Surprisingly, the lead acid battery that we use today is pretty much the same as our great-great grandparent’s lead battery. So once you understand the basics, it will be much easier to sift through the information and reduce sensory overload when looking through all of the marine battery reviews. Most batteries are constructed in much the same way with a few modern twists in construction and chemicals.
If you printed all of the information available for boat batteries and brands, you would be buried in paper. There are several things to understand about marine batteries before going any further in your search for the best marine battery for your needs. Some things are basic to any good battery.
In this article, we will provide a complete guide you can choose the best battery for your boat. But first let’s consider some of the best marine batteries on the market.
Top 5 Best Marine Battery
Optima 8016-103-FFP D34M BlueTop
- Dual purpose
- Starting and deep cycle capability
- Three times more recharge
- Stainless steel posts
This is a dual purpose marine battery with both starting and deep cycle capability. This Optima BlueTop battery can take three times more recharge than other lead acid batteries. This marine battery is totally spill proof and is compatible with any mounting position. It has unique stainless steel posts that make the battery fifteen times more resistant to heavy vibrations and have more durability. The reserve capacity of this battery is 120 minutes, when used constantly. The weight of this optima BlueTop battery is 47 pounds and used mostly in boats and trolling motors.
- Heavy duty deep cycle
- Vibrations and shock proof
- Unique plate structure
This is a heavy duty deep cycle marine AGM battery, weighing 60 pounds with estimated life span of 8-10 years. The plates of the Vmaxtanks MR107 battery is designed with unique technology and the plates have very different chemical and physical structures, which make the battery more reliable and strong. The absorbed glass mats are placed in a unique manner that makes the battery resistant to heavy vibrations and shocks. The heavy duty lead and tin alloys give the battery high performance capacity and longer life cycle. The Vmaxtanks MR107 battery is sealed in a unique tank that makes it 100% maintenance free. The Vmaxtanks MR107 battery is a very good choice for boats and trolling motors.
Odyssey 34M- PC1500ST
- Dual purpose
- Vibration and shock resistant
- Works in extreme temperature
- Maintenance free
This is a dual purpose AGM marine battery. It has both tremendous starting power and extreme deep cycling capabilities and at 80% discharge and it can take up to 400 deep cycles. The Odyssey 34M-PC1500ST battery is designed in a specialized way, which makes it resistant to high vibrations and shocks. This battery can tolerate most extreme temperatures, least at -40°C and highest at 80°C. The CCA of this battery is 880. The Odyssey 34M- PC1500ST battery is totally a zero maintenance battery with no need of adding water. It weighs 50 pounds and the cost of this battery is a little expensive, but the amazing features worth it.
UB121000 Universal batter
- AGM technology
- 100Ah power
- Starting and deep cycle
- Flexible in any position mounting
This is an absorbed glass mat sealed lead acid 12 volt battery and the AGM technology makes this battery’s performance superior. The valve regulated design makes the UB121000 Universal battery spill proof and it can be mounted in position, making the battery work flexibly. The power of this battery is 100Ah and it can last for 20 hours. The UB121000 Universal battery can be used as both starting as well as deep cycle battery, for running many units like vehicles, trolling motors, golf carts, emergency lighting and many more. This battery weighs 60 pounds and cheap enough for regular use.
- Megacycle with 200 minute RC
- Dual terminal
- 925 CCA at 0°F
- High vibration proof
This is megacycle maintenance free absorbed glass mat battery, with 40% more acceptance of charge than other 31 series lead flooded batteries. The Exide XMC-31 battery has a dual terminal design and it is engineered in a way that it can bear heavy vibrations as well as extreme deep cycles. The separator of the absorbed glass mat in this battery is designed with recombination technology, due to which cell dry-out never occurs. The CCA of the Exide XMC-31 battery is 925 at 0°F and 1110 at 32°F. The reserve capacity of this battery is 200 minutes and weighs 78 pounds.
