Nothing shortens a battery’s life more quickly than having it without an on-board trickle charger. Before your boat’s battery dies in the middle of the sea, you should make sure that it has been properly charged by a battery charger. Given the fact that there are several types of batteries and all of them have different uses and require specific charging requirements, therefore, it is crucial to buy the best boat battery charger and make sure it can provide the correct charge at the right time.

Here at Globo Surf, we have looked at the boat battery charger reviews to make sure that we have the top rated marine battery charger that will be the perfect fit for your boat. We explore the key features and answer the important questions to give you the information you need to choose the best marine battery charger

How To Choose A Marine Battery Charger – Buying Guide



It is important to make sure that the marine battery charger can provide the right amount of voltage for your battery. Marine batteries usually run off a 12V system, however, this might not always be the case. The battery should be capable of various charging powers and has the ability to charge at both 6V and 12V. There are batteries where you can switch between the two voltages automatically. It’s important to check your battery to ensure that the charger you are getting will be a suitable fit.


There are many different types of batteries out there such as flooded lead-acid batteries, AGM, gel, and lithium-ion options that have different charging requirements. Most of these marine battery chargers we have reviewed support a number of different battery types but you shouldn’t presume that your type is going to be covered. The best marine battery chargers have microprocessors that are able to read your battery type and adapt its amperage and voltage to meet its demands.


If you’re taking your battery charger on a boat with you, you need to have one with a higher level of durability. Being able to withstand shocks and having waterproof protection are also exceptional additional features. Others may want a much more sedate environment where they will be used to recharge the battery when it’s not being used or trickle charge it during the offseason. 


One of the most obvious criteria is the protection against reverse polarity which all battery chargers need to have in order to protect their users. Other key safety traits include having the right amount of fuses as well as protection from too much current, voltage, and temperature. It’s important to have these features especially considering that your battery charger will most likely be left alone for a long period of time.

Charging Time

The charging time of your battery depends on the size of the battery as well as the type of battery. Type plays a huge role as each battery charger accepts a different kind of amperage so having a defined time for your battery charger depends on a number of different circumstances. The more powerful your battery charger, the more quickly it will charge your battery. 


If you have multiple batteries then it is better to have a battery charger that has numerous banks so that it can charge a number of batteries at the same time. This will come handy especially for those that have both a deep cycle and a starter battery as well as for those who have a larger vessel with a number of different batteries. If you think you might want to add some extra power in the future then giving yourself the option of an extra bank might be wise.

Recovery Time

Recovery time is determined by your battery’s ability to recover its charge after it has been fully drained. Generally the higher the amperage that your charger can give, the quicker it recovers your battery. The importance of this depends on how often you use your battery and how much you use it. The best chargers fully recover your battery in just a few hours whereas others take a lot longer. If you will be using your boat for multiple days in a row then it is better to have a battery charger with a quick charging ability.

On-Board Vs Portable Boat Battery Chargers

If you have a smaller vessel, having a portable model is ideal as you wouldn’t need the same level of power. If you have a larger boat with more than one battery, then getting an on-board charger is better as you will be able to charge a number of different batteries time and time again. This would allow you to have a constant power source so that you never run out of charge.


Larger batteries are more powerful and offer more features such as a larger range of banks. You want to select a size that is going to be compatible with your boat and easy to store. If you have a portable battery charger then this will obviously be much less of an issue as long as it’s light enough to be moved from one place to another.

Power Source

An on-board battery charger requires access to a shore power unit when you are docked up if you will be leaving it on the water overnight. If you’re the type of person who makes use of the boat for a day and trailer it back home, then this isn’t a requirement. This is also where portable chargers have their advantage as they can be powered up in the comfort of your own home.



Q: Can I charge a deep cycle battery with a regular charger?


No, it is not convenient to charge a deep cycle battery with a normal charger. Here are some of the reasons:

  • Deep cycle battery plates are much thicker than normal battery plates and sulfate formation is low. However, normal batteries have thin plates, and the amount of sulfate increases gradually.
  • A deep cycle battery needs to be charged slowly. A normal battery charger typically charges at 2 amps in slow charging mode and 10 to 15 amps in the fastest charging mode. The deep cycle battery charger is compatible with 2 amp charging speed, perfect for the battery. 
  • Deep cycle batteries generally have larger storage capacity, so it may take longer to charge than conventional batteries. These increased amp storage capacities cause the battery to overheat while charging. For this reason, a deep speed battery charger usually has a safety system that allows it to shut down when the battery reaches a very high temperature.

Q: How do I choose an onboard battery charger?


When choosing an onboard battery charger, it is important to choose a device that is compatible with your battery. You have to consider important features such as type, input voltage, amp-hour capacity, and the environment you will be using the battery. The biggest destruction for batteries is overcharging. If possible, an internal and intelligent battery charging and maintenance device should be preferred for such batteries. Charging time is a determining factor in this regard, as well. More discharged batteries or smaller alternators require more time for a charge.

Q: What is the best way to charge a deep cycle marine battery?


A deep cycle battery can be charged in two basic ways. The first method is to charge the battery where the charging source is stationary, and the other one is to use a portable charger. A deep cycle battery is mostly used outdoors. Therefore, it needs to be charged both at home and outdoors.

Q: What Size Charger Do I Need for My Deep Cycle Battery?


The size and the type of your battery are two important factors as the more current you put into your battery the quicker it charges. There is little point getting a heavy-duty charger if you only have a smaller battery. The total amperage that your battery can accept also depends on the type of battery.

A flooded battery is generally the least efficient type and only accepts a charge rate of up to 25 percent of its capacity. A gel battery is a little bit better and accepts a charge rate of 30 percent. The most efficient battery is an AGM battery which is able to accept the highest amperage of the three and can take 40 percent of its capacity. If you’re looking for a quick charge, then look for a charger that has more amps. If you get a great charger and have a flooded battery, then this won’t be able to charge as quickly if you put the same charger on an AGM battery.

Q: How Many Banks Should I Have On My Charger?


In simple terms, the number of banks refers to the number of batteries you can charge at the same time. If you have a smaller boat and only have one battery then you don’t have to worry about how many banks your charger has. The general rule is that you want to match the number of banks that you have with the number of batteries that you have, whether that is one, two, three, or four. If you think you might expand your electronics then getting one more bank than you need at the moment will mean that you can be more prepared for the future.

Q: What Should I Do If My Battery Charger Overheats?


The best way to stop your charger from overheating is to buy a quality charger in the first place. The best chargers on the market have in-built safety systems that prevent them from overheating and have temperature controls that match them to their climate. A lot of marine battery chargers have microprocessors installed which can read what your battery needs. These battery chargers also detect when a battery is fully charged and switch from a fully charging mode to a trickle charge mode.

Globo Surf Overview

Getting a top rated marine battery charger means that you will be able to charge your batteries easily with a high level of safe performance. A battery is vital to your boating experience and hopefully, one of the battery chargers on our list is the one you are looking for.

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Globo Surf
My name is David Hamburg. I am an avid water sports fan who enjoys paddle boarding, surfing, scuba diving, and kite surfing. Anything with a board or chance I can get in the water I love! I am such a big fan I decided to start this website to review all my favorite products and some others. Hope you enjoy!