The old saw says that “a ship is safe in harbor”…but that’s not always true.
If you’ve ever launched on a beautiful day, only to get out on the water to discover that you have a dead battery, then you know the importance of taking care of your batteries…which means storing your boat properly.
The ideal storage solution will protect your boat from extreme temperatures and also allow you to periodically check on the batteries. This could be in a dry slip at the marina or in a climate-controlled garage—both storage rental options available through peer-to-peer boat storage services like Neighbor.
With proper storage, boat batteries are generally good for 4 to 10 years.
There are several types of marine batteries, each with its own specifications and care guidelines. Let’s take a deeper look.
Factors Affecting Boat Battery Lifespan
While lead-acid batteries typically last for 2-5 years, lithium batteries can last up to 10 years or more.
Several factors influence the lifespan of marine batteries, including:
• Storage conditions
• Maintenance practices
• Battery type
• Frequency of usage
Storage Conditions
Storing your boat battery at the right temperature is crucial to its longevity and performance. Lead-acid batteries should be stored in temperatures ranging from 32-77°F and lithium batteries between 32-86°F.
Boats can be expensive to store, but if you live somewhere with icy winters, storage will definitely help preserve your battery health (not to mention your boat). You can ask at your local marina about storage options, or go online and look at affordable, peer-to-peer storage options.
Terminal Care
Maintaining clean and tight battery terminals prevents voltage loss and corrosion. You’ll want to regularly clean the terminals with a wire brush or cloth. You can also choose from several after-market products like sealants and fiber washers that keep your terminals clean.
Charging Techniques
During long periods of inactivity, it’s important to use trickle chargers or maintainers to ensure your marine batteries remain charged and in optimal condition.
One of the keys to extending your boat battery’s life is to use a quality charger and avoid overcharging or undercharging.
Advanced battery chargers are particularly beneficial for marine batteries, as they feature a multi-mode charging process tailored to the specific battery type. This helps prevent overcharging and sulfation (the gunk that sweats out of the battery heads), ultimately prolonging the battery’s lifespan.
Types of Boat Batteries
If you are obsessed with Teslas and happen to be ultra-wealthy, you can always look into the all-electric X-Shore: the “Tesla of the Sea”.
For the rest of us, off-the-shelf batteries work just fine.
Lead Acid Batteries
Lead-acid batteries, such as flooded lead acid batteries, gel, and AGM types, are a common choice for boats. These batteries have an expected lifespan of 2-5 years with adequate maintenance. However, running lead acid batteries all the way down can reduce their lifespan or make them inoperable.
It is crucial to properly maintain your lead-acid batteries, as inadequate upkeep can drastically impact their lifespan.
Lithium Batteries
The lithium cell battery remains the gold standard for long life and low maintenance.
Upgrading to lithium iron phosphate batteries, such as LiFePO4, can provide numerous advantages over lead-acid batteries. These benefits include a longer lifespan, increased efficiency, and minimal maintenance requirements. In fact, lithium boat batteries can last up to 10-20 years or even longer.
It is essential to use appropriate chargers for lithium batteries to avoid potential damage or reduced long-term performance. (In emergency situations, lead-acid battery chargers can be substituted for lithium batteries, but this should be avoided whenever possible to ensure the longevity and efficiency of your lithium battery.
Deep Cycle Batteries
Deep cycle batteries are specifically designed for continuous use and discharging, making them ideal for powering various onboard electronics and appliances. The lifespan of these batteries depends on factors such as battery type, usage, and maintenance.
To maximize the longevity of deep cycle batteries, you should consider a dual-battery electrical system. This system connects the cranking battery directly to the engine’s alternator and starter, while the deep-cycle battery is connected to the alternator through a DC-to-DC battery charge controller. This setup ensures proper charging and usage of the deep-cycle battery, helping to extend its life.
Troubleshooting Common Boat Battery Issues
Common issues include parasitic drain, battery swelling, and weak cranking power.
Parasitic Drain
Parasitic drain is a continuous electrical current drain that occurs when the ignition is turned off, resulting in a gradual loss of battery power. To identify and fix parasitic drain, it is necessary to disconnect the ground cables from the battery and measure the current with a voltage meter.
If the amperage is higher than expected, you’ll want to inspect for faulty electrical components or incorrectly installed aftermarket accessories.
