How Long Will My Boat Battery Last?

For many keen boaters out there, the next few winter months will drag painfully slowly, and all eyes will be on the spring. Not only does this indicate longer and warmer days, but more importantly, it indicates the start of boating season!

Boats, like anything else in life worth having, require a great deal of care and maintenance. Not only do you have to keep them clean, but you also need to maintain them as well. This is where getting your electrics in check with a good quality boat battery is so important.

The last thing you want is to head out to the water, only to find that the electrics on your boat have failed because the battery’s as flat as a pancake.

Understanding how long your boat’s battery will last is very important, as is sourcifng the right boat battery. To help you make the right choice, here’s a look at lithium boat batteries, and how long they typically last.

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Different Types of Boat Battery

Typically, boats will have two separate batteries, or battery banks. One will be for starting the boat’s engine, whereas the other(s) will run your boat’s other electrics. Some boats will even have a third set of batteries which power more powerful items on your boat, I.E the bow thrusters or the windlass for your anchor.

Boat batteries, however, are not created equal and there are different types of battery out there. It’s down to you to decide which is right for you. Some different examples of boat battery include the following:

Wet lead acid batteries

Wet lead acid batteries were once the norm on boats of a variety of shapes and sizes. Like all things in life however, times have changed and they are now starting to become outdated.

Wet lead acid batteries get their name from the fact that they have a liquid electrolyte inside them. They are inexpensive, easy to source, and can be useful as a last resort.

They are however, prone to leaking, heavy, need regular charging, and can die very quickly.

AGM batteries

AGM (Absorbed Glass Mat) batteries have a protective stranded glass mat over the battery plates, along with gel for the electrolyte part.

You can use these batteries as starter batteries, as well as for powering the other electronics on the boat. A gel-only battery however, can only be used for house applications on the boat.

These batteries have a longer life cycle than standard lead acid batteries, they don’t leak, and they have a longer lifespan.

The downside is the fact that they need to be charged regularly, and they are often heavier.

Lead carbon batteries

These batteries are rare, but not unheard of, in the boating world.

Lead carbon batteries feature a lead anode and a carbon composite cathode. They have a lower charge, are more reliable, are leak-proof, and last longer.

The main downside is the fact that you can’t use them as a starter motor, and they are big, clunky, and heavy. They are also harder to source because they’re rarer.

Lithium boat batteries

Finally, leaving the best until last, we have lithium boat batteries.

Lithium boat batteries come in a variety of different specs, though the lithium iron phosphate (LiFePO4) is one of the most popular.

Lithium batteries hold their charge very well, they have a longer lifespan, they’re lighter in weight than lead acid batteries and lead carbon batteries, and they are much more durable and can withstand more extreme temperatures and elements.

The only real downside is the fact that they’re pricier, but if you opt for a good quality battery, like those offered by MANLY, they will last longer and need replacing less, so overtime they work out cheaper.

How Long Will My Boat Battery Last?


How long your boat battery lasts will depend on a number of factors – namely, what kind of battery you have to begin with.

If for example, you have an outdated wet lead-acid battery, it is going to have a much shorter life expectancy than a brand new lithium ion battery from a reputable supplier such as MANLY Battery.

How long it lasts will depend on the quality, how often it’s in use, how well maintained it and your boat is, the conditions where your boat is, and much more besides.

To give you a very rough idea however, a standard lead-acid battery may last 3 – 6 years, whereas a lithium-ion battery can last 10 – 20 years with careful maintenance. 

Which Type of Boat Battery Lasts the Longest?

Okay, so suppose you’ve bought your boat and are in it for the long haul. You enjoy boating and you want to keep your boat for decades, or as long as possible. Which battery should you opt for?

In terms of longevity, by far, you would be best top opt for a LiFePO4 battery. Lithium Iron Phosphate batteries can potentially last more than 5 times longer than a standard lead-acid battery. That means that you could potentially get through five different lead acid batteries before you would even need to consider changing your lithium boat battery.

Can Lead-Acid Batteries be Replaced with Lithium-Ion Batteries?

It’s all well and good talking about how great lithium batteries are, but what about if your boat already has a fairly decent lead acid battery? Can you replace that with a better quality lithium battery? Well, the answer is yes.

In most instances, it is perfectly fine and perfectly simple to replace a lead acid battery with a lithium battery. Just be aware that some starter motor systems may be designed specifically for a specific type of battery, so before you change it, make sure a lithium battery would indeed work. Make sure that you do, otherwise you’ll create far more work and expense for yourself.

How Many Years Will My Lithium Boat Battery Last?

We’re not fortune tellers, and we can’t predict the future, so we can’t say for certain how long your lithium boat battery will last, because we don’t know.

As we looked at before, there are numerous things that will affect the lifespan of your battery, so we can’t say for certain how long a lithium battery will last.

What we can say for certain however, is the fact that lithium boat batteries last considerably longer than standard lead-acid batteries. One of the main benefits of a good quality lithium boat battery, such as the MANLY LiFePO4 battery, is their lifespan.

In optimal conditions, used correctly, and well maintained, you can potentially get 20 or more years out of a lithium boat battery. This means less expensive in the long run, and less hassle having to replace the battery every few years. 

Will My Lithium Boat Batteries Get Hot? 

Obviously when talking about batteries of any kind, there is always the concern that the batteries in question will get too hot. Not only can an overheating battery potentially burn you, it could also pose a fire risk as well.

While lithium boat batteries may get warm, they shouldn’t reach close to temperatures that would be of a concern.

It’s perfectly normal for your batteries to warm up when in use, but be wary of any extreme rises in temperature. Overcharging your batteries, or purchasing inferior products without the necessary safety features in place, puts them at risk of overheating. This is why you should always buy from a reputable supplier, such as MANLY Battery.

Do I Need a Special Charger for a Lithium Boat Battery?

When using lithium batteries on your boat, it’s important to ensure that you charge them correctly, and safely. This is where it proves to be so important to use the right kind of charger.

When charging a lithium boat battery, always make sure you charge it with the right designated charger. Don’t use a cheap aftermarket device, and try to use an old or outdated battery charger either.

Lithium battery chargers are designed specifically to be used with lithium batteries, fondly enough. They offer superior charging rates, they have in-built safety features, they provide optimal voltage levels, plus they’re reliable and very durable as well.

Put very simply however, only use the designated lithium battery charger to charge your lithium boat batteries.

Should I Upgrade to a Lithium Boat Battery?

As you can probably see, we’re very impressed with lithium boat batteries and if you have the opportunity to upgrade to a lithium boat battery, you should certainly do so.

Providing you buy from a reputable supplier such as MANLY Battery, lithium ion boat batteries offer a huge range of benefits when compared with lead acid batteries.

Not only are they lighter in weight so your boat moves quicker, and uses less fuel, they also last much longer, they hold their charge better, they’re more reliable, they discharge slower, and they have a number of in-built safety features.

So, should you upgrade to a lithium boat battery? Absolutely, and if she could, your boat would thank you for doing so.


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