Marine batteries are specially designed for use on board, with a heavy steel plate and strong construction to withstand the shocks and shocks that can occur in any powered boat. For this reason, marine batteries are generally more expensive than car batteries, which may tempt some boat owners to buy car batteries instead of marine batteries. Don't make that bad decision. Compared to car batteries, marine batteries last longer and perform more reliably.
(1) Marine starting battery. Provides a quick but powerful injection of energy for a short period of time to start the engine and charge quickly via the engine alternator. The starting battery cannot be used for traction motors or to power appliances.
(2) Marine deep cycle batteries. Designed for slow discharge over long periods of time and can withstand hundreds of charge-discharge cycles. Deep cycle batteries are the right choice to drive electric tug motors and other battery powered accessories such as audio systems, windlasses, echo sounders, fish locators and other equipment. A deep cycle battery is not a substitute for a starter battery.
(3) The dual purpose boat battery. Combined with the performance of a starting and deep cycle battery, it is a great option when small and there is no room for two batteries. While they can perform the tasks of starting batteries and deep-cycling batteries, they are not as efficient as individual batteries.
Most of us know that when we buy a new or used boat, the battery on offer doesn't have to be top notch. If they seem to be up to the job, we don't give them too much thought. But in warmer climates, daily heat is the main enemy of batteries and can drastically shorten their lifespan. In regions that force us to store our boats for the winter, how the batteries are maintained during this time is also critical to prolonging life.
It's best to put the boat battery on a regular "trickle" charger and keep it charged when not in use. A battery that is not charging (or has been charging) can freeze at low temperatures, and the result is likely to rupture the battery case. Batteries are like many things in life - use it or lose it! Car batteries usually last longer than yacht batteries because the car is constantly used and the battery stays charged.