Ever seen a grown man crying at the boat ramp? Chances are he has a dead battery! Not long ago “John” found himself in this very predicament, except for the crying part.
John had heard a certain trophy bass lake was “on fire” so he stocked up energy bars and water, and drove nearly two hours to the lake. While prepping to launch, John hit the motor’s trim switch and nothing happened! Rather than throw in the towel, he drove 30 minutes to the local Walmart and picked up a replacement starter battery. He installed it in the parking lot amidst shoppers and was back at the ramp quickly, but angry with himself for having to spend nearly $70 for his mistake.
Typically charged by the outboard alternator, starter batteries are pretty resilient, especially if there isn’t a lot of other electronic equipment drawing power.
After some time in the boat’s battery compartments tracing wires, he figured it out. The stereo was sucking the cranking battery dry. Even though it appeared off when not in use, the internal clock and memory functions were drawing power. He also noticed the onboard charger was a two-bank unit, dedicated solely to the two trolling motor batter-ies— not the trolling motor batteries and the starting battery. Even though he was plugging it in every night, the only time the starter battery was getting charged was when he was using the outboard. John later installed a separate switch between the stereo and battery and replaced his two-bank charger with a three-bank unit.
The lesson here? Know your chargers.
Battery manufacturers will tell you that the number one cause of marine battery failure is charging mistakes by anglers and boaters. Overcharging batteries can cause battery plates to boil off electrolytes; undercharging can clog battery plates with lead sulfite. Either way, you’re headed for excessive frustration without the correct charging set-up.
The solution? Proper charging. The first step is determining whether you need a portable or onboard charger. Depending on the type of boat engine(s), electronics and trolling motor(s) configuration on your boat, your needs will vary.
Match the charger to the type of batteries you’re using. Conventional wet-cell, gel and AGM batteries all have specific charging needs. So, it’s best to pay close attention to manufacturer specs and match the correct charger with your batteries.
If you fish with a small boat, a portable charger may work fine, but onboard chargers are the new standard for bass boats and larger multi-species rigs.
If you’re in the market for a portable charger, check out Minn Kota’s MK110P, an option for charging one conventional wet-cell battery. It offers one bank x 10 amps for a total of 10 amps of output for fast charging. Just connect the color-coded battery clips to the positive and negative terminals and let the charger do its work.
The unit’s multi-stage charging capabilities prevent overcharging or undercharging, so you don’t have to worry about the right settings—or shutting it off at a certain time. If you use two batteries, take a look at the MK210P. Since the two-bank charger delivers five amps per bank, expect twice as long charging time (10-12 hours). The new Optima Digital 1200 12-volt battery charger is another portable option for not only marine batteries—AGM and traditional wet-cell—but your truck battery, too. It’s definitely a set it and forget it charger.
The best part about onboard chargers is convenience. It’s as easy as pulling off the water and plugging into a standard 120-volt outlet. There’s no monitoring, no moving batteries, no hassle or fuss.
There are two basic types of onboard chargers: linear and multistage. Linear chargers are becoming a relic of the past as multi-stage chargers offer “smart” technologies that virtually eliminate user error. Linear chargers have the tendency to overcharge batteries, greatly reducing the battery life.
But today’s multi-stage chargers, like models from Bass Pro Shops, Cabela’s, Minn Kota, and Dual Pro, offer monitoring and protection to maximize your batteries’ life and long-term performance. By their design, they not only charge but maintain your battery’s charge. And unlike linear chargers, they don’t shut off when your battery charge reaches a certain level.
Next, determine the number of batteries you need to charge. Onboard multi-stage chargers are available in various bank configurations, the number of “banks” corresponding to the number of batteries you need to charge.
Rather than rely on the outboard to fully charge the starter battery, many anglers are moving toward three- and four-bank chargers to not only charge their 24- or 36-volt trolling motor battery systems but the starter battery as well.
And now for the $100,000 question: “How often should I charge my batteries?” The answer: After every time you use it.
It’s also beneficial to keep your boat’s batteries on a low-amp trickle charge during storage whether that’s long- or short trickle charge during storage whether that’s long- or shortterm— just plug it in when the boat isn’t being used. This will greatly extend your battery life. You may wonder if this will spike your monthly electrical bill? Since it’s merely maintaining the battery’s charge, there’s not a substantial current draw.