The increased use of lithium-ion chemistry batteries on land has had a parallel trend in the marine world. Lithium-ion batteries, which were considered highly exotic five years ago, are becoming ever more commonplace on voyaging boats. What are the reasons for this trend and how widespread is it? The longtime king of marine batteries, of course, is the lead acid cell. Using a liquid electrolyte and lead plates, each of which is a matrix generally filled with soft lead, the wet cell marine battery ruled supreme for its stability and its storage capacity. Different types of wet cell units were…