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10 Best Marine Battery Chargers – (Reviews & Buying Guide 2021)

A marine battery charger is one of the least expensive parts of your boat, and at the same time, one of the most significant things when it comes to keeping your battery in good condition and maximizing its performance. If you search the Internet for the best marine battery charger, you are bound to feel overwhelmed as you will see that there are thousands of products you can choose from.

A high-quality marine battery can last from four years to a decade or more, can be charged hundreds of times and yet can be damaged completely through just one time if you use the wrong kind of charger. Having a reliable charger is as vital as having well-working batteries.

However, finding the most suitable product may not be as easy as it looks. There are different types of chargers and various features to look for. Luckily for you, our buying guide has it all – helpful information, tips, and, of course, reviews on the best marine battery chargers.

Best Marine Battery Chargers Comparison Chart

NOCO Genius GEN3 Waterproof Smart On-Board Battery Charger

NOCO Genius GEN3 Waterproof Smart On-Board Battery Charger

  • Price: $$$$
  • Dimensions: 16 x 6 x 14″
  • Weight: 12 pounds
  • Amperage: 30 Amp
  • Pros: Charges 2 times faster / Waterproof
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Battery Tender Plus Battery Charger

Battery Tender Plus Battery Charger

  • Price: $
  • Dimensions: 11 x 4 x 11″
  • Weight: 2 pounds
  • Amperage: 1.25 Amp
  • Pros: Quickly connected harness / Fully automatic
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Minn Kota On-Board Digital Charger

Minn Kota On-Board Digital Charger

  • Price: $$ – $$$$$
  • Dimensions: 11-1/2″ Length , 7-1/2″ Width , 4″ Height
  • Weight: 11 pounds
  • Amperage: 5 / 10 Amp
  • Pros: Waterproof and shock-resistant / Comes with an AC Plug Holder
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Battery Tender 5-Bank

Battery Tender 5-Bank

  • Price: $$$$$
  • Dimensions: 18 x 9 x 12″
  • Weight: 13.1 pounds
  • Amperage: 4 Amp
  • Pros: Can be Used for 5 batteries at the same time / Fully automatic
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ProMariner ProSport Generation 3 Battery Charger

ProMariner ProSport Generation 3 Battery Charger

  • Price: $$$ – $$$$$
  • Dimensions: 7.2 x 2.8 x 9.9″
  • Weight: 4 pounds
  • Amperage: 12 Amp
  • Pros: Energy Saver Mode / Storage Recondition Mode
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Tecmate Optimate 6 Ampmatic Battery Saving Charger

Tecmate Optimate 6 Ampmatic Battery Saving Charger

  • Price: $$
  • Dimensions: 12.3 x 7 x 3.4″
  • Weight: 3 pounds
  • Amperage: 5 Amp
  • Pros: Battery save function / Waterproof and fully sealed
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BMK BLUEMICKEY Smart Battery Charger Portable Battery Maintainer

BMK BLUEMICKEY Smart Battery Charger Portable Battery Maintainer

  • Price: $$$
  • Dimensions: 9.5 x 4.6 x 2.9″
  • Weight: 1.76 pounds
  • Amperage: 5 Amp
  • Pros: 4 stages of automatic charging process / Multifunctional
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These are the top products you could possibly find on the market these days. Each has pros and cons, but we are sure that they will all make your boat’s performance excellent. Bear in mind that they are not arranged in any particular order, the choice is entirely yours.

1. NOCO Genius GEN3 Waterproof Smart On-Board Battery Charger

NOCO Genius GEN3 Waterproof Smart On-Board Battery ChargerThe NOCO Genius GEN3 can be used for boats, tractors and other equipment. Also, it has a fully sealed and waterproof design. This particular battery has an intelligent NOCO vosfx processor. With the help of this processor, you can monitor the power input, the attached battery, and the charger all the time. The Genius GEN3 can charge and maintain every type of lead-acid batteries from 25-230Ah.  It is safely designed, which means that the cell doesn’t generate sparks and the construction protects you from reverse battery hookup, open circuit, overheat short course.

