Batteries that have liquid electrolyte sloshing around in them are sometimes referred to as 'wet', 'flooded' or 'wet lead acid' batteries. To start the engine, boats have a starting or 'cranking' battery, like those used in cars, which delivers very high loads for a few seconds. Only a small portion of the battery's capacity is used. An 'in-between' option is the 'dual' or leisure battery. A compromise between starting and deep-cycle batteries, these are popular on boats that carry only a single battery, or prefer to. Nobody wants battery acid leaking into the bilge, but there's a price to pay if you want more durable batteries. Sealed lead acid batteries are sometimes referred to as VRLA (valve regulated lead acid) and there are two main types –. Lithium-ion is a broad chemistry of batteries, the most common being LiFePO4 (Lithium Iron Phosphate). They can withstand four or five times the number of cycles compared to most deep-cycle lead acid batteries. Lead carbon batteries are not widely known. Our electrician had never fitted them, and indeed I hadn't considered these until I spoke to.
