You never want your battery to die while you’re out on the water. A good boat battery charger can go a long way to making sure you’re never stranded. The question you’re probably asking is how to find the charger that will work right with your battery – and how to get it at the best value.
If these are your questions, you’ve come to the right place! Read on to learn about the ten best boat battery chargers on the market and see advice on how to pick one. Anyone looking for portable power will find what they’re looking for below.
Top 3 Best Boat Battery Charger Comparison Chart
BMK 12V Portable Smart Boat Battery Charger/Maintainer
Noco Genius GENM2 Smart On-Board Boat Battery Charger
ProMariner 43012 ProSport Boat Battery Charger
|Dimensions||9.5” X 4.6” X 2.9”||7.9” X 2.2” X 5.5”||9” X 6.5” X 12”|
Boat Battery Charger Buying Guide
One reason it can be tricky to shop for a boat battery charger is that there’s no one size fits all solution that will work for every battery. It all depends on the size and style of your battery and how you use it.
So how do you pick the best boat battery charger for you? Let’s look at some of the key factors and give you the knowledge you need to make the right decision.
What is a boat battery charger?
A marine battery charger or boat battery charger operates in the same basic way as other types of battery chargers. They connect to the terminals of your battery to either restore or maintain the charge. This is typically done when the battery is not in use, though some boat battery chargers can be left attached to the battery full-time.
Boat battery chargers come in different styles, including:
- Trickle chargers. Trickle chargers deliver only a small amount of charge. This means you can leave them plugged onto a battery without concern of overcharging. The downside is they’ll take a long time to restore a battery’s full charge if it’s depleted.
- Quick chargers. Also called “boost chargers”, these models deliver a high charge to refill a depleted battery more quickly. Overcharging is the main concern, and you’ll want to monitor the battery and remove it from the charger as soon as it’s full.
- Battery tender. Similar to trickle chargers, battery tenders or battery maintainers deliver a relatively low amount of charge. The main difference is battery tenders use electronic circuitry to determine the charge level of the battery and only send power when it’s needed. Because of this, they’re the safest option for maintaining a boat battery’s charge in the off-season.
- Smart chargers. The most sophisticated of the chargers, smart chargers have multiple modes that it switches between automatically based on what the battery needs. Many chargers of this design also include recovery modes that can restore the plates inside the battery after deep depletions.
Why should you get a boat battery charger?
- They’re designed for marine use. While you technically could use an automotive charger on a boat battery, it’s not the best choice. Marine batteries have unique needs, including the shape of the terminals, the conditions they’re used in, and the ideal rate of charge. Boat battery chargers are built to meet these needs safely.
- Maintain the charge of the battery in storage. All batteries lose a certain amount of their charge over time, a process that’s known as “self-discharge”. Keeping the battery on a trickle charger or maintainer when it’s not in use will prevent this power loss. That extends the useful lifespan of the battery and makes sure it’s ready to go when you need it.
- Prevent problems on the water. About 10% of distress calls sent by boaters are because of electrical issues, many caused by dead batteries. Keeping a boat battery charger on-hand can help avoid battery issues before they leave you stranded.
What do you expect out of the boat battery charger?
Now that you know what a boat battery charger is and why you need one, how do you choose the right one? Let’s take a look at the main features and stats to pay attention to when you’re shopping.
Voltage and output: Do you need the best performance?
There are two key numbers you’ll see on any boat charger: the voltage and the output. While these are both terms related to energy, they indicate different things about the charger.
A charger’s voltage tells you what size of battery it’s designed to work with. Like automotive batteries, most boat batteries are 12 volts, though you will also find smaller 6-volt options and larger 24-volt batteries in use.
The voltage of the charger should exactly match the voltage of your battery. Charging a 6-volt battery with a 12-volt charger will likely damage the battery. If you go the other way, the charger won’t generate sufficient charge to refill the battery.
Output, on the other hand, is measured in amps, and tells you how much power the charger sends to the battery. The higher the amp rating, the faster your battery will charge. A higher amp rating is also helpful for charging large batteries or deeply-depleted batteries.
While you don’t need to match this number to your battery, you’ll generally want a higher output for a larger battery and a lower output for a smaller one. A good rule of thumb is to charge at a rate equal to 20-40% of the battery’s total amp hour capacity. Higher than that and you risk overcharging; lower, and the charge will take a long time.
Desulfation and Recovery
The plates inside a battery naturally break down over time, a process known as sulfation. High heat and deep discharges can accelerate this process. Many smart chargers include a program that can un-do this damage, known as desulfation.
With a recovery program, you can extend the maximum lifespan of your battery, sometimes even bringing a dead battery back to full health. This can be a big money-saver compared to just replacing batteries that have taken this kind of damage.
Number of Banks
The number of banks on a charger tells you how many batteries it can charge at once. If your boat uses two batteries, or if you’re maintaining batteries for multiple watercraft, a 2- or 3-bank charger is a helpful option. You’ll be able to easily maintain all your batteries with one device instead of switching the charger between the batteries periodically.
