Just like your boat and motor, your marine battery requires proper care in order to perform well and provide years of service. Such care does not require a great deal of effort, but a little maintenance and proper storage can give big payoffs in protecting a vital part of your boating investment.

“A good marine battery should provide about five years of strong engine starts and power to run a boat’s electronic accessories,” said Dan Ostrosky, an engineer at Yamaha Outboards.

“However, even new, well-built batteries can have their lives cut short if they are not checked periodically and stored correctly.”

Proper battery care includes maintaining a proper acid level. It is normal for batteries to lose some fluid during use, but if the acid level becomes too low, metallic plate oxidation can occur, and that can hinder the battery’s performance and shorten its life.

“To prevent metallic oxidation, check the acid level every month. If it’s too low, add some water. Make sure to add distilled water and not tap water,” Ostrosky said.

To provide maximum life, batteries should also remain fully charged while in use. This can sometimes be difficult if using a battery to run electronic accessories or if using more than one battery at once. One way to ensure batteries remain charged under these conditions is to use an engine with an adequate charging system.

“A good engine will generate plenty of power for batteries not only at full throttle, but at mid- throttle and trolling speeds. Yamaha’s V6 outboards, for example, feature a High Output three- phase Charging System that produces 20 amps at idle, 25 amps at 1,000 rpm and 35 amps at 5,500 rpm so batteries stay fully-charged at all speeds, even with multiple electronic accessories up and running,” Ostrosky said.

Yamaha V6 outboards, such as those in its popular V Max and Saltwater Series, also solve the problem of monitoring multiple batteries with Yamaha’s exclusive Multi-charge Monitoring System.

While the engine is running, the system charges the weakest battery to recovery, then charges all batteries equally, preventing one battery from turning off the system before the other battery recovers.

The system also separates the starting battery from the accessory battery when the engine is off, ensuring that the starting battery retains enough power to get the engine going again.

If your charging system works fine, yet the battery remains undercharged, test the acid strength with a hydrometer. If, like most boaters, you do not have a hydrometer, have a marine dealer perform the test for you.

Proper storage can also increase the life of a battery. “Whenever your battery sits idle for more than a month, remove it from the boat and place it in a warm, dry area. If your garage has a concrete floor, place the battery on a piece of wood to keep it insulated from the cold ground,” Ostrosky said.

Batteries should remain fully charged while in storage. To do this, trickle charge the battery every month for 12-24 hours at 10 percent of its amp/hour rating. For example, a battery with an 80 amp/hour rating should be trickle charged at no more than 8 amp/hours.