The battery is composed of five major parts: the resilient plastic container, positive and negative internal lead plates, plate separators made of porous synthetic material and electrolyte (a solution of sulfuric acid and water). This mix is better known as battery acid with modern applications adding some other ingredients. Finally, lead terminals are the connection point between the battery and whatever it powers.
- The first step in the process of constructing a battery is the resilient polypropylene container. The container is divided into six sections also referred to as cells, which are shaped similarly to an ice cube tray.
- Next are the positive and negative internal grids (plates). These grids are made from lead or an alloy of lead and other metals used for positive and negative plates that will conduct the charge. The construction of the grids varies from manufacturer to manufacturer and battery to battery.
- After the plates, a paste mixture is applied to the grids. The paste mixture of lead oxide, sulfuric acid, and water is applied to the grids. A mixture called electrolyte expander, a material made of powered sulfates, is added to the paste to produce negative plates. The composition of the paste can be proprietary and also varies with manufacturer and battery use.
- Separators are used to prevent short circuits. They are thin sheets of porous insulating material used as spacers between the positive and negative plates. Fine pores allow electrical current to flow between the plates without shorting and burning. Different manufacturers are beginning to use different materials for the separators as well.
When pairing a positive and negative plate with the separator, the combination is called an element. There is only one element per cell. The cells are connected with a metal that conducts electricity. The lead terminals or posts are welded on. The construction materials used to manufacture the posts have changed over the years as well. Many of the materials that are used have been designed for the purpose of reducing corrosion, for example, many manufacturers offer stainless steel terminals. The last two steps are to charge the battery and adhere labels.
The electrolyte is lead and lead oxide, which traditionally was a 35% sulfuric acid and 65% water solution. The electrolyte causes a chemical reaction that produces electrons. Over time pulling a load, the sulfur rests on the battery plates reducing the amount of sulfuric acid in the electrolyte. When the electrolyte loses sulfuric acid, electrons stop being made; so, there is less power created. When the battery is charged, the sulfur returns to the electrolyte, returning power to the battery. Technological advances have provided different mixtures that reduce the amount of sulfuric acid that adheres to the plate thus extending the reserve time (the amount of time the battery can take a load without being charged).
The Elements of a Good Marine Battery
There are three major chemistries to consider when searching for a battery, flooded batteries, gel batteries, and AGM batteries, as well as one newcomer whose technology was developed to power newer amenities created from newer technology, the lithium battery, which is making an appearance on more and more boats.
- Flooded batteries, also called wet batteries, use a reservoir of liquid sulfuric acid to create a pathway between plates to produce the electrolytes. The electrolytes produce hydrogen and oxygen while the battery is being charged which, of course, requires a vented battery box. These batteries require periodic refilling with distilled water in addition to other maintenance needs.
- Gel Batteries are named from the combination of sulfuric acid, fumed silica, pure water, and phosphoric acid making up the electrolyte. The gel is viscous and prevents leaks. These are recombinant (resulting from new combinations) from the small amount of gasses that combine to make water and prevent drying out due to charging. The charging system must be carefully regulated to prevent high voltage overcharging. No vents mean no gasses escaping, which means less maintenance.
- AGM Batteries or Absorbed Glass Mat batteries feature glass mat separators saturated with acid between the battery’s positive and negative plates. While charging, pressure valves allow oxygen produced on the positive plate to migrate to the negative plate and recombine with hydrogen and produce water. These batteries have a lower internal resistance that allows for greater starting power and charge reception. Again, with no gasses escaping, less maintenance is needed.
- Lithium Technology batteries are lighter than the lead-acid counterparts. These batteries can be discharged 800 times to 100% and recharge in about an hour. They work beautifully for electric boats and other high-performance applications.
The costs involved with marine batteries varies by type, brand and application. An economically priced battery used for the wrong purpose and/or not properly maintained, will create more expense in the long run.
- The flooded battery is the least expensive of all the battery options available. However, they do require more maintenance than other batteries. If you want more fun than maintenance, it would be wise to invest in a more advanced technology.