The GEN3 is completely sealed and waterproof. It can hold against the most severe environments, and it is rated at IP68. Features advanced Rapid Charging Technology. Meaning that this unit can power up batteries twice faster than the ordinary battery chargers. It is lightweight, only 12 pounds, which will not cost you more money for the shipping and it is 11.2 x 6.3 inches big.

If the charger is in Bulk charge mode for a more extended period, the charger will automatically shut off. In the box, that comes with, you will receive a manual, the charger, user guide, and the unit’s registration card.


  • 100 percent completely sealed
  • Waterproof
  • Its safe design will protect you from unwanted reverse polarity, open-circuits, sparks, short-circuits and overheating
  • Charges 2 times faster than the standard battery chargers
  • If a low-voltage, lost capacity or sulfation are detected a high-voltage pulse will be applied to recover


  • The included screws are not self-tapping

2. Battery Tender Plus Battery Charger

Battery Tender Plus Battery ChargerThe Battery Tender Plus 021-0128 is a fully automatic, 1.25A battery charger. Its purpose is to charge a battery at its maximum and keep it at a proper storage voltage. It is charging very fast and efficient. It will charge your battery faster than any 3 amp charger. It is incredibly lightweight, only 2 pounds and it is 11 x 4 x 11 inches big. It comes in a package with Battery Tender ring terminals and alligator clips.

For safe use, the manufacturer has designed two lights, green and red. Indicating the state of the charger. Features reverse polarity protection for more extensive safety when using the charger. If you see a flashing red light, this means that there is a problem with the battery connection. The unit will automatically switch from full charging mode to float charging.

The Battery Tender Plus has a ten-year warranty. It is straightforward to install the unit, you don’t need a mechanic to help you with it. Keep in mind that the battery needs to have at least 3V before starting to charge.


  • Charger faster than any 3amp charger
  • Green and Red lights, indicating the state of your battery charger
  • A quickly connected harness is included in the package, for hard to reach places


  • This is better for smaller batteries; otherwise, it will take a lot of time to charge for example a car battery

3. Minn Kota On-Board Digital Charger

Minn Kota On-Board Digital ChargerFeaturing a LED Status Display, the Minn Kota charger will give you information about the charging process at any time. There are three lights: yellow, green and red. The yellow one indicates when it is charging, the green one will appear when the battery is fully charged, and the red one will display when there is a problem with the connection. It comes with an AC Plug Holder. This is for more extensive safety when using the charger. The plug will dry, accessible and safe to use.

This unit is suitable to be used on your boat. This is because the product is waterproof, shock-resistant and vibration-resistant. Features an ATC, which means an Automatic Temperature Compensation. With the help of the ATC, the charger will adjust according to the outside temperature to prevent damage to your battery.

A good tip is that you don’t need to worry if you haven’t used the charger in months. The charger will not drain the batteries when you decide to use it again.


  • Easy to use and install
  • Three indicating lights
  • Waterproof and shock-resistant


  • After two years it might stop working

4. Battery Tender 5-Bank

Battery Tender 5-BankA significant advantage of this battery charger is that it is capable of charging up to 5 6V batteries or 12-volt lithium batteries at the same time. Due to its advanced 4-step charging system, it can fully charge the batteries and maintain them, without overcharging. This unit is spark-free because of the installed microchip circuitry. This microchip will not activate at any circumstances an output voltage unless the clips are accurately linked to the battery.

With the help of the lights above each station on the charger, you can understand the state of your charger. You can also know when the battery is charging following the yellow line. Its dimensions are 18 x 9 x 12 inches. And weighs around 13.1 pounds.

Good advice will be to order extension cables. The one that comes with the charger is quite short which might make it difficult to use.


  • Charging and maintaining up to 5 batteries at the same time
  • Comes with a 3-year warranty
  • No chance of overcharging the cells because of the 4-step charging system
  • Lights indicating the state of the charger
  • It is fully automatic


  • Comes with a short length wires
  • Makes high pitched tone when it is plugged in

5. ProMariner ProSport Generation 3 Battery Charger

ProMariner ProSport Generation 3 Battery ChargerIt is nice knowing that your batteries are always fully charged and you are ready to go to your favorite place anytime. This charger is well made and weighs about 4 pounds. The unit is a two-bank charger, the first bank is for Cranking Battery and the second bank is for House Battery (known as Trolling Motor).

