The 6 Best Marine Battery Chargers & How to Choose the Right One

This guide will introduce you to some of the top models of marine battery chargers available. Check out our product comparison below, or scroll past the overviews to read our full guide to marine battery chargers.

The Best Marine Battery Chargers in 2022

If you are looking for a 2-bank marine battery charger that does it all, the NOCO Genius GEN5X2, 2-Bank Smart 12V Onboard Battery Charger will impress you with its flexible design and smart features.

Key Specifications

• 9.15 x 7.2 x 5.39 inches
• 10 amps
• 2 banks (5 amps each)
• Charging modes: 12V, 12V AGM, 12V Lithium, and 12V Repair Mode

What We Like

• This two-bank marine battery charger offers impressive versatility with its range of different charging modes. It is compatible with pretty much any type of battery you might have.
• You can mount this battery charger in just about any orientation you might need. The compact dimensions also make it a great fit for small spaces.
• With its IP68 rating, this sealed battery charger is waterproof and safe to use in your vessel.
• This product includes an abundance of great features such as auto repair, auto-detection, and an integrated thermal sensor. You can expect excellent accuracy every time you charge, no matter the weather.

What We Don’t Like

• While you can charge two batteries using this device, you cannot do so if they are in parallel.
• If your batteries are not located near each other, you might not be able to reach them with the cables. So, this product may not be a fit if your batteries are at opposite ends of your vessel.

If you liked the NOCO Genius GEN5X2, 2-Bank Smart Charger, but need something with an additional bank, then try the NOCO Genius GEN5X3, 3-Bank Smart 12V Onboard Battery Charger.

Key Specifications

• 7.1 x 5.7 x 2.2 inches
• 15 amps
• 3 banks (5 amps each)
• Charging modes: 12V, 12V AGM, 12V Lithium, and 12V Repair Mode

What We Like

• Like the 2-bank battery charger from NOCO, this product has a compact design that packs an impressive amount of power.
• This product also includes auto detection, auto repair, and the thermal features of the 2-bank battery charger. Its compatibility and flexibility are on the same level, and it is likewise waterproof.
• If your batteries are under 1V, you can also use the product’s Force Mode.

What We Don’t Like

• You can easily screw up and void your warranty when adding extensions if you do not carefully read the instructions.
• This product lacks alligator clips. Also, the charging cables may not reach far enough for everyone, and you cannot lengthen them.

Tired of clunky user interfaces on marine battery chargers? The ProMariner 44021 ProMariner ProSport HD Waterproof Marine Battery Charger with its clear, colorful LED display will be a breath of fresh air.

Key Specifications

• 16.4 x 8.7 x 6.3 inches
• 6-20 amps (depending on the version)
• 12/24/36 V (depending on the version)

What We Like

• Our favorite feature is the beautiful LED display. This gauge makes it effortless to check on the mode, completion status, battery status, and more.
• This is a smart charger that ensures accuracy when charging with the help of a microprocessor.
• No amps go to waste thanks to Distributed-On-Demand Technology. There is also an energy saver mode.
• To ensure this product can function great and offer a long lifespan, it features multiple heat sinks.

What We Don’t Like

• The manual confusingly states that you should not extend the cables. At the same time, the company sells cables. There are some users who have stated they have extended the cables with success. The company’s cables are likely fine, but check to make sure you will not void the warranty.
• You cannot use this product with lithium batteries.

The TowerTop Smart Battery Charger/Maintainer is a great budget purchase. We also recommend it especially to those who live in cold climates.

Key Specifications

• 8.66 x 5.71 x 4.53 inches
• 2/8/15A or 2/10/25A (depending on version)
• Supports 12V lead acid batteries: GEL, AGM and STD.

What We Like

• This product features a 7-step charging program that prevents overcharging and provides optimized results. A microprocessor ensures smart operation.
• There is a basic LCD screen. It is nothing amazing, but it clearly displays capacity and voltage.
• There is a special charging mode just for winter.

What We Don’t Like

• If you have a battery with less than 2 volts, this charger likely will not detect it. One workaround is to connect another battery that has sufficient voltage to be detected to the other in parallel.
• The clamps are low in quality and do not work well.

Despite the fact that 24 volts is not unusual on a boat, the vast majority of marine battery chargers on the market are 12 volts. We wanted to include at least one model specifically designed for 24 volts, so we chose the ProMariner 63180 ProNauticP Series 2430P.

