How Long Will a Marine Battery Last?
For the purposes of this blog, when we answer the question of how long a marine battery will last, we are talking lifespan, not how long will it deliver power in a day. The latter question varies, depending on the boat the battery is being used in and how it is being used. The former question relates more to lifespan, which has more commonality across applications.
Some battery brands may offer warranties of ten years or more, suggesting their batteries will last that long. However, the reality in many of those warranties, is that the warranty becomes pro-rated within the first few years, so consumers end up paying for a warranty replacement, often at or above the brand's own cost. OPTIMA's warranty terms have no pro-ration, so when you buy a battery from us, if it needs replacement under warranty, the replacement is free.
Generally speaking, there are three types of marine battery chemistries commonly in use today- flooded lead-acid, AGM lead-acid (like OPTIMA's BLUETOP) and lithium (like OPTIMA's ORANGETOP). Battery lifespan between those three tends to also run from shortest to longest between flooded, AGM and lithium. However, how a marine battery is used and maintained can have a tremendous impact on how long it lasts, especially for lead-acid batteries.
Proper Voltage Maintenance
The best thing you can do to maximize battery performance and lifespan, is to properly maintain voltage in your batteries whenever possible. For lead-acid batteries, that means keeping them charged and maintained to at least 12.6V (~13.0-13.2V for BLUETOP OPTIMAs, except the 34M, which is fully charged at ~12.6-12.8V). Whenever any lead-acid battery is discharged below 12.4 volts and is left sitting in that state, sulfation will form in the plates, which diminishes capacity and lifespan.
Lithium batteries tend to have fewer issues with proper voltage maintenance, but it's still good practice to fully recharge your batteries as soon as you come off the water, to ensure they are ready to go the next time you are. You should also make sure the charging system on your boat (or stand-alone battery charger) is compatible with lithium batteries.
Cycle Life vs Battery Lifespan
The more deeply/faster you discharge a lead-acid battery, the fewer cycles you will get out of it. AGM can generally outperform flooded batteries in this regard, but there's no escaping Peukert's Law. What does that mean for your boat? We typically recommend getting the largest battery you can physically fit in the available space. To give you an example, we'll use an onboard refrigerator that consumes about 40AH/day. The smallest D34M BLUETOP will see about 73% of the rated capacity used, while the larger D27M will be at 61% and the D31M will be at 53% (the 34M is great for engine starting, but not designed or warrantied for deep-cycle use).
Even if the boat is started and run from one fishing spot to another and the batteries receive some charging during those runs, you can see how significant the different is between the different sizes. The smaller the battery, the more deeply and more often it will be cycled.
Move to a lithium battery, like OPTIMA's Q31M-DC150 ORANGETOP, which is a 150AH battery and the same refrigerator will only use about 27% of the rated capacity and the lithium battery will offer far more cycle life, regardless of the depth of discharge, when compared to the AGM battery. It's not a cheap upgrade, but if you plan to cycle your marine batteries deeply and frequently, it more than pays for itself over the lifespan of the battery.
Different Uses/Different Lifespans
Once again, we want to call out that not every marine battery sees the same use. A basic Ski Nautique that gets started once and runs every morning on a private lake in Florida may have very little demand on the battery once the engine is started. The boat makes a dozen or so runs on a slalom course over an hour or so and that's it for the day. A well-maintained lead-acid battery in that type of scenario could see 10-15 years of use. We've heard stories of some BLUETOPs lasting even longer in very basic marine applications. The batteries aren't cycled often or deeply and they are well maintained in between use.
On the other hand, a wakeboat that beaches on a sandbar and blasts a stereo all day long once a month could be far more demanding on the battery, especially if it's a short run to the sandbar, so the boat's charging system can't maintain proper voltage in the battery and the battery voltage isn't maintained in between use.
Cycle Life vs Calendar Lifespan
We've also heard of lithium brands touting up to 15,000 cycles for their products. With 365 days in a year, simple math suggests 15,000 cycles would take more than 41 years. Will you own your boat (or that battery) for that long? Even if you do own it, will a lithium battery last that long? How old is your cell phone? What's the longest lifespan you've ever had from a cell phone?
Chemical aging occurs even when a battery sits. Quality lithium packs can generally deliver 10-15 calendar years of useful life under normal conditions. Some premium packs may see even longer lifespan in moderate climates with good care. However, heat accelerates calendar aging and many lithium battery users will hit the calendar-life limit on their battery long before they approach an extreme cycle count like 15,000 cycles.
What Battery Chemistry is Right for You?
While we see many lithium brands only tout the benefits of lithium battery technology, we know that's not always the right fit for every boater. If you have significant electrical demands and cycle your battery (or batteries) often, like a tournament angler or a liveaboard boater, lithium batteries do make a lot of sense. If you are a recreational boater, who may only hit the water 10-12 times per year, lithium batteries might be overkill for your needs. If you bought a fishing boat for $700 and are just looking to get out on the water, an AGM battery may not fit your budget or needs. Choose the battery that's right for your needs, make sure you maintain voltage whenever possible and it will serve you well.