Pay attention that the one cord is specifically designed to hook up to the trolling cell and the other to the cranking one. It takes about 4 hours to charge both batteries had they been completely dead when you hooked up the charger. The most impressive thing that may be helpful for you is to know that if you have multiple batteries connected in series the battery charger will still charge both batteries together. For example, if you have 2 trolling motor batteries connected in series, this charger won’t let you down.

The lighting system on this charger is impressive, it shows you everything the charger is doing, including the status of your batteries


  • 2 Year Warranty
  • Energy Saver Mode
  • Storage Recondition Mode
  • Built-in Quality and Safety


  • Doesn’t come with any hardware to secure the charger
  • It may not charge the second battery at 100%

6. Tecmate Optimate 6 Ampmatic Battery Saving Charger

The Tecmate OptiMate 6 charger advanced fully automatic 12V battery charger. It is handy because it saves batteries. This a feature that the charger recognizes the difference between a discharged or sulfated battery. The way of protecting the cells is by starting the charging on a low volt of 0.5V, and after that, there is a two-step de-sulphation recovery.  That’s why the ampmatic current control with the cell is so helpful.

Another advantage is the indoor and outdoor usage. Some -40°C won’t bother this unit. The charger is weatherproof, which is very important if you need to use it while you are on a boat or during the rainy season. Its case has wall mounts, so you can easily install it whenever you want. It is included 6ft or 180cm AC supply lead and 6ft or 180cm charge lead ending in SAE connector. A standard battery clip set is also included. The design is fully sealed.

Another good side of this  Tecmate OptiMate 6 charger, is the early warning of battery problems. Something helpful is that this charger includes 24/7 automatic storage control and optimization of battery power and life. The unit weighs 3 pounds, and its dimensions are 12.3 x 7 x 3.4 inches.


  • Battery save function
  • Waterproof and fully sealed design
  • No manual control, the unit is fully automatic


  • The lights and status of the product may be hard to understand

7. BMK BLUEMICKEY Smart Battery Charger Portable Battery Maintainer

BMK BLUEMICKEY Smart Battery Charger Portable Battery MaintainerBMK 12V 5A battery charger is suitable for charging batteries from 15 to 100Ah. If you own battery over 100Ah, this charger will fill it to 100%, but it will need more time.

Made of high-quality ABS, IP65 and its waterproof design this little guy will give you a hand in many situations. One useful feature is the constant pulse current maintenance function, which will avoid overcharge and discharge to your cell.

There are 4 stages of automatic charging process by MCU controller and LED indicators. By them, you can indicate the quantity of electricity and monitor the whole charging progress. The charger will stop automatically when the battery is fully charged, there is no need of manually operating.

This BMK battery maintainer charger is suitable for a lawnmower, boat, car, motorcycle, electric vehicle, electric tools and especially it is perfect for emergency battery charging. The unit is lightweight, with only 1.76 pounds. This allows you to take it everywhere with you. It can be used as a trickle battery charger as well. The package dimensions are 9.5 x 4.6 x 2.9 inches.


  • Multifunctional
  • Lightweight and mobile
  • Waterproof


  • Batteries under 15 Ah may not be charged well

8. MinnKota MK-105P Portable Battery Charger

MinnKota MK-105P Portable Battery ChargerThis MinnKota MK-105P is a portable 12-volt battery charger, which is suitable for charging all kinds of electric motor batteries. It has 1 bank with 5 amps. The unit is fully automatic with 2-stage charging, so there isn’t any need of monitoring it and manually stopping it when your cell is charged.

Its smart and durable system protects your cell against short circuits and reverses polarity problems from improper connections. This charger keeps you on the water longer and won’t overcharge or undercharge your battery so you can practice your favorite hobby longer. Useful features are the LED indicator lights for a simple and convenient charge. It has light-up buttons telling you if your connection is right if it’s charging and when it is done the loading.

