Best Marine Battery Chargers – Always Stay Charged Up

Power supply on a sailboat can quickly become a concern if you sail for long periods. Equipping your sailboat with a solar panel or a wind turbine is not always easy. But installing a charger for marine batteries can be an excellent option.

Chargers for marine batteries differ mainly in the housing protection class compared to conventional car chargers. We have picked the five best marine battery chargers for you and in this article, we will review them to see their key features, how they work, and their pros and cons.

Marine Battery Charger Reviews 2022

1. NOCO Genius GEN5X2 – Editor’s Choice

The Noco Genius GEN5X2 is one of the best battery chargers on the market. It is both versatile and multifunctional. It is an onboard battery charger that is compatible with 12V lead-acid, deep cycle, lithium-ion, AGM, with or without maintenance, etc. It incorporates many useful and practical functions which include thermal sensors, force mode, LEDs, etc. In addition, its use does not require any special knowledge.

Compact, light, practical and above all efficient, the Noco Genius is the best-selling boat battery charger on the market.

As usual, the American giant offers us a product that satisfies at all levels. The Noco GEN5X2 is a 2-bank battery charger that is an excellent option for recharging different types of batteries as well as for desulphurating them.

This versatility is also highly appreciated by consumers who leave a multitude of positive reviews, in particular for its safety features, weatherproof quality, and ease of installation.

However, note that when purchased, it doesn’t come with interchangeable connectors or clamps like the Noco Genius 2. But it comes with two self-tapping screws and a user guide.

This product from the famous brand Noco connects easily and its use is without difficulty. Fully automatic, you just need to select a charging mode to start charging your car or boat battery.

The Noco Genius is a device compatible with all types of batteries, from Lithium-ion LifePO4 batteries to lead-acid and AGM batteries. It is also capable of recharging a nearly empty battery down to 1V. It works with different types of vehicles: boats, motorcycles, classic cars, electric bicycles, mowers, etc.

More than a charger, the Noco Genius GEN5X2 is an efficient battery desulfator. It automatically detects any presence of sulfation and acid stratification of the battery. It provides optimal desulphation that restores lost performance to enjoy more powerful starts and a healthier battery.

The charger is also equipped with a thermal sensor which, depending on the ambient temperature, regulates the charge level. This is manifested by the elimination of overload in hot weather or underload in cold weather. Click here to see the best price.

Key features

• 2-bank onboard battery charger
• Battery charger, maintainer and desulfator
• Deep cycle charger
• 12 volt 10 amps

2. ProMariner ProSport HD – Best Multiple Bank Charger

The ProSportHD series from Promariner was specially developed to be used in sports and electric boats. ProSportHD chargers offer two or three equivalent charging outputs for 12/24 V and can also be used as fully-fledged power supplies.

The ProSport HD 20 has a microprocessor and software-controlled charging technology for fast and accurate charging. The charger works with the new proprietor digital technology, which ensures compact dimensions, low weight, and maximum efficiency.

The charger has a waterproof design thanks to its dual inline waterproof fuses. The five-stage charging characteristic guarantees a highly effective charging process and the best possible utilization of the existing battery capacity including the trickle charge function. The battery charger is suitable for lead, gel, and AGM batteries.

100 percent of the available charging amperes are used by distributing charging amps that are unused to any battery. It has a top, bottom, and rear heatsink design which ensures optimal cooling with true constant current load amps while on the two-charge mode.

What is more exciting about this charger is the fact that it charges various batteries. You can use it in gel, AGM, or deep cycle batteries. Likewise, despite its unique features, it is affordable. Its operation and maintenance are uncomplicated and you are guaranteed to benefit from its services for many years. Click here to see the best price.

Key features

• 5 stages of charging
• Isolated battery outlets
• NEMA 5-15 AC plugs
• Triple bank charger
• Multi-stage charging mode
• Reverse polarity and short circuit protection

3. Schumacher SC1280 – Best Smart Charger

Schumacher is a household name when it comes to durable automotive and boating accessories. The Schumacher SC1280 is currently one of the best battery chargers for boats and automobiles on the market.