- For many owners, the Gel technology has proven to be overrated. Others are very pleased. Priced between the flooded battery and the AGM battery, there are reports that the concerns about vibration and the lower cycle rates, and the environmental concerns surrounding the silica used to gel the electrolyte make this a less appealing alternative. It is safer with less maintenance than the flooded battery, so it still may be worth the cost.
- The AGM battery seems to be at the top of the list for traditional technology. The glass mat resists vibration and makes the battery more spill proof than the flooded and gel chemistries. It is longer lasting than both. There are significantly higher upfront costs that do vary between brands. Many reviews of the AGM battery do warn the buyer than ‘you get what you pay for’. Finding a truly higher quality battery seems to be worth the cost, but only when properly maintained.
- The most costly battery to purchase is the lithium battery. The upfront costs for a quality battery can start at three times the cost of the flooded battery. The costs for batteries really does depend on the brand and the habits of the user versus the manufacturer’s instruction
Considering brand, chemistry, warranty, and user habits make calculating lifetime costs very difficult. If you pay only $50.00 for a battery that only lasts for one season compared to a $200.00 battery that lasts 6-8 years you may well want to put out the $200.00. That only figure accounts for a small boat that only requires one 12 volt battery. The larger the boat and the more accessories requiring power will certainly increase costs. Looking at some different chemistries and technologies there are some numbers that can be used for guidance.
- Lithium batteries are the newest technology, and they are still advancing and of course prices vary over time. The following is a breakdown of costs per amp for a medium sized 12-volt marine battery.
- Traditional Marine: $21.25 per Ah
- Packagers: $10-15 per Ah
- DIY: $3.50-5 per Ah
The packager bundle includes a Battery Management System (BMS) while the DIY is individual cells purchased with the BMS purchased separately.
- Traditional chemistry battery costs are quite different.
- AGM $3.00-3.50 per Ah
- Lead Acid $0.90-1.33 per Ah
These are certainly conservative estimates, but it is always ‘better to be safe than sorry’.
Applications for Use
There are three major applications to consider when choosing a battery: Starting the motor, maintaining a charge when out on the water away from the shore, and the feasibility of a dual-purpose solution.
- The Starting batteries crank the starter of the boat’s engine; they are good for a short burst of 75-400 amperes for 5-15 seconds when the alternator takes over. Like other batteries, they are also constructed with the alternating layers of negative and positive plates, but the plates are thinner and more numerous. The design of the plates allows for more surface area enabling the battery to generate high amperage bursts of current. These batteries are fragile, and they are not as effective in hostile climates. The harsh, hostile climate and deep charges will reduce their operation lifespan. These are sprinters, not long lasting batteries, and are not able to withstand the enduring charge needed for electronic equipment or a trolling motor.
- The Deep Cycle battery works well for applications where there is no shore charge available, or there is no solar charger available for recharging the battery. The plates in the deep cycle battery are thicker with more antimony and, therefore, are better able to maintain a charge. On average they deplete 50-70% of capacity when used overnight. Of course, this depends on what the battery is powering. The more amenities, the faster the capacity is depleted. Modern technology has created the need for elements of the deep cycle battery contributing to longer reserve time and lifespans.
- There is a dual-purpose battery, and it is good for certain applications. However, it is not always as effective as a starter battery for starting or a deep cycle battery for the longer use of the remaining electric system. In many cases, using the battery designed for the specific purpose is best. If necessary and feasible, the dual-purpose is a good compromise. These batteries can withstand a deep charge better than a starting battery. There are some specific instances where a dual-purpose battery works best.
- Runabouts or other small powerboats small enough to use a single battery for both.
- Sailboats with two identical batteries used interchangeably for starting and load bearing.
- Boats with only one battery bank for both operations. The dual-purpose will last long with more reliable service than the starting and deep cycle separately. It will prove worth the extra $20.00 paid for the dual-purpose battery.
