Marine Battery Buying Guide
Marine
- Sponsor
- OPTIMA Batteries
- Location
- Glendale, WI
Why the Right Marine Battery Matters
Not all boat owners have the same needs or the same budget. Will their batteries be used just for starting or will they also be cycled as a house battery or trolling motor battery? Is this a purchase just to get the boat or jet ski out on the water (or to the next owner) or is this a long-term investment in performance? We know we can't cover every possible scenario, but we hope this overview will give you a good idea of which battery type will be the best for your boat or jet ski.
We know OPTIMA may not be in the cards for every boat owner too, so we'll try to give general information that can help guide you, regardless of the brand you choose. While OPTIMA is both a battery manufacturer and a battery brand, many of the batteries being sold today are being sold by brands with no battery manufacturing background or experience. We've watched a surprising number of these brands come and go, seemingly with the change of seasons. We don't want to see you get stuck with bad batteries from one of those vanishing brands. For deeper reading on the subject, this blog explains how you can identify a battery brand you can trust.
Types of Marine Batteries
Most boat owners can now choose between three widely available battery types, from least expensive to most expensive- flooded lead-acid, AGM lead-acid or lithium (hopefully, lithium iron phosphate). Along with significant differences in price, these batteries also offer significant differences in performance. While flooded lead-acid batteries are the least expensive option to get you on the water, they also typically offer the shortest lifespan. If you are a boater on a tight budget or getting ready to sell a boat that needs batteries replaced, flooded lead-acid batteries may be your best option and they are widely available at popular big box retailers, boat dealers and auto parts stores.
AGM batteries, like OPTIMA's BLUETOP batteries, are a significant step up from flooded lead-acid batteries in terms of price, but they can also offer up to three times the lifespan of a flooded lead-acid battery. If you plan on hanging onto your boat for a while, these are a very good choice that will pay for themselves over the life of the battery. Lithium batteries, like OPTIMA's ORANGETOP batteries offer the best performance and cycle life of the three types, but typically at the highest initial price point. Lithium batteries are a smart choice for professionals who spend a lot of time on the water. That could include tournament anglers, but it could include fishing guides or those who live aboard their boats and cycle their batteries on a daily basis.
In addition to the different chemistries, there are also marine batteries designed only for engine starting, like OPTIMA's 34M BLUETOP, batteries designed only for deep-cycle use, like OPTIMA's Q31M-DC150 ORANGETOP and batteries designed for both starting and deep-cycle use, like OPTIMA's D34M, D27M and D31M BLUETOPs and OPTIMA's Q31M-DP120 ORANGETOP. Many lithium batteries are only designed for deep-cycle use, but if you are looking for a lithium battery designed for engine starting, make sure it meets the requirements of your engine manufacturer (OPTIMA's Q31M-DP120 meets or exceeds Mercury's 2022 specifications for lithium-ion engine starting batteries).
Key Factors to Consider
The first thing we think you need to take into consideration when shopping for a marine battery, is that the battery is capable of operating in a marine environment, which may involve the battery getting wet. One of the most common failure modes we've heard about from tournament anglers is water intrusion into the case of the battery of their lithium batteries. There are also some battery brands that either offer no warranty coverage for marine applications or will void your warranty if the battery gets wet.
All OPTIMA ORANGETOP batteries for marine use, including batteries for jet skis and other personal watercraft are IP67-rated against water intrusion, which means they can be submerged up to one meter for 30 minutes without issue. Some battery brands may offer lesser IP ratings, but experienced boaters can give you all kinds of scenarios where they were glad their batteries could be submerged- they forgot to put in their drain plug, forgot to remove the drain plug, stuffing the bow into a heavy wave, getting caught in a heavy storm, etc...
Once you've determined the batteries you are considering can handle a marine environment, you'll probably look at specifications for cranking power and/or capacity. If you need a cranking battery, you should make sure the batteries you are considering meet or exceed the requirements of your engine, but there's no need to overbuy in this regard. Capacity, which could be listed in AH or minutes of reserve capacity or both, gives you an idea of how big your energy storage capacity is in your battery. If this is a strong consideration, we typically recommend buying the most AH you can fit into the space available, because the more deeply you cycle a lead-acid battery, the fewer cycles you will get out of it.
Certain applications, like offshore powerboats and personal watercraft may benefit from batteries that are more vibrations resistant, while that may not even be a consideration for a pontoon boat owner on a smaller inland lake. Weight may be an important consideration for some anglers, looking to equip a flats boat or kayak. Lithium batteries tend to offer significant weight savings over lead-acid batteries, but make sure you take into consideration how you are using the battery in such an application. Our QUAD30 ORANGETOP only weighs 7.1 pounds and offers lots of cranking power in powersports applications, but it only has 15AH of capacity. On the other hand, our Q31M-DP120 ORANGETOP is just over 43 pounds and significantly larger from a physical standpoint but also has 120AH of capacity.