The SC1280 will keep your batteries topped up. It can output 15A, and when the battery is sufficiently charged, it will switch to a trickle charge of three amps. Switching between increased charge and the slow charge is automatic.

The automated voltage switching feature switches between 6V and 12V, depending on the type of battery connected to the charger. For this reason, it is one of the most reliable options on the market.

These nifty features together can ensure your batteries last a long time. The Schumacher SC1280 automatically drops the current when the battery is over 80% charged; this safety feature ensures that the battery does not overheat. Avoiding overheating can extend battery life.

There is a downside, however. The charger may think a battery is 100% if it is dead or not accepting a charge. So it will reduce the current to three amps and the voltage to 6V to enter hold mode.

The Schumacher SC1280 automates so much that the only thing left for the user is to just plug it in and let it handle the rest.

The fast battery charger can be used for automotive and marine batteries. It has a 15A maintainer that keeps charging slowly to maintain the level. It also features reverse connection protection that ensures the charger doesn’t charge if you mistakenly reverse the clamp.

The charger can automatically detect the voltage of a 6 volt or 12-volt battery. It will also automatically determine the charger rate of the battery. Unlike other battery chargers, it features an integrated reverse connection for protecting the charger from damages caused by an incorrect battery polarity. The battery charger is a compliment to the DOE and it used the advanced technology from the brand. So, it meets the highest standards in the industry. Click here to see the best price.

Key features

• 15 amp fast charge
• Tri-amp trickle charge
• Automatic voltage switching
• Automatic current control
• Reverse polarity protection

4. NEXPEAK Battery Charger – Best With Safety Features

It must be admitted: finding a cheap marine battery charger that is reliable and of durable quality, is not always easy. Because many entry-level chargers are either too basic or of questionable quality. However, there are excellent models at low prices, like this Nexpark smart charger. And what’s more, it has a nice design!

But it is above all its performance and its low price that have pleased many users, who have frankly praised its remarkable quality. First of all, on the voltage side, this battery charger can adapt to two different voltages: 12 volts and 24 volts.

Also, if you need a versatile and inexpensive battery charger, this is it. The Nexpeak device is ideal for charging and maintaining batteries of cars, trucks, motorcycles, lawnmowers, motorboats, tricycles, electric vehicles, SUVs, marine, etc.

The battery desulfator adopts the latest pulse repair technology, restoring battery power or improving it to avoid further annoying battery outages.

The device has a lot of protective features, including smart control, temperature compensation, reverse polarity protection, efficient cooling system, overcurrent protection, fireproof material, overvoltage, and short closure features. This is why it stays cool even after a long period of charging, you can even let it charge all night.

The first impression of the device after delivery is positive. It’s well packaged and delivered with an instruction manual. The respective description of plus and minus is given on the clamps so that no mistakes can be made when connecting the respective battery.

The display is illuminated and self-explanatory. The device can also be used to charge and discharge the lawnmower battery over the winter. The repair mode works without any problems. When charging, a slight humming can be heard, which comes from the built-in fan. This ensures that the device will not overheat in any case.

The price-performance ratio is perfectly fine as it currently sells below $50. The downside of this charger however is that empty batteries cannot be activated or charged.

The 220-volt cable to supply the device with electricity for charging could be a little longer. Also, it’s not compatible with lithium-ion batteries. Click here to see the best price.

Key features

• 7-stage fast charging
• Battery desulfator
• Smart control
• Temperature compensation
• Reverse polarity protection
• Overcurrent and overvoltage protection
• 12 and 24 voltage

5. Schumacher SC1359 – Best Fully Automatic Charger

The Schumacher SC1359 is a battery charger and maintainer that uses 15 amps to charge and 3 amps to maintain the battery. The battery charger has an automatic voltage detection that automatically detects 6 or 12V batteries.

In addition, it has reverse hook-up protection which ensures the charger won’t operate when the clamps are in reverse position. You can use the Schumacher device to charge compatible battery types including standard, AGM, and deep cycle batteries.

The Schumacher SC1359 is a fully automatic battery charger that can also maintain battery charge. The product is also an automatic desulfator and can detect battery voltage automatically.