Battery Swelling
Battery swelling occurs when a battery (typically lithium-ion) expands or bulges. Causes of battery swelling can include overcharging, overheating, or age. Swollen batteries pose a significant risk, as they can lead to short circuits, fires, and explosions.
If you notice your battery swelling, you need to remove and dispose of it in an appropriate manner to prevent potential risks.
Weak Cranking Power
Weak cranking power refers to the slow or sluggish rotation of the engine when attempting to start your boat. This can be caused by:
• a weak battery
• a defective starter
• inadequate charging
• problems with the control circuit or ground connections
To help prevent weak cranking power issues, you’ll want to regularly use a battery multimeter to check the battery voltage.
Understanding Boat Battery Types and Their Applications
Knowing the different types of boat batteries and their applications can help you make informed decisions when choosing the right battery for your vessel. The three major categories of boat batteries are starter batteries, house batteries, and trolling batteries.
Starter Batteries
Starter batteries are designed to provide short bursts of energy to turn over your boat’s engine. These batteries generally have a longer lifespan than deep-cycle batteries and it is recommended that you use AGM or gel batteries.
Starter batteries should never be used for deep-discharge applications, as they are not designed for this purpose.
House Batteries
House batteries are utilized to power the various electronics and systems aboard your boat, including navigation systems, heating and cooling systems, appliances, and other comfort-related items. The most common types of house batteries are lead-acid, lithium, and deep-cycle batteries.
Trolling Motor Batteries
Trolling motor batteries provide the necessary power to operate the trolling motors, which are used to keep the boat moving at a slow, consistent speed when you’re dropping some hooks in the water. These batteries typically have a life expectancy similar to house batteries.
Upgrading to Lithium Boat Batteries
The price sticker of lithium batteries causes many boat owners to pause. But upgrading to lithium boat batteries offers several advantages over traditional lead-acid batteries. These benefits include cost-effectiveness, compatibility with existing systems, and a longer lifespan.
Cost-Effectiveness
While lithium boat batteries may have a higher upfront cost compared to lead-acid batteries, their longer lifespan and lower maintenance requirements make them a cost-effective choice in the long run. Lithium batteries can last up to three times longer than lead-acid batteries, providing boat owners with cost savings and convenience over time.
Compatibility
Most lithium boat batteries are compatible with existing systems, making the upgrade process relatively simple and hassle-free. For example, lithium boat batteries can be used with various trolling motors and connected in series to power a 36V trolling motor.
Frequently Asked Questions
How do I know if my boat battery needs replacing?
If the voltage test of your marine battery shows zero volts, it’s a fair bet that it has died and needs to be replaced!
Any reading under 12.4 volts should warrant further investigation and likely a replacement battery.
How long does a 12-volt deep-cycle marine battery last?
Depending on use, a 12-volt marine starting battery typically lasts between 5 and 10 years. Lead-acid batteries are known to perform well in this regard.
How long can a marine battery sit before it dies?
A lead-acid marine battery can generally sit unused for 6 to 12 months, depending on the conditions.
However, boat batteries can die if left dormant for months at a time.
Can a boat battery last 10 years?
The right type of battery can last 10 years or more. (This will, of course, depend on the number of charging cycles, and how often it gets used.)
Proper care and maintenance of a boat battery is essential to its longevity. Regularly checking the battery’s charge level, cleaning the terminals, and storing it in a cool, dry place can help extend its life. It’s also important to use the right type of charger, and avoid overcharging.
How do you charge a deep-cycle battery?
To charge a deep cycle battery, first, clean the terminals, then connect the red (positive) cable to the red terminal and the black (negative) cable to the black terminal. Plug in the charger. Yup, just like any other battery.
If using a smart charger, you can “set it and forget it” before disconnecting.
Before you Launch
With the push toward EV cars, battery technology is rapidly increasing. In the future, it’s possible that we will have super-batteries that will go seemingly forever, and require almost no maintenance.
Until that time, you’ll want to practice good battery hygiene to keep your vessel launch-ready. Find good storage for your boat, keep the battery terminals and connections clean, and use a multimeter to check your battery health.
And if it’s going to be several months, don’t forget the tickle charger: it runs just enough current to keep your batteries juiced up for your next adventure on the water.