Some flooded batteries, especially deep-cycle batteries designed for house use, may require periodic maintenance in the form of adding distilled water, while AGM and lithium batteries are sealed and require no such maintenance. All marine batteries are well-served with proper voltage maintenance, which is why many boats come with onboard chargers.
Sizing and Compatibility
The Battery Council International (BCI) designates specific battery sizes and the most common are Group 27, 31 and 34 of which OPTIMA offers options in all three. Unfortunately, the number designations often do no correlate with the size of the battery. Between those three sizes, the 34 is the smallest, the 31 is the largest and the 27 is in between the two. Many watercraft will have a designated area for a battery or batteries, some even requiring a specific size in a specific space. It's important to know what your boat or personal watercraft can accommodate in terms of physical size, before you make a purchase. A great place to start is by examining your current battery and understanding if you were to go with a larger size if there is enough space available to accommodate the battery.
While it is very common for multiple 12-volt batteries to be wired together for a 24 or 36-volt trolling motor battery, the same may be true for banks of house batteries on larger boats. Some of these house banks may use 6-volt or 8-volt batteries. While OPTIMA offers a 6-volt battery, it is designed & warrantied only for engine starting, not deep-cycle or house battery use. A larger boat with a 48-volt system may wire up six 8-volt batteries or eight 6-volt batteries to get to the voltage level they need. In those applications, we recommend sticking with the battery voltage recommended by the watercraft manufacturer.
We also recommend that anytime you are running more than one battery in the same application, whether they are wired in series or parallel, they should be identical in age, size and type. If one battery goes bad, all batteries should be replaced. You may be able to use the two other good 12-volt batteries in a 36-volt trolling motor application somewhere else, but you should definitely make sure all three are identical in those three ways.
Best Practices for Long Battery Life
It's not unusual for boats to have anywhere from two to five batteries. Even if you only bought two flooded batteries for a skiff with a trolling motor, you're making a significant investment and will want to maximize battery performance and lifespan. The best way to do that is with proper voltage maintenance, both in season and out of season with a quality battery maintenance device. Make a point of charging your batteries as soon as you come off the water, instead of leaving them in a partially discharged state for weeks or months and trying to charge your batteries the day before you head back out and hoping things will work out.
In terms of storage temperatures, batteries store best in cool (but not frigidly cold), dry locations. If you don't have electrical access where you store your boat or jet ski, the next best practice is to fully charge your battery with a battery charger and completely disconnect it when putting your watercraft into storage. When you bring it back out, fully recharge the battery again with a battery charger, before you head for the water.
Not all boat owners have the same needs or the same budget. Will their batteries be used just for starting or will they also be cycled as a house battery or trolling motor battery? Is this a purchase just to get the boat or jet ski out on the water (or to the next owner) or is this a long-term investment in performance? We know we can't cover every possible scenario, but we hope this overview will give you a good idea of which battery type will be the best for your boat or jet ski.
We know OPTIMA may not be in the cards for every boat owner too, so we'll try to give general information that can help guide you, regardless of the brand you choose. While OPTIMA is both a battery manufacturer and a battery brand, many of the batteries being sold today are being sold by brands with no battery manufacturing background or experience. We've watched a surprising number of these brands come and go, seemingly with the change of seasons. We don't want to see you get stuck with bad batteries from one of those vanishing brands. For deeper reading on the subject, this blog explains how you can identify a battery brand you can trust.
Types of Marine Batteries
Most boat owners can now choose between three widely available battery types, from least expensive to most expensive- flooded lead-acid, AGM lead-acid or lithium (hopefully, lithium iron phosphate). Along with significant differences in price, these batteries also offer significant differences in performance. While flooded lead-acid batteries are the least expensive option to get you on the water, they also typically offer the shortest lifespan. If you are a boater on a tight budget or getting ready to sell a boat that needs batteries replaced, flooded lead-acid batteries may be your best option and they are widely available at popular big box retailers, boat dealers and auto parts stores.
AGM batteries, like OPTIMA's BLUETOP batteries, are a significant step up from flooded lead-acid batteries in terms of price, but they can also offer up to three times the lifespan of a flooded lead-acid battery. If you plan on hanging onto your boat for a while, these are a very good choice that will pay for themselves over the life of the battery. Lithium batteries, like OPTIMA's ORANGETOP batteries offer the best performance and cycle life of the three types, but typically at the highest initial price point. Lithium batteries are a smart choice for professionals who spend a lot of time on the water. That could include tournament anglers, but it could include fishing guides or those who live aboard their boats and cycle their batteries on a daily basis.
In addition to the different chemistries, there are also marine batteries designed only for engine starting, like OPTIMA's 34M BLUETOP, batteries designed only for deep-cycle use, like OPTIMA's Q31M-DC150 ORANGETOP and batteries designed for both starting and deep-cycle use, like OPTIMA's D34M, D27M and D31M BLUETOPs and OPTIMA's Q31M-DP120 ORANGETOP. Many lithium batteries are only designed for deep-cycle use, but if you are looking for a lithium battery designed for engine starting, make sure it meets the requirements of your engine manufacturer (OPTIMA's Q31M-DP120 meets or exceeds Mercury's 2022 specifications for lithium-ion engine starting batteries).