When buying a battery, look for the greatest reserve capacity or amp hour rating. To determine the battery needs of your boat, it is important to calculate the AMP hour capacity you need. This is not as difficult as it sounds. Add up the 12-volt accessories you have and multiply that by 20. It is only an approximation but will still give a good idea of your boat’s requirement. It is also a good idea to find a battery that provides at 20% over that number.
To find the proper starting battery, you must know the size of the engine that will determine the MCA (Marine Cranking Amp) needs. Of course, the higher the horsepower of the engine, the higher the MCA rating you will need to buy.
It is important to consider the physical size, cable hookup, and terminal type needed. In a harsh climate where the boat will be stored for a length of time, a GEL or an AGM may be the better options. The broader the warranty, the better the battery.
The current average lifespan of a battery is 6 months to 48 months, and few make it to the 48th month. The life of the marine battery can be extended by hooking it to a solar charger when not using it for a period.
If you choose one chemical type battery for a starting battery, the same chemical type must be used for deep cycle battery in the same boat. For example, if an AGM battery is used as a starter battery an AGM must be used for the deep cycle battery as well.
Care and Maintenance of the Marine Battery
The time to look at the care and maintenance of batteries is before you buy the battery. You could purchase the best marine battery money can buy, but if it is not cared for properly the money is wasted. Some batteries may need extra attention and others less, but some maintenance is needed on all types and manufacturers.
- Clean the top of the battery. Remove dirt and corrosions on the terminals with a wire brush post cleaner to remove the corrosion. This simple task helps extend the lifespan and the flow of electricity. Many manufacturers suggest that a thin layer of an oil-based lubricant be used on the terminals. Some DIYers suggest Vaseline.
- Charging is especially important for sealed maintenance free batteries. The manufacturers have information normally on the battery itself for charging lengths and when the battery must be charged, for example, when the boat has not been used for a period.
- Routine Checks for bulges or cracks on the outside of the battery are very important. There may be a problem with the boat’s alternator or the charging system you are using. Verify the voltage to ensure it is correct.
- Seasonal storing requires a trickle charge. Do not store the battery without a charging device
- Check water levels in flooded deep cycle batteries to be sure there is enough water. It is very important to use distilled water.
It is also important to know when it is time to replace your battery. Watch for symptoms such as
- You had to jump-start your battery
- The battery struggles to turn the starter over
- Lighting and electronics dim or go out when starting
- The battery does not hold a charge
- Whenever the battery becomes submerged
- The battery frequently discharges between use
- And especially, if you bought a used boat.
Being stranded away from shore is not where anyone one wants to be on a beautiful day of boating. Remember if you don’t take care of your battery, your battery won’t take care of you!
Now that you know how to take care of the battery and when to replace the battery, we can look at some marine battery reviews.
ACDelco batteries are pressure tested to help avoid a leak, strength, and rigidity. Thermoplastic reinforced plates help increase protection against plate shooting for improved durability. Some ACDelco deep cycle models feature built-in ‘Green Eye’ hydrometers. Both positive and negative grids are lead/calcium alloy to maximize corrosion resistance that, in turn, increases the cycle life and reduces cycle life for consumption and battery durability.
Exide Edge batteries tout 775 cold cranking amps to its list of features. You can operate all onboard accessories with its 145 hours of reserve time. It boasts SureLife Graphite Technology to maximize energy capacity. The battery is sealed to ensure it is completely non-spillable.
Lifeline products are well known and trusted marine products. They are available nationwide and carry a good 5-year pro-rated warranty. Without specifying the individual technical traits, this battery line is manufactured by the same company that is an industry leader in aerospace battery lines and whose product has been proven through use by many branches of the US military.
Optima’s pricing is a little higher, but most reviews hold that the price is well worth the difference. It touts a 155-minute reserve, starting power in bad weather, and 15 times more resistance to vibration making it a durable product. The BlueTop battery is designed as a dual-purpose battery for a maintenance-free power source.
