Why install a marine battery charger?

Apr 10, 2017 Boat Maintenance ,Technology

On-board battery chargers or inverter-chargers are quite usual in larger vessels, but they are now becoming increasingly common in smaller vessels too, including trailer boats.

As small boats become ever more complex, the demands on the vessel’s electrical supply system increase. Boating magazine’s Haines Hunter 660 has a full complement of marine electronics, a Fusion entertainment system, LED lighting, an electric capstan and numerous pumps, all fed by a sealed lead-acid battery that also cranks over the 200hp Yamaha outboard at start up.

Depending on their size, engine alternators may struggle to keep batteries fully charged, especially if the boat is only run for short periods at a time and/or fitted with lots of power-hungry electrical gear.

Even if there is ample alternator power, as BEP Marine/ProMariner’s Liam McIlveen pointed out, shutting down the engine before switching off the sonar (stereo/Radar/bilge pump, lights or any other electrical item), or using the power tilt, bilge pump or any other electrical device, draws current from the battery, which is then left in a partially discharged state.

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In addition, alternators only produce their full charging output at somewhere near maximum engine revolutions, so if you idle around for long periods with your electronics going, there’s the chance the battery is being discharged faster than the alternator can top it up. It’s even worse when you switch the engine off entirely.

A lead-acid battery of any type is a consumable item and has a finite lifespan. Every time it is used its lifespan is slightly reduced. Under ideal conditions batteries age at a natural rate, but poor battery maintenance can greatly accelerate the ageing process. A battery that lasted only a year, rather than five years (or more, depending on the battery’s technology), is not faulty, but has simply aged more quickly.

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Batteries are expensive, so to protect your financial interest, it makes sense to slow the ageing process as much as possible. There are many factors that accelerate this aging, most of which can be avoided.

One such factor is storing a battery in a discharged state. This will decrease the batteries amp-hour capacity, reducing the length of time it can supply your boat’s electrical needs. The situation gets worse every time the battery is stored in a partially charged state.

Long term storage is another issue for boaters. Sometimes boats lie unused for many months and even if the batteries are fully charged to begin with, they self-discharge over time and so require a top up charge every now and then.

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The solution is to hook your boat’s batteries to a modern multi-program battery charger whenever the boat is not in use. The most convenient way to do that is to permanently mount the charger somewhere in the boat. Then, when you get the boat home, it’s simply a matter of grabbing an extension lead and plugging it in to mains power.

A decent modern marine battery charger will take good care of your battery’s health, charging, conditioning and keeping it topped up so there are no nasty surprises next time you use the boat.

ProSport6 on-board battery charger

ProMariner’s ProSport6 is one such modern charger, packed with the latest features designed to extend battery life and promote safer boating. So when Boating was offered one to try, it jumped at the chance.

ProMariner’s Tim Coates installed a ProSport6 in Boating New Zealand’s Haines Hunter 660 photo boat while the boat was undergoing routine maintenance at Seacraft Miller-Moyes Ellerslie facility. Tim also demonstrated some of the unit’s features.

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ProMariner’s ProSport6 features an all-digital micro-processor control and software controlled pulse charging technology. As soon as Tim hooked the supplied pre-wired cabling to the boat’s electrical system, the ProSport6 gave him automatic installation feedback for the whole charging/electrical system.

LED indicators monitor the health of individual batteries, clearly displaying that either all system and battery connections are okay, or that a fault is present on a specific battery bank.

Our Haines’ battery checked out in good health.

ProSport incorporates Distributed-On-Demand Charging technology, taking 100 percent of the available charging amps and distributing them to any one or any combination of battery banks as needed for faster charging.

In our case, we chose a single bank unit as there’s only one battery to look after, but if there are two or more battery banks on the boat, the multi-battery bank units can supply all the rated current to the battery bank that needs it most, or share the rated current between its outputs.

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For example, your house bank may be heavily discharged but the start bank is only slightly discharged. The charger would supply the rated current to both banks but as the start battery bank became full and its current demand fell, the charger would then deliver the full rated current to the house bank.

The compact, lightweight ProSport6 is 100 percent waterproof and saltwater tested. It’s shockproof and it’s rugged aluminium casing is designed to withstand the marine environment. The unit can be fixed to the vessel anywhere close to the batteries.  On the Haines, we bolted it to piece of Starboard which was then glued to the rear surface of the starboard transom locker next to the battery.

Built-in safety features include dual in-line DC overload safety fuses, built-in over-voltage, overload and over temperature protection, along with reverse polarity and ignition protection. Tim installed and tested the unit in a matter of minutes.

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Energy Saver mode monitors and automatically maintains the batteries at full charge only as required, saving AC power. If the boat is in long term storage, batteries are automatically reconditioned once a month.

Safer with longer battery life

A battery charger/conditioner permanently mounted in your trailer boat, yacht or cabin cruiser ready to be connected to mains power during those times your vessel is idle is a fine idea. That way your batteries are always fully charged when you want to use the boat, there’s far less likelihood of battery failure due to insufficient charge while out on the water, and if you’ve selected a charger that monitors and conditions your batteries as well as topping them up, you can expect extended battery life, which is easier on your pocket in the long run.