6 Ways Your Boat Batteries Fail

Here are the most common modes of failure for marine batteries, and what you can do to avoid them.

1. Overheating and Extreme Cold

Although marine batteries are designed to stand up to rugged use, they are more susceptible to temperature fluctuations than many owners may realize. During extremely hot temperatures, batteries tend to expand and push out energy at a higher-than-normal rate. High temperatures can result in electrolyte loss and increased discharge.

In frigid temperatures, the opposite tends to be true. Cold temperatures force the battery to work harder, and the result may be a lower discharge rate. Either way, your unit suffers an undue strain that may shorten its lifespan.

What to Do: Keep our marine battery in a controlled environment whenever possible. If your boat is in a dry dock during extreme weather, make sure the battery is housed in a moderate temperature environment.

2. Improper Charging

Marine batteries may appear to be a universal type of commercial product, but they require very specific charging profiles and maintenance. One of the areas that some marine battery owners inadvertently damage the products is during that recharging phase.

Each battery has its own recharging specifications. Putting yours on overly high voltage for a quick charge is likely to cause an early end to the service life. High voltages cause sulfation, which is when the internal plates to displace the elements that make them uniquely powerful. High voltages also speed up corrosion and faster discharge rates.

What to Do: Follow the charging guidelines provided by the manufacturer. Adhere to the required voltage and do not overcharge the unit. Installing a quality onboard charger is the best practice for getting the longest service life and best performance from flooded and AGM marine batteries alike.

3. Sulfation of the Cells

While counterintuitive, it is not uncommon for flooded batteries to falter earlier than expected due to underuse. When lead-acid batteries discharge less than 30 per cent of their capacity, acid tends to accumulate in the form of sulphate crystals on the lead plates.

This build-up can significantly inhibit the unit’s performance. What may be even more strange is that the battery shows no noticeable effects and can function well enough until untimely needs early replacement.

What to Do: Work with a marine charger that has an equalization option that ramps up the voltage at least once per year. This will help disperse sulphate crystal build-up and improve battery life.

4. Poor Long-Term Storage Practices

Some may remember when storing a battery on a garage floor spelled ruin. While those days are over, storage remains a key issue to long-term battery health. Storing batteries that are not clean can lead to unnecessary corrosion. Storing them when they are not fully charged can cause them to lose the ability to fully recharge later.

As noted above, the temperature can play a role in battery life. If you live in a cold climate, store your batteries indoors, hooked up to a battery minder to keep them topped off.

What to Do: When storing a battery over several months, be certain that it has been adequately cleaned and maintains a full charge. Store marine batteries in dry, temperature-controlled environments for best results come springtime.

5. Using the Wrong Battery Type for the Application

Many batteries may appear similar, but they are not necessarily designed for interchangeable use. Marine batteries fall into several applications because the demands placed on them differ greatly. Using a battery for general purposes or in the wrong application can have a negative impact on its lifespan. A deep cycle vs cranking battery for trolling motors, for example, are worlds apart.

What to Do: When choosing a marine battery, it’s important to set up a new boating system with the best battery for each application. Replace all the batteries at one time so they are matched, for best performance. Do not mix AGM and flooded batteries in a parallel configuration, such as a trolling motor.

6. Improper Installation

One sneaky mode of failure is poor installation, which can lead to acid leaks, fire, and even a battery explosion. In a less frightening sense, things such as loose cables or poorly maintained posts can reduce a batteries life expectancy.

What to Do: Mount the batteries in a properly sized battery tray, check your group size and compare to the battery tray and use straps to prevent sliding around in the compartment. Use cable boots and nuts to secure the power leads to the battery terminals.