Power King Batteries have a reputation for reliability. They feature stainless steel terminals, hybrid grids with centerline lugs, high-density oxide and polyethylene envelope separators, and safety vent caps. Power King Batteries are also resistant to excessive vibrations that can lead to failure.
Rolls Batteries are respected for reliability in northeastern climate conditions. This outlasting service is enhanced by dual container construction promising the elimination of breakage due to rough handling and abuse. Repairs are simpler and less time-consuming allowing the boater to get back in the water.
Sonnenschein batteries enjoy international acclaim. The parent company is located in Germany, and the products are used on continents around the world. They have unique microfiber glass separators, have enough electrolytes to sustain the life of the battery and should not be opened. Careful attention should be paid to the voltage/temperature guidelines.
Superior Superflex batteries boast of a dual post design, maintenance free deep cycle battery. Its high-density premium oxide, high-performance separator and embedded glass mat combined with corrosion resistant terminals make this battery a good fit for all outdoor applications.
Trojan batteries are the pioneer batteries. Trojan started its journey in 1925 and continued to research and develops to continue providing an exceptional battery. Trojan touts proprietary formulas for separators and paste formulas for enhanced performance and durability.
US Battery products have Microrib Flexsil separators, Crystalock high-density paste to maximize runtime and battery life. The fiberglass backing ensures maximum life, a positive locking system called SeedCap venting, Rotocast High Torque defect free terminals and heavy duty internal connections all designed to outperform. US Battery is also one of the pioneering manufacturers making batteries since 1926.
Interstate Batteries carries a full range of marine batteries to choose from. Whether you need a starting motor or trolling motor, Interstate has a solution. The ECL Professional starts at 690 CCA, and 140 RC minutes. Unfortunately, there is only an 18-month replacement warranty. The Deep Cycle models provide from 100 RC to 390 RC minutes, but the replacement warranty period is very short. The top model is a beauty that promises dual duty is topping out at 1190 MCA and 190 RC minutes. One battery for all needs. Easing fears of using a dual purpose battery for both starting and trolling Interstate promises replacement for up to 36 months. The warranty alone is worth the additional charge.
Odyssey Marine Batteries are designed for powerful dual purpose use. There are only variations of dual purpose that promise starting, deep cycle power. The Odyssey has not lead alloy, but pure lead plates. The pure lead plates allow for more plates to fit in the casing, providing two times the surface area. It is capable of providing 2200 bursts for starting and up to 400 charge-discharge cycles. Odyssey provides a 24-month replacement warranty.
VMAX Batteries promises their VMAX Tank series are tough enough for military applications. Whether gas or electric, whether you need starting power or sustaining power for electronic equipment on board, there is a solution for your needs. The biggest and best VMAX boasts of 170Ah with a 360 RC minute reserve capabilities for the power boat application. The bottom technology battery boasts of 390 MCA and 75 RC minutes. There is a 12-month warranty against defect or workmanship.
Battery Tenders Lithium Batteries marine applications are designed for the unique needs of your Personal Water Craft. Their best battery promises 480 CCA, with a replacement range of 26-35 Ah. With proper use and maintenance, it boasts an 18-month shelf life and 2000 deep cycles at 80% Depth of Discharge can be mounted in any direction for ease of installation. The Battery Tender Charging Products are the state of the art chargers built with Deltran’s patented Battery Tender BTP Microprocessor Technology. The easy connect convenience automatically maintains all the batteries in your boat. It is so simple to use, just connect it, and it begins its work saving your hundreds of dollars in replacements. Trusted by dealers, collectors, and fleet owners; you can certainly trust the ‘Tender’ with yours.
After looking at all of the marine batteries, their applications, care, and marine battery reviews it is important to note that the best marine battery(ies) for you really depends on the boat, its size, the electronic devices it must power along with the other applications and your budget. Remember one of the best determiners for a good battery is the warranty offered by the manufacturer. Have a great boating season!