Anything you use on a boat is going to be close to water, a natural enemy of electronics. Boat battery chargers with waterproofed casings will prevent damage from the elements. They’re also safer, preventing sparks and current from flowing where it isn’t supposed to.
If you’ll only be charging batteries at your dock or garage, portability may not be much of a concern. For those who plan to take the charger out on the water with them, a more compact, lighter-weight option can be much more convenient. This allows you to transport it from place to place without a hassle.
Best boat battery charger review
1. BMK 12V 5A Portable Smart Boat Battery Charger/Maintainer
We’ll start off with this remarkably portable battery charger from BMK. It’s the perfect charger for batteries of small recreational boats. It has the power to keep you on the water longer for a reasonable price, in a very compact package.
The casing of this BMK charger is completely waterproof. It’s made of a high-quality plastic that resists damage from impacts or vibrations without carrying a charge. Along with interior protection against sparks and surges, that makes it a very safe choice.
It’s easy to hook up this charger to any battery. It includes both alligator clamps for quick charges and rings for permanent installation. This convenience and usability are what caught our attention and earned its spot on this list.
- Fully-automatic 4-stage charging.
- Most portable option.
- Multiple connection options included.
- Waterproof plastic casing.
- Recovers and desulphates dead batteries.
- Plug and play operation.
- Included rings might not fit all posts.
- Gets quite hot during the charging phase
2. NOCO Genius GENM2 8 Amp 2-Bank Waterproof Smart On-Board Boat Battery Charger
If you want to charge your batteries in a hurry, the Genius line from Noco is your answer. This onboard boat battery charger has an all-plastic casing that’s safe and easy to install on any boat. Best of all, the dual charging banks let you use it for both your starting and trolling battery.
Noco’s Rapid Charge technology is impressively fast – twice as fast as most chargers. That’s not the only smart thing about this charger, either. Its advanced reconditioning system repairs dead and damaged batteries.
Chargers from Noco don’t come cheap. If you want the fastest charge possible, though, it’s worth the price. The advanced repair function can be a life-saver, too.
- Fully waterproofed
- Organic battery feedback adjusts the charge to the battery’s needs
- Charges twice as fast as comparable models
- Plastic casing makes it safe for all boats
- Advanced recovery mode to recondition dead batteries
- Dual banks for charging two batteries at once
- Price is on the high side
- A bit heavy
- Ring terminals aren’t convenient for quick applications
3. ProMariner 43012 ProSport 12 12Amp 12/24 Volt, 2 Bank Generation 3 Battery Charger for Boat
For over three decades, Professional Mariner has devoted themselves to producing high-quality marine equipment. Their on-board fully-automatic marine battery charger is the top of the line for speed and efficiency. The dual charging banks are helpful, too, especially for seasonal storage.
This charger will work with both 12v and 24v batteries. It’s very efficient, too, and offers automatic reconditioning features that can improve your battery’s lifespan.
The price of this charger is reasonable considering what you get. Having said that, it is on the pricey side, especially for a hobbyist. For serious boaters, though, the extra expense is worth it for the dual charging banks alone.
- Energy saver mode increases operational efficiency
- 2-bank design charges two batteries at once
- Charges both 12v and 24v batteries
- Automatically gives you feedback on your battery
- Design is 40% lighter than previous generations
- Reconditions batteries while in storage.
- Most expensive option
- Doesn’t mount easily in all boats
4. ProMariner Multi 43008 8 Amp Battery Charger for Boat
Here’s another great choice from ProMariner that gives you a lot of versatility and power in a portable package. In our opinion, this is the best boat battery charger for long-term on-board maintenance. While it’s not the cheapest option out there, the performance is worth the price.
You can use this charger for stored batteries, too. In that regard, the Recondition Mode is probably the most impressive thing about this charger. It gives stored batteries a monthly reconditioning so you can count on them when you need them.
Versatility and reliability are the strong points here. It’ll work just as well for you on the boat as for off-season storage, and in the convenience of one portable unit.
- Automatically maintains batteries in Energy Saver Mode
- Recondition Mode maximizes battery life
- Lightweight and portable design
- Works with both 12 and 24-volt batteries
- Easy to install and use
- More expensive option
- The metal casing can be a safety risk in metal boats
5. MOTOPOWER MP00205A 12V 800mA Fully Automatic Boat Battery Charger/Maintainer
If your budget’s tight, you’ll love this little charger from MotoPower. It gives you the performance you need for charging and maintaining a boat battery for less than $15. That’s an incredible value whichever way you cut it.
Now there is a caveat to this. In terms of power, this has the lowest on the list. It’s rated at 800mA, which is less than an amp. That’s fine for maintaining a battery but it’ll be very slow charging. It also won’t restore batteries that are deeply discharged.
Most people don’t need a huge amount of power for maintaining a battery, though. If you’re looking for a cheap option to keep a fresh battery in good shape, this charger will serve you well.