This unit is made in handle design, which makes it easy to transport to the battery. Its dimensions are 8.2 x 8 x 6.9 inches, and it weighs only 4.12 pounds.


  • Small, lightweight and compact charger
  • Charges fast
  • 3-year warranty
  • a lot of safety features


  • The charger’s switch may make a loud clicking noise when switching between modes

may not detect the full charge and it will overheat

  • Sometimes the charger does not turn green when fully charged
  • It’s not technically portable unless you have an outlet on your boat

9. DuraVolt Marine Solar Panel Battery Charger

DuraVolt Marine Solar Panel Battery ChargerThe excellent feature here is the universal “Plug & Play” design. The DuraVolt Marine Solar Panel Battery Charger is easy to install without any prior solar experience. It is fully weatherproof, and it’s ideal for boating and camping. The unit is lightweight, nobody wants to carry heavy chargers. Another good feature is “non-glass construction,” which calms you it won’t break. Note that it is made of an unbreakable plastic film surface with semi-flexible aluminum backing. These make this panel ideal for mounting it on flat or gently curved surfaces.

I case you want to put it on a comfortable accessing place, on the panel, there are 4 mounting holes for fast installation. The charger includes an outdoor rated power cable that connects directly to your battery through the factory installed fused cigarette lighter plug.

This charger can fill 1 small battery ( for example a Jet Ski size). You can use it for small-sized lights, radio, phones, and other electronics. Also, DuraVolt panels are designed to provide reliable solar power for rugged marine and other outdoor applications.


  • Very handy
  • Easy installation
  • It works by a solar system, no electricity needed


  • You must consider the sunlight if it is not sunny enough; this charger will not cover your needs.

10. Schumacher XCS15 Ship and Shore Battery Charger

Schumacher XCS15 Ship and Shore Battery ChargerThis charger is suitable for all your needs because it’s appropriate for cars, trucks, marines, RVs, farm types of equipment, AGMs, even gel cells and deep-cycle batteries. There are a lot of functions and indicators on the front panel. Some of them are the charger monitors that let you know what’s going on with your cell.

Also, the indicators for battery condition and the adjustable charge rate are very helpful to prevent battery damage. This unit is a three-stage charger, which means it has three different ways of filling the cells- fast, middle and low rate. If you have to charge small, or you need to maintain large batteries the 2 amp slow charge will do the work. The other self-adjusting charge rate is perfect for everyday charging needs, and it always keeps your battery in peak condition.

The  Schumacher XCS15 charger automatically determines when the connected battery is a 6-volt cell or a 12-volt cell, which is a beneficial and useful feature. This charger weighs only 2 pounds. The dimensions are 10 x 10 x 4 inches. These two characteristics make it really mobile and lightweight.


  • Multifunctional
  • Adjustable charge rate
  • Automatically detects the voltage of the battery
  • Lightweight


  • Sometimes when you set the charger mode, this unit may change it by its own.
  • Needs restarting

Types Of Marine Battery Chargers

Best Marine Battery ChargersThis is an essential thing to know because not every kind of charge on the market will be able to work with your batteries. So, to introduce you a bit, AGM and gel cells need specialized, high-quality chargers, such as smart or microprocessor-controlled types if you want to use them for a long time. However, if you are looking for something simpler, lead-acid is the way to go. They are suitable for flooded batteries, but you should be careful about how you handle them. If you forget the charger, it can boil off the flooded cells and kill the whole array.

A lot of people recommend getting a smart charger because it thinks about the temperature and battery chemistry when you are using it. Besides, to that they make sure you get a full charge, thanks to their three phases cycle, this also makes sure your battery doesn’t get damaged. They are rather cheap and worth buying since they extend the life of your battery.

Overall, you decide the most excellent type of battery charger, depending on your marine battery, to categorize them they can fall in one of two categories:

  • Manual Charging

As the name suggests, you turn them on and off by hand. You also have to alter the voltage and current.

  • Automatic Charging

In contrast, for the electronic type, you don’t even need to be there, because they can sense the inner current and voltage, plus they will switch off once the battery is ultimately charged.