Asides from that, the amperage rate is automatically adjusted by the microprocessor. It’s a multistage charger for improved precision, longer battery life, and safety. The charger has an LED digital indicator with simple button control that makes it quite easy to use.

It’s also a versatile charger that can be used for charging car, truck, SUV, marine, and recreation vehicle batteries. Click here to see the best price.

Key features

• Battery charger and maintainer
• 15A to charge and 3A to maintain battery
• Battery controlled by a microprocessor
• Multistage charging
• Automatic voltage detection
• Reverse hook-up protection

Things To Consider Before Buying a Marine Battery Charger

Finding a good marine battery charger is not always easy because there are many models at all prices, and all claiming to be the best in the world!

Great care must be taken when choosing the charger model you want to use for your marine battery so as not to run the risk of damaging the charger, the battery, or worse, causing a fire outbreak. A good charger should be able to pass all performance tests. This is why making a comparison is important to see the best models.

To avoid buying a device that does not suit you, here are some important points that are really important to check before making a purchase decision. Otherwise, you are very likely to pay the price!

Voltage

Yes, it may sound silly, but all battery chargers do not necessarily have all the voltages you want. As a result, one of the first things to do is to check that the battery charger you plan to buy is compatible with the nominal voltage of the battery to be recharged.

In general, automotive batteries have a voltage of around 12 volts (12V), but always make sure that this is the case for your battery too, in particular, before any purchase.

Also, we advise you not to take a 12V charger to charge two 6V batteries connected in series. Of course, it could work, but the chargers could just as well malfunction or it could even damage your batteries if they are not in the same state of discharge, or health.

This is also the case if you have two 12V batteries and a 24V charger. In any case, do not play the sorcerer’s apprentice with the batteries, whatever they are, because the risks are very real, and must be taken very seriously!

Also, the charging current of a charger should correspond to one to three-tenths of the battery capacity. If the power of the charger is in this range, the battery is charged steadily and yet as quickly as possible.

A charger with a charging current of at least 10 A should be selected for a 100 Ah battery. If power-consuming devices with a total current consumption of 5 A are active during charging, we recommend a charger with a charging current of at least 15 A.

With a 100 Ah battery, the charger should not exceed the charging current of 30 A. Of course, the power consumption of the consumers should also be taken into account here.

Using two chargers on your boat is practical and often cheaper than using one charge controller. The higher the charging current, the faster the battery is charged.

The high charging current of 25 A leads to an incredibly fast charging of the battery. How large the charging current must depend not only on the battery capacity but also on how much time you want to plan for charging the battery. .

Smart Charging

A few years ago, battery chargers were simple voltage transformers, delivering a voltage a little higher than the nominal voltage of the batteries. And of course, this proved more or less effective, because there was no dynamic adjustment of the voltages and currents of charge.

This is why we have seen the development of so-called “smart” battery chargers in recent years. They are even capable of ensuring the desulphation of the batteries, with a view to cleaning them properly.

Thus, the charge can be done fully, and the batteries are thus maintained, in a way!

Charge Time

This criterion is very important when selecting the right product, since there have been multiple cases in which 1A is confused with 10A, and as you know, 1A would have a too slow charging process. While 10A would charge the boat battery much faster, a lower-rated charger will mean slower charging.

How long a charger takes to charge a battery depends on the number of amps per hour (Ah) that the battery has. If it were 10 amps, on average it would take 45 minutes. Whereas if it was a 2 amp battery, it would take about 24 hours to fully charge. However, on average, the boat battery takes between 4 to 6 hours to charge. But again, it depends on the charge capacity of the battery charger.

Therefore, the more amps the battery has, the faster the charge will be. Knowing this, the power of the charger should be carefully checked, choosing the one that matches the amperage of the battery. The most common amperages in cars and boats are between 40 and 110 amps.

Safety

Being that they will be used in an environment where emergency services are not nearby, a boat charger must have all the necessary features, provided you don’t want to end up swimming for dear life following a fire outbreak. Also, a marine battery charger must be waterproofed.

