A boat’s batteries start the engine(s) and run the bilge pumps, so their vitality seems obvious. And yet how many of us can say we’ve done the best job possible of securing and caring for our batteries? And how many builders provide the proper environment for a battery right out of the factory?

We took a look at a group of boats — ranging from new to a couple years old — to identify some excellent and less-than-ideal setups. These simple guidelines serve as the backbone of our evaluation. …