Their Benefits and Drawbacks

  • Advantages

  • An onboard charger has power in their technology because they have multistage switching, this will safely charge and sustain your batteries, even throughout their charging process. They are also appropriate if you have one or more fine trolling motor batteries.
  • The linear type of charging is very reliable, simple, it has a vented design and can reduce heat.  This type is often water-resistant, but it is well placed in a watertight, moisture-free part of the boat.
  • Electronic chargers can adapt and service a deep-cycle marine battery as well as one which is of a cranking type.
  • In the case of a smaller boat, portable chargers are more comfortable to use. This is the same if you want to charge multiple ships.
  • Disadvantages

  • Onboard chargers are more on the expensive side of things, compared to the portable type.
  • Due to their bulkier dimensions, you need to provide a bit more space for a linear charger.

What Should the Battery Size be?

This question is asked in regards to how many amp hours your battery store, not its physical dimensions. An example is a good deep-cycle marine battery rated at 100 amp-hours. If you are unaware of what this means, feel free to visit our guide related to such batteries. To fully recharge with a 10-amp charger, it would be 11 hours, assuming the battery is dead.

The rule of thumb which can be really useful in calculating the complete charge time is, dividing the ampere-hour rating of the battery by the charger rating (amps) and adding about 10% of the additional time to top off the battery completely.

If you want a faster recharge, you should look at chargers with more amps. But if you don’t need or want to hurry, you can get a smaller unit. The essential thing here is that in your assigned time your charger manages to load your item.

Features To Look For When Buying A Marine Charger

Marine Battery Charger ReviewsWhen choosing any kind of product there are always some things we should consider, which are more of a fundamental nature about the specific item, or sometimes it’s some standards that have to be met. Now we will take a look at those things when it comes to marine battery chargers.

  • For the marine industry, the standards are ABYC/ UL 1236, which have to be met by the charger! To make sure such an item has met the criteria it has to undergo a 1500 volt test, which shows if there is an appropriate AC/DC isolation inside it.

Some people can look into non-marine chargers for their boats, and some of them do well with the environment, but if you search for those who have the ABYC or UL 1236 compliant statement or logo you can rest assured that it is well suited for water application.

  • You have to look for a charger that doesn’t have a limit on the output; meanwhile, it should be able to work with different input voltages. This means it should supply you with 100% of its rated production while working with any voltage between 90-260 volts/ 40-80 Hz. This is a “World Voltage,” Sterling PCU power factor for chargers.

This is great because if you travel anywhere in the world, you could use the charger freely. That can be a good plus for anyone who loves to cruise, meanwhile if you have a US voltage charger, you are stuck with using it at US docks only.

  • In an ideal scenario, you will get your hands on a battery with a temperature sensing which physical on-battery is, and that shouldn’t be an extra; instead, it should be as a piece of standard equipment.
  • Something which isn’t specifically a must, but does make things easier on you is if you find a charger, which has both an excellent reputation for the manufacturer’s customer support/service and a good, great warranty.
  • A charger that can use multiple choices for charging profiles and voltages comes with it’s the benefit of being flexible when using different outputs. Plus the capability to create a charging profile, which is custom is a bonus.
  • When it comes to the stages a charger can use, we recommend you to find at the minimum one which has a multi-stage one with Absorption, Float, and Bulk. However, if you are able to get more options such as equalizing and conditioning are good ones.
  • Since we are talking about a marine battery charger, logically following that means it should work well with marine generators. This is another note to think about if you are looking at non-marine items because it’s not often that such a unit can work well with marine gen since they don’t output a clean sine wave all the time. If what you are eyeing has a Sterling factor, then it will handle sound generators with a bit off specs.
  • If you are looking for a battery which we are able to charge wet cells, you have to seek out one which is able to periodically turn back to an absorption voltage, if it’s in float/standby option. This program minimizes electrolyte stratification. Just having a float voltage isn’t enough to stop stratifying the electrolyte. However, if you have an absorption voltage, which runs shortly from time to time, this will prevent those effects and will in turn re-mix the electrolyte.