Key Factors to Consider
The first thing we think you need to take into consideration when shopping for a marine battery, is that the battery is capable of operating in a marine environment, which may involve the battery getting wet. One of the most common failure modes we've heard about from tournament anglers is water intrusion into the case of the battery of their lithium batteries. There are also some battery brands that either offer no warranty coverage for marine applications or will void your warranty if the battery gets wet.
All OPTIMA ORANGETOP batteries for marine use, including batteries for jet skis and other personal watercraft are IP67-rated against water intrusion, which means they can be submerged up to one meter for 30 minutes without issue. Some battery brands may offer lesser IP ratings, but experienced boaters can give you all kinds of scenarios where they were glad their batteries could be submerged- they forgot to put in their drain plug, forgot to remove the drain plug, stuffing the bow into a heavy wave, getting caught in a heavy storm, etc...
Once you've determined the batteries you are considering can handle a marine environment, you'll probably look at specifications for cranking power and/or capacity. If you need a cranking battery, you should make sure the batteries you are considering meet or exceed the requirements of your engine, but there's no need to overbuy in this regard. Capacity, which could be listed in AH or minutes of reserve capacity or both, gives you an idea of how big your energy storage capacity is in your battery. If this is a strong consideration, we typically recommend buying the most AH you can fit into the space available, because the more deeply you cycle a lead-acid battery, the fewer cycles you will get out of it.
Certain applications, like offshore powerboats and personal watercraft may benefit from batteries that are more vibrations resistant, while that may not even be a consideration for a pontoon boat owner on a smaller inland lake. Weight may be an important consideration for some anglers, looking to equip a flats boat or kayak. Lithium batteries tend to offer significant weight savings over lead-acid batteries, but make sure you take into consideration how you are using the battery in such an application. Our QUAD30 ORANGETOP only weighs 7.1 pounds and offers lots of cranking power in powersports applications, but it only has 15AH of capacity. On the other hand, our Q31M-DP120 ORANGETOP is just over 43 pounds and significantly larger from a physical standpoint but also has 120AH of capacity.
Some flooded batteries, especially deep-cycle batteries designed for house use, may require periodic maintenance in the form of adding distilled water, while AGM and lithium batteries are sealed and require no such maintenance. All marine batteries are well-served with proper voltage maintenance, which is why many boats come with onboard chargers.
Sizing and Compatibility
The Battery Council International (BCI) designates specific battery sizes and the most common are Group 27, 31 and 34 of which OPTIMA offers options in all three. Unfortunately, the number designations often do no correlate with the size of the battery. Between those three sizes, the 34 is the smallest, the 31 is the largest and the 27 is in between the two. Many watercraft will have a designated area for a battery or batteries, some even requiring a specific size in a specific space. It's important to know what your boat or personal watercraft can accommodate in terms of physical size, before you make a purchase. A great place to start is by examining your current battery and understanding if you were to go with a larger size if there is enough space available to accommodate the battery.
While it is very common for multiple 12-volt batteries to be wired together for a 24 or 36-volt trolling motor battery, the same may be true for banks of house batteries on larger boats. Some of these house banks may use 6-volt or 8-volt batteries. While OPTIMA offers a 6-volt battery, it is designed & warrantied only for engine starting, not deep-cycle or house battery use. A larger boat with a 48-volt system may wire up six 8-volt batteries or eight 6-volt batteries to get to the voltage level they need. In those applications, we recommend sticking with the battery voltage recommended by the watercraft manufacturer.
We also recommend that anytime you are running more than one battery in the same application, whether they are wired in series or parallel, they should be identical in age, size and type. If one battery goes bad, all batteries should be replaced. You may be able to use the two other good 12-volt batteries in a 36-volt trolling motor application somewhere else, but you should definitely make sure all three are identical in those three ways.
Best Practices for Long Battery Life
It's not unusual for boats to have anywhere from two to five batteries. Even if you only bought two flooded batteries for a skiff with a trolling motor, you're making a significant investment and will want to maximize battery performance and lifespan. The best way to do that is with proper voltage maintenance, both in season and out of season with a quality battery maintenance device. Make a point of charging your batteries as soon as you come off the water, instead of leaving them in a partially discharged state for weeks or months and trying to charge your batteries the day before you head back out and hoping things will work out.
In terms of storage temperatures, batteries store best in cool (but not frigidly cold), dry locations. If you don't have electrical access where you store your boat or jet ski, the next best practice is to fully charge your battery with a battery charger and completely disconnect it when putting your watercraft into storage. When you bring it back out, fully recharge the battery again with a battery charger, before you head for the water.