742-2740)

 Power to the battery

 Charging is where a fisherman can make his greatest gains in extending the life and keeping the capacity of the battery high. First, you should always charge your battery fully when you return from a fishing trip. Letting a battery sit results in sulfate buildup on the plates, which may be difficult to remove. It’s important to fully charge the battery as well, to keep it at its highest levels. Partial charging will eventually lead to reduced capacity.

 When charging, open the top of wet-cell batteries to release heat buildup as well as to ease the off-gassing that will occur. Check fluid levels at the same time.

 To get the most from your battery, you need to measure the charge you’re giving by first checking the battery’s charge level. For instance, a 50 percent charge on a 100-amp battery means that the charger should provide 50 amps of charge. At a charge rate of 10 amps, that is a five hour charge. Too much time on the charger will damage the battery.

 An alternative to this kind of calculation (and its potential risk) is to use one of the new “smart” chargers. These chargers are multistage, and by checking the state of the battery during charging, they provide exactly the charge level needed to bring the battery up to its optimum level. When the battery is fully charged, smart chargers turn themselves into maintenance mode.

 There are a number of companies that make smart chargers: Minn Kota and MotorGuide are two I’m familiar with, and there are more than a dozen other manufacturers currently making onboard marine chargers.

 Battery safety

Any time you’re working on your batteries, you need to wear the proper protective gear. Safety glasses are a must for protection from both the electrolyte as well as the corrosive dust and particles that are released when cleaning the contacts.Long-sleeved shirts, long pants and even rubber gloves will give you an added measure of protection from the effects of the acid.You should charge batteries in a well-ventilated space, as hydrogen gas is given off in the charging process. Without ventilation (this is one reason to pop the tops off wet-cell batteries), you run the very real risk of an explosion.