To explain why this is important, let’s take a look at what stratification is. You can see if this happens to you if the acid has sunk to the bottom of your battery case, while at the top you can see the water has risen. This creates uneven plate wear and can cause premature death to your battery. This is where cyclic absorption is handy, because it will get things moving again, but not all chargers have this feature.

Installation of a Marine Battery Charger

You can always look up ways to install your marine battery charge painlessly, and how to fix it within the manual you get with the product itself. However, we will go through all the steps briefly as well. Keep in mind that some chargers come with an AC lead which is already connected to the charger.

  1. In a dry and well-ventilated place mount the charger with self-tapping screws or stainless-steel nuts and bolts.
  2. If you have a charger with a maximum output of 2- amps, for instance, use a fuse that is a bit bigger, just like a 25-amp terminal-mounter fuse.
  3. To make a connection waterproof, before doing the crimping, cover the joint by slipping a length of heat-shrink tubing. Warm it up with a hot-air gun or a hairdryer. Then terminate wires with crimp-on ring terminals. You can use cheaper crimp-on tools, or you can invest in double crimpers, which will obviously perform better.
  4. Every 18 inches or so all cables should be well supported. You can use cable ties, plastic clips or any other type you can find.

After you’ve connected the DC well enough, look at the AC side. You might need to add the first connection if it lacks having one. Check the installation instructions for the wire size, always make sure they are supported by saddle clips or wire ties.

Marine Battery Charger Maintenance

Maybe you’d be surprised to hear that even the marine batteries that do not require maintenance need a little bit of support, just like any other part of your boat. We’ve covered a wide array of marine accessories and supplies in our guides, and they all require care to perform well all.

Some that are considered maintenance free are the AGM batteries because they are sealed. However, you should watch it during a re-charge. You need a smart charger. Otherwise, some damage can be done to the unit. You have to remember that the flooded acid type needs to be kept full. You have to top them off only with distilled water because it is neutral, tap water has minerals, meaning electrolyte is in the liquid.

Something you have to do is check on the terminal clamps, they have to be kept clean and free of any corrosion. You can soak them with either petroleum jelly or a spray that prevents corrosion. The connections should be tight, and also keep an eye on loose connections and fix them. All of those things will ensure your battery is top-notch.

Our Safety Tips

  • First and foremost you should read your manual guide. There you can find instructions for how to maintain your marine battery.
  • Before connecting or disconnecting the charger to the battery, it should be unplugged.
  • You should charge the battery in a well-ventilated area.
  • In the case of a flooded battery, you should charge it if the hydrometer reading is under 1.225 of specific gravity, and the load test shows beneath 9.6 volts (or if it’s open circuit under 12.4 volts). At the same time, you should keep an eye on it, so it doesn’t charge for more than 48 hours.
  • At all times, even more so during a charging period, the battery should be stored away from any flammable or igniting substances.
  • If you see that the battery starts to overheat, carefully remove the charger and get in touch with the manufacturer for what might be the reasons.
  • Keep the battery unit clean, dry and fresh. In the case of corrosion, you can use a paste of water and baking soda.
  • The same goes in a situation where the voltage and hydrometer readings have not shown any change after around two hours of charging. Remove the charger and consult with the company.
  • The battery should always be around 60o degrees warm before charging. Never load it if it’s frozen.
  • To guard your hands against acid, when you work around the battery, make sure you use gloves.
  • Make sure you always use the same type of battery on your boat. Otherwise, if you mix types the life of your battery tank will shorten.
  • To not lose conductivity always make sure the terminal connectors are clean.
  • Don’t leave any battery uncharged for a long time, if you move it in such a state it can lead to sulfide damage and lower its capacity. Charge them after every time you use them.

Wrap Up:

Congratulations! The worst part is over, you now know all the information you need, to find the best marine battery charger. And, we are sure that with our reviews on the best marine battery chargers, you will not have a problem finding what you look for.

We really hope that this piece has helped you. If you enjoyed this article and you think it was useful, don’t forget to share it with others. Our comment section and email address are waiting for you if you want to share anything with us.

Helping our readers is our number one priority. For this reason, we have many other articles devoted to finding the most reliable unit and if you think this one was useful, go check the other ones as well. Thanks so much for reading, and as always- stay put!

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