- Most affordable option on the list
- Comes with the option of rings or clamps
- Smart charging program maintains battery automatically
- Weighs less than a power
- Durable plastic casing
- Zero-draw current with a low power consumption
- Lowest amp rating on the list
- Won’t restore deeply discharged batteries
- Slow charging
6. Minn Kota On-Board Alternator Boat Battery Charger
If you’re looking for a rugged, no fuss portable battery charger, this Minn Kota on-board charger fits the bill. It works on any style battery up to 12V and is portable enough for on-board use. The all-plastic casing is waterproof, too, so you can use it on the water without a worry.
The no-frills design of this charger has its good and bad points. On the plus side, it’s virtually indestructible and super easy to use. The negative is it doesn’t give you much information about the battery’s status.
You won’t want this charger if you need to recondition or restore a battery. For regular maintenance and daily use, though, this Minn Kota charger is both durable and efficient.
- The casing is all-plastic and waterproof
- Easy to install and use
- Very compact
- Automatic shutoff protects from over-charges
- Resists damage from vibration, corrosion, or shocks
- The interface is very basic and doesn’t give much information
- No reconditioning functions
7. TPE 24V 5Amp Smart Automatic Portable Boat Battery Charger/Maintainer
Chargers for large batteries can be expensive. If you need to charge a 24v on a budget, look no further than this Smart Automatic charger. It gives you massive power for less than fifty bucks, and without losing anything on the quality front, either.
This unit has built-in safety features to protect against over-charges and short circuits. The only thing we’re wary of from a safety perspective is the metal casing. If you have a metal boat, you’ll need to insulate the charger to prevent transferring the charge.
That small issue aside, this is a fantastic charge for both water and land vehicles. This versatility makes it an even better value. At just over a pound, it’s also very compact and portable.
- Redundant built-in safety features
- A most affordable option for 24-volt batteries
- Great for marine and land applications
- High input current for consistent, fast charge
- Compact, lightweight construction
- Metal construction might not be safe for metal boats
- The interface doesn’t give much information about the charge
8. BLACK+DECKER BM3B Fully Automatic 6V/12V Boat Battery Charger/Maintainer
Black+Decker is a boat battery name you can trust. In this case, they’ve also brought you a charger that’s an exceptional value. With an option for either 6- or 12-volt batteries, the BM3B is a versatile and affordable way to maintain all your vehicles.
This portable, lightweight charger has built-in mounting brackets to make installation easy. It’s simple to switch from clamps to rings or to hook them up to a battery. The multiple layers of safety features make it safe for anyone to use, too.
If you want to take all the guesswork out of charging, a smart charger is the answer. This is one of the cheapest and most dependable smart battery chargers you’ll find.
- Great value
- Charges both 6v and 12v batteries
- Easy to connect to any battery
- Well-built with adequate safety protections
- Built-in mounting bracket
- Will take a while to charge deeply discharged batteries
- Difficult to tell when batteries are fully-charged
9. Battery Tender (022-0186G-DL-WH) 12V 5 Amp Boat Battery Charger
This 5-amp smart battery charger from Battery Tender is a great choice if you want a maintainer you don’t have to think about. The 4-stage smart charging system automatically senses how much current your battery needs. In addition, built-in protections prevent over-charging and power surge damage.
The size of this Battery Tender model makes it truly portable. It weighs just under 2 pounds and will fit easily into any boat engine set-up. It’s built to last, too, with redundant protections against short circuits and over-charges.
- Extremely lightweight and portable
- Casing is water-resistant
- The fully-automatic 4-step charging system
- Relatively high output for a fast charge
- Doesn’t diminish capacity over time like trickle chargers
- Can take a while to charge deeply discharged batteries
- Cords can’t be switched out for longer versions
10. LST 12V Battery Trickle Charger Maintainer Portable Smart Float Charger for Boat
Finally, we have another option for the budget-minded consumer. This LST model is the most affordable deep cycle battery charger you’ll find. While it’s not the fastest charger out there, it will maintain your battery anywhere, in any conditions.
The design of this charger is impressive. It’s not only very lightweight but also completely waterproof. The all-plastic casing means you can mount it on any boat without concern.
If you want fast charging, you may need to look elsewhere. For regular maintenance, though, this is arguably the best boat charger for the money.
- Very affordable
- Includes both rings and clamps
- Compact and portable
- Fully waterproof
- 6 layers of circuit protection
- Low amp rating
- Attached cord is a bit short (under 4 feet)
The Bottom Line
The right boat charger depends on what kind of battery you have and how you plan to use it. While there’s no one right answer, if we were pressed to pick a favorite, we’d have to go with the ProMariner ProSport 12. With two banks and 12 amps of power, it’ll charge or maintain any battery.
Still need some help figuring out which boat battery charger is right for you? There are a few different ways to make your choice, but it all comes down to what your battery needs. The buying guide below will guide you through what questions to ask.
In conclusion, there are many kinds of boat battery chargers on the market. However, to make it easier for you who are looking for portable, good quality and affordable power; 10 Best Boat Battery Chargers chosen above are the best choices.
Every boat battery chargers in this list works to provide a safe choice. Hence, it’s a good solution for anyone wanting a reasonable alternative as well as reliable boat battery chargers on the market.