Some battery brands may offer warranties of ten years or more, suggesting their batteries will last that long. However, the reality in many of those warranties, is that the warranty becomes pro-rated within the first few years, so consumers end up paying for a warranty replacement, often at or above the brand's own cost. OPTIMA's warranty terms have no pro-ration, so when you buy a battery from us, if it needs replacement under warranty, the replacement is free.
Generally speaking, there are three types of marine battery chemistries commonly in use today- flooded lead-acid, AGM lead-acid (like OPTIMA's BLUETOP) and lithium (like OPTIMA's ORANGETOP). Battery lifespan between those three tends to also run from shortest to longest between flooded, AGM and lithium. However, how a marine battery is used and maintained can have a tremendous impact on how long it lasts, especially for lead-acid batteries.
Proper Voltage Maintenance
The best thing you can do to maximize battery performance and lifespan, is to properly maintain voltage in your batteries whenever possible. For lead-acid batteries, that means keeping them charged and maintained to at least 12.6V (~13.0-13.2V for BLUETOP OPTIMAs, except the 34M, which is fully charged at ~12.6-12.8V). Whenever any lead-acid battery is discharged below 12.4 volts and is left sitting in that state, sulfation will form in the plates, which diminishes capacity and lifespan.
Lithium batteries tend to have fewer issues with proper voltage maintenance, but it's still good practice to fully recharge your batteries as soon as you come off the water, to ensure they are ready to go the next time you are. You should also make sure the charging system on your boat (or stand-alone battery charger) is compatible with lithium batteries.
Cycle Life vs Battery Lifespan
The more deeply/faster you discharge a lead-acid battery, the fewer cycles you will get out of it. AGM can generally outperform flooded batteries in this regard, but there's no escaping Peukert's Law. What does that mean for your boat? We typically recommend getting the largest battery you can physically fit in the available space. To give you an example, we'll use an onboard refrigerator that consumes about 40AH/day. The smallest D34M BLUETOP will see about 73% of the rated capacity used, while the larger D27M will be at 61% and the D31M will be at 53% (the 34M is great for engine starting, but not designed or warrantied for deep-cycle use).
Even if the boat is started and run from one fishing spot to another and the batteries receive some charging during those runs, you can see how significant the different is between the different sizes. The smaller the battery, the more deeply and more often it will be cycled.
Move to a lithium battery, like OPTIMA's Q31M-DC150 ORANGETOP, which is a 150AH battery and the same refrigerator will only use about 27% of the rated capacity and the lithium battery will offer far more cycle life, regardless of the depth of discharge, when compared to the AGM battery. It's not a cheap upgrade, but if you plan to cycle your marine batteries deeply and frequently, it more than pays for itself over the lifespan of the battery.
Different Uses/Different Lifespans
Once again, we want to call out that not every marine battery sees the same use. A basic Ski Nautique that gets started once and runs every morning on a private lake in Florida may have very little demand on the battery once the engine is started. The boat makes a dozen or so runs on a slalom course over an hour or so and that's it for the day. A well-maintained lead-acid battery in that type of scenario could see 10-15 years of use. We've heard stories of some BLUETOPs lasting even longer in very basic marine applications. The batteries aren't cycled often or deeply and they are well maintained in between use.
On the other hand, a wakeboat that beaches on a sandbar and blasts a stereo all day long once a month could be far more demanding on the battery, especially if it's a short run to the sandbar, so the boat's charging system can't maintain proper voltage in the battery and the battery voltage isn't maintained in between use.
Cycle Life vs Calendar Lifespan
We've also heard of lithium brands touting up to 15,000 cycles for their products. With 365 days in a year, simple math suggests 15,000 cycles would take more than 41 years. Will you own your boat (or that battery) for that long? Even if you do own it, will a lithium battery last that long? How old is your cell phone? What's the longest lifespan you've ever had from a cell phone?
Chemical aging occurs even when a battery sits. Quality lithium packs can generally deliver 10-15 calendar years of useful life under normal conditions. Some premium packs may see even longer lifespan in moderate climates with good care. However, heat accelerates calendar aging and many lithium battery users will hit the calendar-life limit on their battery long before they approach an extreme cycle count like 15,000 cycles.
What Battery Chemistry is Right for You?
While we see many lithium brands only tout the benefits of lithium battery technology, we know that's not always the right fit for every boater. If you have significant electrical demands and cycle your battery (or batteries) often, like a tournament angler or a liveaboard boater, lithium batteries do make a lot of sense. If you are a recreational boater, who may only hit the water 10-12 times per year, lithium batteries might be overkill for your needs. If you bought a fishing boat for $700 and are just looking to get out on the water, an AGM battery may not fit your budget or needs. Choose the battery that's right for your needs, make sure you maintain voltage whenever possible and it will serve you well.
