About your Starting Marine Battery
Your marine battery stores electricity chemically (Acid & lead). It is easiest to think of it as a power tank. The battery releases that electricity quickly to start the motor when you start the engines. In smaller boats, these batteries also run all the electronics on the craft, which drains the power tank. To safely start the engines the batteries should be sized correctly and 80%. Once the engine is started, your craft's battery is recharged by the engine-driven charging system or alternator at 2000rpm. The alternator changes energy from the engine into electricity, and forces it into the battery, where it is stored chemically.
Some boats have a generator or a secondary charging system. So if a battery is discharged, i.e. the lights are left on, it must be recharged by either the generator, the alternator, or shore power to be restored to full capacity.
SLI batteries are predominantly used for engine starting, vehicle drive lighting (i.e. headlights), and nominal loads for navigational electronics. The batteries below are sized in both cranking amps, and AH so you can determine your best fit.
The marine batteries below are Military Spec, Made in the USA, Lifeline Batteries. Our choice for premium batteries, supported by a laundry list of OEMs.