Marine Batteries

Marine batteries

Whether you’re primarily interested in marine batteries to start your boat’s motor or run a modern suite of comfort electronics while aboard, a good boating experience demands a top-quality marine battery. As you’ll be replacing even the best quality boat battery every 4-6 years, you’ll need to know exactly what to buy when the time comes.

Do I need a ‘starter’, ‘dual purpose’ or ‘leisure’ marine battery?

Starter boat batteries are primarily designed to start your engine, and to be recharged slowly as the engine runs. They deliver a great deal of power quickly, but might be less efficient at running low-power electronics and appliances. By contrast, a leisure or deep cycle marine battery is m ore efficient at delivering a smaller charge over a longer period.

Many larger boats and leisure craft use a back of different batteries, and can accept both a crank and a deep cycle marine battery at the same time. A dual purpose boat battery is designed to do both jobs reasonably well, but works in a smaller boat which only uses a single battery at a time.

What is the difference between Lithium Iron Phosphate, AGM, Gel and Flooded boat batteries??

Lithium Iron Phosphate marine batteries are a very new technology. They can be a bit pricy compared to other types, but offer a very long live, often between 2500 and 4000 cycles. They can be safely discharged up to around 90% (compared to 80% at best for most other technologies). They also tend to be smaller and lighter than other types of batteries at the same performance level.

In the end, even with the higher purchase price, Lithium iron phosphate marine batteries generally offer a lower cost per cycle, as they will outlast the other types by a wide margin.

Absorbed Gas Mat (AGM) boat batteries separate the battery’s positive and negative electrical plates with a glass matt saturated with an electrolyte solution. They are low maintenance, resist shock very well compared to other marine battery types. They tend to offer both greater starting power and faster charging than other types as well.

AGM batteries often find use as dual-purpose marine batteries because of their excellent all-around performance.

Gel marine batteries rely on a thick, largely leak-proof gel of acids, water and silica. They are therefore much lower maintenance than a flooded type battery, and are especially useful if the battery ever has to be inverted or laid on its side for extended periods. However, you must be careful to charge AGM batteries at a lower voltage than other marine battery types.

Gel batteries can excel at either the crank or deep cycle boat battery roles, depending on how they are constructed.

Flooded boat batteries are one of the oldest types of battery technology used on boats and leisure craft today, but they are still one of the most common due to their low cost and simple construction. They are called ‘flooded’ because they lay a series of lead plates in a bath of sulphuric acid to produce power. Recharging the batteries produces both oxygen and hydrogen by breaking down the water that dilutes the acid, so many require periodic top-ups with distilled water. They also self-discharge at a higher rate than other types, so they must be charged after moderate periods of disuse. They must also be used in a completely upright position, which can be difficult to manage aboard a boat.

Flooded boat batteries make excellent crank batteries and reasonably good all-arounders. They also handle overcharging better than any other battery type.

We offer a wide range of marine batteries, including both starter batteries and ‘leisure’ or ‘supply’ batteries. Please take a look, and feel free to filter our selection by price, brand, capacity or a range of other qualifiers.