Boat Battery

Boat Battery

It is summer time again; time to get out the boat, RV and maybe the four-wheeler for a little rest and relaxation. It is also the time of year that many people will be in the market for a new boat battery. Batteries that sit all winter long without being used have a propensity for dyeing, never to be revived again. That means it is off to the hardware or marine sales shop to get a new boat battery.

There are a few things you will want to consider prior to purchasing a battery. First is the purpose you for which the battery will be used and second are the different types.

Starting

A cranking battery is the one that is used to start your boat engine. Once the engine is running, the alternator replenishes the battery charge. This kind of boat battery requires maximum power in short bursts.

These batteries are categorized by marine cranking amps, MCA or cranking amp. With newer boats that have many sensors, pumps or gauges you will need more MCA/CA. Check your boats user guide for specifications.

Deep Cycle

The other type of battery is a deep cycle; it is used to power things like trolling motors. A trolling motor takes less out of a battery over an extended period and there is no charging system in place, users charge them at the end of the day instead.

This kind of boat battery is measured by reserve capacity, RC, which indicates how long the battery will last before dying. The higher the RC number the longer the battery will power accessories.

Types of Boat Battery

The next thing you must consider is the type of battery that will best suit the purposes outlined above. There are three battery types gel, absorbed glass mat or AGM and wet cell.

• Gel- A gel cell battery has many uses including use as a boat battery. These deep cycle batteries are completely sealed for increased safety. Inside the battery is a thickening agent similar to fumed silica that immobilizes the electrolytes. This means if the battery is ever cracked, it will continue to function.  The problem with gel cell batteries is price and vulnerability. They are generally higher than wet cell or AGM and are vulnerable to vibration common in boats.
• AGM- Absorbed glass mat batteries with a matting that is coated in electrolyte. Since these are also sealed batteries, there is no chance of acid or harmful fumes escaping. AGM batteries can be mounted at any angle and are resistant to damage from vibration. They are a bit more expensive than wet cells however.
• Wet Cell- This is the most common battery known to man, they are used in all kinds of vehicles, cars, trucks and boats. They contain distilled water and sulfuric acid. Wet cell batteries tend to have a longer life span, are cheaper, and weigh less than the other two types of batteries. The downside is the risk of acid spillage and the release of harmful fumes.

Bottom Line

Choosing a boat battery is more involved than running to the parts store and grabbing the first one you see. Do your homework and most importantly look at your boat or accessories manufacturers guidelines. They should contain the best battery for your particular boat.