Key Specifications

• 15 x 5.7 x 10.6 inches
• (100-250VAC/50-60Hz) global AC input

What We Like

• This charger provides you with 4-stage charging profiles that you can use according to your needs. These include Charge, Condition, Maintain, and Re-Condition. It detects the discharge state of the battery and auto-selects a conditioning time accordingly.
• The global AC input helps to keep power consumption to a minimum.
• If there is something wrong with the wiring or another issue, the battery charger will display an indicator so you know what is going on.
• This product will reduce its float voltage automatically if three days go by without a load exceeding 5 amps. That means that it is ideal for storage.

What We Don’t Like

• This model does not appear to be compatible with lithium batteries.
• Compared to most other battery chargers we have looked at, this one has a steep price.

We wanted to offer at least one recommendation for a solar marine battery charger and picked the MPPT 20W 12V Solar Battery Charger. You can read more about this and other solar marine battery chargers we suggest in our guide, “The 5 Best Solar Battery Chargers for Boats.”

Key Specifications

• 18 volts operating power voltage
• 1.1 amps operating power current
• 20.15″ L * 13.78″ W * 0.7″ H

What We Like

• In the past, this product could not be used with lithium, but it has received an upgrade, so now it is compatible.
• Even though this was designed to be an all-purpose battery charger for a wide range of vehicles, it has an IP65 waterproof rating, making it suitable for marine environments.
• With its built-in MPPT charge controller, this is a highly efficient charger.
• The kit that you receive with this product provides you with multiple connection types, making for a fast, easy and flexible setup.

What We Don’t Like

• This product can warp in exposure to high temperatures, so that is something to watch out for.
• While the waterproofing is good, you may find a gap between the frames. Just fill this up yourself to prevent leaks.

What to Look for in a Marine Battery Charger

Before you shop for a marine battery charger, you should think first about how you plan to use it:

• Starting boat battery charger: This type of marine battery charger also is referred to as a “cranking boat battery charger.” It is used as a backup for charging the starting battery on your vessel (you will rely first and foremost on your engine for that).

• Trolling battery charger: Trolling motor battery chargers are used for trolling batteries. When shopping for this type of charger, make sure you pick one that is waterproof and can stand up to being knocked around. It typically will be an on-board battery charger.

• House battery charger: This type of charger is a deep cycle marine battery charger. It usually will have an inverter.

How many amps and volts do you need for your marine charger? With higher amps, you can expect more rapid charging. But there are limits based on the types of batteries you have as well as Ah. Here is a simple formula you can use to calculate that maximum:

C rate x Ah = A

So, for instance, .5C is the highest C rate suggested for lithium-ion batteries. Let’s say the battery is 100Ah. We multiply .5 x 100 to get 50A.

As for the voltage you need when you are shopping for the best marine battery charger, you will need to take a look both at the battery’s voltage and that of the supply. Also, consider whether an alternator is involved.

What features do you need in a boat battery charger?

• Voltage: You must go with a voltage that is right for your equipment. On a boat, that typically means 12 or 24 volts (1).

• Battery compatibility: Make sure you are choosing a type of charger that can work with the type of batteries you have on your boat.

• Right for your use case: Choose a marine battery charger based on your plans. For example, someone who takes their boat out every few days all year long is going to need a different charger than someone who keeps their boat in storage most of the time. 

• Permanent vs. portable: Battery chargers can be fixed onboard models or portable models. Consider a portable marine battery charger if you will be using the same unit to power other vehicles, and/or your boat is small. Otherwise, it usually makes sense to go with an onboard marine battery charger.

• Number of battery banks: To charge multiple batteries simultaneously, get a multi-bank charger. 2-3 banks are most common, but there are some models with additional banks as well.

• Safety: Picking a product that prevents overcharging and overheating is important to stay safe, especially if you plan to keep your batteries and charger connected over long periods of time in storage. Smart chargers can make the necessary adjustments on their own.

• Charging time: Look for a marine battery charger that can quickly recharge your batteries—but make sure not to exceed the maximum recommendation. You do not want to be waiting days for charging when it could be completed within hours.

• User interface: How easy is it for you to check the status of the battery and choose between different charge modes? Find a battery charger that includes a clear and straightforward user interface.

• Dimensions: Finally, do not forget to consider the physical space the battery charger will take up on your boat. Think about where and how you want to mount it, and make sure you get something that fits. Check the cable lengths while you are at it. Not all chargers have extendable cables, and if they are too short for your configuration, you will be out of luck.