Join date: Nov 18, 2022


How to know if your marine battery needs to be replaced

The biggest signs you need to replace your marine batteries deep cycle are if your motor won’t start, your onboard electronics don’t work, there’s visible damage on your battery, or your battery reads below 12.4 volts at a full charge.

Marine batteries experience a rough life as harsh waves constantly bash them around. So make sure to check the battery every once in a while for damages or any loosened connections. Always immediately replace a battery, battery wires, or battery terminals if they are damaged to avoid possible disaster.

If you check your marine battery’s voltage, it should read at 12.6-12.8 volts at a full charge. So if you want to maintain top performance out of your batteries, change them when they read below 12.6 volts. However, they should still work fine between 12.4-12.6 volts; they’re just more susceptible to randomly not working out at sea.

Most boats will give you a warning if your battery voltage is low. However, it’s best to know that before you go out on the water.

Another reason boat batteries are dying is dirt. Dirt and debris on the top of your battery and the terminals can become carbonized and drain your battery life. This causes your battery to discharge and recharge more frequently, shortening its lifespan.

So at the bare minimum, make sure to clean off the top of your battery (including its terminals) with a rag every other week or so. I also recommend using a battery cleaner aerosol such as this one here on Amazon as well.

Keep the battery out of extreme temperatures

Extreme temperatures can cause corrosion, water evaporation, and many other problems that reduce your battery’s lifespan.

Anything less than -4°F (-20°C) and over 113°F (45°C) is considered too extreme for marine batteries. However, it would be best if you never stored your battery anywhere below 32°F (0°C) or over 100°F (38°C).

The recommended temperature for storing a marine battery is 59°F (15°C). Any temp plus or minus 20 of that should be fine.

Wet cell (flooded) batteries are the most affected by extreme temperatures as the liquid inside can freeze/evaporate because of temperatures. Gel cell batteries are also greatly affected. AGM and lithium batteries can handle temperature better, but they can still be damaged if the temperature is extreme.

Always maintain a full charge to avoid sulfation

Sulfation is the buildup of lead sulfate crystals inside lead-acid batteries (it doesn’t happen in lithium batteries). This is bad because as the sulfate crystals build up more and more, your battery capacity will shrink smaller and smaller and eventually die.

You usually cannot see sulfation as it happens inside the battery, but if it gets bad, it may look like this around the terminals:

Sulfation is the leading cause of early battery failure in lead-acid batteries. All lead-acid batteries will experience some sulfation, but you can easily limit it by maintaining a full charge.

Not only do you need to keep your battery fully charged to avoid bad sulfation, but you also need to avoid undercharging, extreme temperatures, and extreme discharge. So essentially, just follow all of the other tips to avoid sulfation.

Getting a battery desulfator such as this one on Amazon will reverse some sulfation in your battery and help prevent any future sulfation. I highly recommend getting it to extend the life of your battery.

Tina Yu

Tina Yu

More actions