IP class

Boat chargers can get wet or damp more often than car chargers which are mostly used in dry environments. The housing protection class for a charger provides information about how the device is protected against touching live parts, moisture, and other environmental influences.

The IP class of a charger thus determines which environmental influences the device may be exposed to without it being damaged or causing a hazard. Depending on the application, you should pay particular attention to the IP class when buying a marine charger due to the wet environment. The recommended ingress protection (IP) range for marine chargers is between 61 and 68.

Temperature Sensor

A marine charger with a temperature sensor is definitely recommended. The heat generated during charging alone can result in serious dangers.

The battery, but also the charger itself, heats up during the charging process. This is usually not a problem if the room is well ventilated and the heat can be dissipated. However, if several factors come together, it can certainly lead to a fire.

If, for example, the wrong charger without temperature monitoring and with too high a power is used, this can lead to excessive heating. Direct sunlight and unventilated charging areas should also be avoided. Our recommendation for your boat is the use of marine chargers with a temperature sensor.

Compatibility

Always be careful to only use a charger suitable for your type of battery (lead, AGM, lithium, etc.), corresponding to its nominal voltage (6 volts, 12 volts, 24 volts, etc.) and its maximum intensity. Otherwise, the risks for you and your environment could be very severe. So show maximum vigilance and discernment to avoid any problem that could harm your health or your environment.

Use as specified

Also, be sure to always strictly follow the conditions of use of each charger, written down in the manufacturer’s user manual. Never assume that all chargers work the same, as this is far from true. Similarly, do not use a device for which you have not read the manual, or do not know its practical use.

Finally, do not take lightly recommendations such as good ventilation of the room where the battery will be charged, or any other advice given by the manufacturer. Because the risks are very real, despite what one might think, and should be taken seriously. Either way, be careful!

Repair Mode

The Repair Mode is a special feature in marine batteries. The function which we have seen on many medium and high-end battery chargers.

With this feature, it is now possible to bring back to life batteries that discharged, or at the end of their life. Thus, you can save a lot of money by increasing the durability of your batteries, simply by using this mode. However, don’t expect any miracles. Because a dead battery will not be revived!

Power Source

Today, there are many possibilities for charging the batteries of your sailboat. Between the engine alternator, wind turbines, solar panels, and even hydro-generators, there are many solutions to be autonomous in terms of energy production and recharge a boat battery.

However, these solutions are not suitable for all boats. While some solar panels adapt very well to all boats, their power is often low. At the same time, wind turbines are reserved for boats over 10 meters. Below that, they could be dangerous or be disproportionate to the size of the sailboat.

FAQs

Do marine batteries need a special charger?

Although marine batteries can be charged with a car battery charger, that's not always safe to use. A marine battery is best charged slowly unlike a car battery. Also, your marine battery charger should have safety features such as temperature compensation, IP 61 to 68 protection, an efficient cooling system, overcurrent, and over voltage protection.

What is the best amp to charge a deep cycle battery?

The marine battery charger for your deep cycle battery must be able to supply about 10 percent of the maximum amperes of the deep cycle battery. So, if the battery is rated as 100 amps per hour, the charger must be able to deliver up to 10 amps.

Can I use a trickle charger on a marine battery?

Trickle chargers are ideal for marine batteries and even better than fast car batteries as they do not generate excess heat. Overheating is prevented, safety is ensured and the battery will last longer.

Can a car alternator charge a deep cycle battery?

A car alternator will not fully and properly charge a deep cycle battery. So, it's better to have a solar system with a charge regulator or controller.

Final Thoughts

The maintenance of a battery is important for comfort on board, safety, and avoiding changing the battery too often.

In any case, cheap battery chargers that are used for automobiles should be avoided. These are designed for emergency recharging on starter batteries, but cannot properly recharge the battery of a sailboat.

In any case, the best marine battery charger must be compatible with your type of battery and have all the safety features mentioned in the article.

It must have at least a three-phase charging curve. It must be waterproof and have overcurrent and overvoltage protection. Finally, a built-in cooling fan is important to prevent overheating by dissipating heat.