Marine Battery Maintenance – A Guide

Do marine batteries need maintenance? Marine battery maintenance is crucial for the proper functioning of any boat. A well-maintained battery is vital to ensure safety whilst out on the water. So, as warmer weather beckons, many will be getting boats ready to hit the open waters and inland canals; we’ve put together a guide on marine battery maintenance and answered the most commonly asked questions that we encounter regularly, to help boat owners keep their batteries in the best condition.

 

Our steps for Marine Battery Maintenance

 

Here’s our guide to marine battery maintenance, these tips should help you avoid regular costly battery repairs or having to replace the battery often. 

 

1. Store Your Marine Battery Correctly

 

Firstly, you must ensure that when you are storing your battery that you are doing so correctly. This is important to ensure the longevity of your marine battery life.

Should you disconnect your boat battery when storing your boat? Ideally yes, you should remove the battery from the boat and place it in a cool, dry location to ensure it is safe and kept in the best condition. If you are planning on storing the battery for an extended period, it’s advisable to charge it fully beforehand this helps increase the battery’s lifespan. Leaving your marine battery outside over winter leaves it exposed to potential damage from the cold weather and meaning you may have extra maintenance for when you get your boat out in the spring.

 

2. Clean Your Battery

 

However you choose to store your marine battery over winter, the first thing you will need to do when getting it out is to give the battery a good clean. You can do this by spraying a small amount of WD40 onto an old rag and going over the entirety of the battery or mixing a solution of baking soda and water. Pay close attention to the terminals and ensure they’re clear of any dust or debris, see pictured a marine battery in desperate need of cleaning.

 

 

3. 3. Check the Battery’s Charge Level

 

Check the battery’s charge level, your marine battery voltage should be between 12.7 to 12.8 volts. If your battery voltage is below 12.4 volts, use a specialist battery charger to charge the battery. BBL Batteries have a range of battery chargers available and ready for purchase here, if you are unsure of which you will need for your marine battery or want advice on how to use the charger we are happy to answer any of your questions.

Check your battery’s voltage after a few hours of charging to see if the battery is accepting the charge. Once it’s at a healthy voltage, remove it from the charger and test again after 12 hours to see if the charge is being held. If the charge has dropped, this may indicate you may have a faulty battery. If in any doubt bring your battery to a BBL Batteries branch where it will be professionally tested and checked over. To check your marine battery yourself you can purchase one of our multimeters pictured below.

 

If you have a traditional lead acid battery you will also need to check the battery’s electrolyte levels and top up if required; you will not have to do this if you have an AGM, Gel or Lithium battery. 

 

 

3. 3. 4.  Inspect the Battery for Any Damage

 

Before using your marine battery, you must check for any damage. Look for any cracks or leaks in the battery case that could have happened in storage. If the battery is damaged in any way, it should be replaced.

 

 

3. 3. 5. Use the right type of battery for your boat

 

Using the correct type of battery is essential for the proper functioning of your boat’s electrical system. Similar to leisure batteries there are many ‘technology’ options available for marine batteries; from the latest lithium technology to the more traditional deep cycle batteries and AGM (Absorbed Glass Matt) marine batteries so the maintenance does vary depending on your battery type. Contact our team of experts for advice on which marine battery is right for you.

 

 

3. 3. 6. Coat the Battery Terminals

 

Before returning the battery to the boat, coat the terminals with grease, lubricant or even Vaseline; this will help to protect the terminals and help to strengthen the electrical connection. 

 

 

3. 3. 7. Refit your battery!

 

Refit your battery in your boat and enjoy!

 

Frequently Asked Marine Battery Questions

 

How long does a Marine Battery Last?

Several factors could affect the lifespan of a marine battery, what type of battery you have, how you use it and how well you maintain it. Generally speaking, a marine battery can last anywhere from 1 to 6 years, and some high-quality batteries last even longer.

Lead-acid batteries are the most common type of marine battery and they typically last between 3 and 5 years, this can however vary depending on the usage and maintenance. Gel batteries and AGM (Absorbed Glass Mat) batteries are also available and have a longer lifespan, lasting anywhere up to 7 years or more with proper maintenance. BBL Batteries stock a wide range of marine batteries covering all technologies and brands, ask a member of our team if you’re unsure of which would suit you or shop here!

 

Are dual-purpose marine batteries good?

Dual-purpose marine batteries can be a good choice depending on your needs and planned usage. They are designed to provide both starting power and deep cycling capabilities, meaning they are a popular choice among boaters as they can handle both turning the engine over and powering any onboard electrical equipment, essentially a two-in-one battery. They are also generally less costly and more compact and lighter than traditional deep-cycle batteries, meaning they are easier to install and manoeuvre on boats with limited space. However, they are not a good choice for any boaters that run high-powered electronics for extended periods or those with a larger boat as a larger engine may require more starting power.

 

How often should you add water to a marine battery?

How often you should add water to your battery depends on the type of battery you have and how often you use it. We recommend checking the water level at least once a month, or after every use, to ensure that the water level is within the manufacturer’s recommended range.

 

Should I charge my marine battery after every use?

Yes, it is a good idea to charge your marine battery after every use, especially if it has been discharged significantly. Lead-acid batteries, which are the most common type of marine battery, can be damaged if they are allowed to remain discharged for an extended period. By charging your marine battery after every use, you help prevent this hardening of lead sulfate and extend the battery’s lifespan. It’s also important to keep in mind that if the battery is not fully charged, it may not have enough power to start the engine or power onboard equipment on your next outing. Dual-purpose or deep-cycle marine batteries may not need as much charging, you should consult the manufacturer’s recommendations of how often your battery will need charging.

 

How long can a marine battery sit before it dies?

Again, this depends on the type of battery, its age and the temperature at which you store it. A fully charged lead-acid marine battery can sit unused for around 6 to 12 months, depending on the conditions. If the battery is not fully charged when it’s stored, its lifespan can be significantly reduced. If a battery is stored in a warm location, it may lose its charge quicker than if it were stored in a cooler location.  If a battery is not charged and maintained regularly, this can lead to decreased performance and a shorter lifespan. 

 

Can you overcharge a marine battery?

Short answer, yes, you can overcharge a marine battery. This can cause a lot of damage. Excessive heat and gas could build up inside which can not only damage the battery and the surrounding equipment. Thankfully most new marine battery chargers have an automatic shut-off feature that prevents overcharging. Make sure that you use a charger that is designed for your specific battery type and size and follow any recommendations for charging. If you are using a manual charger, monitor the battery’s voltage and current throughout the charging process to avoid overcharging. 

Following these tips on how to properly maintain your marine battery is crucial to ensure your boat functions properly. Regular maintenance can help prevent costly repairs and ensure a safe and enjoyable boating experience.

 

For more information about marine batteries, for advice or to place an order, please contact your local friendly team of battery experts.

Bristol 0117 9550535 | Swindon 01793 616646 | Truro 01872 270011 | Exeter 01392 254418 | Plymouth 01752 338501