You have a boat with two 12V batteries and you need a marine battery charger designed specifically for yourBoat Battery Charger NOCO Genius 2-Bank Side View situation.  You shouldn’t buy a 24V single bank battery charger and run the charge through both batteries.  One of the batteries will get more charge than the other and they will always be unbalanced.  Plus, you won’t be able to take advantage of some of the multi-step maintenance process, recovery, and desulphation functions of modern smart marine battery chargers.  What you need is a 2-bank boat battery charger connected independently to each battery that is designed to give each battery exactly what it needs and keep them both at peak charge and efficiency.  It costs more, but it will be well worth it in the long run.

You don’t just need a boat battery charger.  You also need a battery tender that will maintain the battery after it’s charged.  A 2-bank charger sporting 10 amps per bank is a reasonably fast charger, but what do you do if you need to leave your boat unused for an extended period which boat owners often do.  Some people call them a trickle charger but don’t be confused, battery tenders are smart chargers while trickle battery `chargers are typically not.




Particularly in the wintertime in certain parts of the country, boat owners store their boats to await spring when they can get out on the water again.  In the meantime, if you’re not properly maintaining your batteries, you may end up with dead batteries or even worse, bad batteries.


Want to look at other battery charger/tenders?  Be sure and see our great articles on some of the best:


The way to stop the damage and ensure your batteries are ready to crank over your motor is to hook up a smart onboard battery charger designed to maintain your battery when it’s not being used.

So don’t buy a battery charger that just brings your batteries up to charge, make sure it’s a smart charger capable of maintaining your batteries during the winter or over other extended periods when you’re not using your boat.

Boat Battery Charger NOCO Genius 2-Bank Front Kit ViewYou can save money by buying one of the battery chargers not designed for the rigors of wet conditions either on the lake or at sea.  The only trouble is, the charger will probably not last very long and you will find yourself getting a replacement probably throwing any savings out the window.

The smart buy is a fully waterproof charger sealed and designed for tough marine conditions.  This will ensure that your charger is there for you year after year when you need it.

Is the charger you’re considering mountable on your boat?  It should be.  By mounting the charger right to the bulkhead you make it much easier to use and hook up when you need to either charge or maintain the batteries.


We think we found a boat battery charger that meets all the conditions, gets great reviews and is very popular with boaters.  We searched the forums, customer reviews, retail sites, and manufacturer pages to find the perfect 2-bank charger that is rugged enough and designed to weather the tough marine environment while getting the best reviews out there.


Take a look at our pick and see if it’s the perfect marine charger for your needs!


NOCO Genius GEN2 20 Amp 2-Bank Waterproof Smart On-Board Battery Charger

Boat Battery Charger NOCO Genius 2-Bank Front ViewNOCO isn’t kidding when they call the NOCO Genius GEN2 2-Bank Waterproof Smart On-Board Battery Charger a smart charger.  The built-in microprocessor controls a fully-automatic 8-Step charging process designed to charge and maintain a variety of battery types.  You can count on this model to safely handle Wet, Gel, MF, and AGM batteries.  Its tough, fully-sealed waterproof construction, on-board mounting capability, safety features, fast charging technology, and long 3-Year limited warranty, this NOCO model has the features and capability you need at a budget price.  Here’s what you need to know.



  • Automatic 20 Amp (10 amps/bank) 2-bank, lightweight, compact, fully-sealed, waterproof (IP68), on-board, smart battery charger
  • High-frequency, high-efficiency, switch mode design makes charger more lightweight and compact than competitive models
  • Intelligent NOCO VosFX processor is fully interactive, constantly monitors input, the attached battery, and the charger itself to diagnose, recover, charge, and maintain batteries whatever the current needs
  • Handles multiple battery chemistries including Wet, Gel, MF, and AGM batteries (25-230 Ah)
  • NOCO high technology charges batteries 2X faster than traditional linear chargers and is variable input compensated producing a 100 percent full charge even with varying A/C input voltages
  • 100 percent completely sealed construction protects this model from the most extreme environments
  • Specific gravity optimization produces a stabilizing charge that optimizes the specific gravity of a battery for increased performance
  • Safety features include protection against reverse polarity, short circuit, open circuit, sparks, overheating, overcurrent, and overcharge
  • Recovery mode recovers deeply discharged and sulfated batteries using pulse charging
  • Abnormality protection automatically turns off the charger if it remains in bulk charge mode for an extended period of time
  • Mounts easily on boats, tractors, and a wide range of equipment
  • Meets ISO 8846 marine standards
  • Non-igniting and temperature controlled for safe and worry-free operation (Meets US Coast Guard 33 CFR 183.410 standards)
  • Output leads are 6-feet long and AC power cord is 5-feet long
  • Dimensions are 10.2L x 9W x 5.7H inches and it weighs 6 lbs.
  • 3-Year Limited Warranty


8-Step Intelligent Charging ProcessBoat Battery Charger NOCO Genius 2-Bank Side Kit View

  • Steps 1 & 2: Analyze & Diagnose
    • Checks the battery’s initial condition, including voltage, state-of-charge and health, to determine if the battery is stable before charging.
  • Step 3: Recovery
    • Initializes the Recovery desulphation process (if needed) for deeply discharged or sulfated batteries by pulsing small amounts of current.
  • Step 4: Initialize
    • Starts the charging process with a gentle (soft) charge.
  • Step 5: Bulk
    • Begins the Bulk charging process based on the condition of the battery and returns 80% of the battery’s capacity.
  • Step 6: Absorption
    • Brings the charge level to 90% by delivering small amounts of current to provide a safe, efficient charge. This limits battery gassing and is essential to prolonging battery life. Switches to a constant current charge rate to bring your batteries close to 90% charge.
  • Step 7: Optimization
    • Finalizes the charging process and brings the battery to maximum capacity. In this step, the charger utilizes multi-layered charging profiles to fully recapture capacity and optimize the specific gravity of the battery for increased run time and performance. The charger will switch to Maintenance if the battery tells the charger that more current is needed.
  • Step 8: Maintenance
    • Continuously monitors the battery to determine when a maintenance charge should be initiated. If the battery voltage falls below its target threshold, the charger will restart the Maintenance cycle until voltage reaches its optimal state and then discontinues the charge cycle. The cycle between Optimization and Maintenance is repeated indefinitely to keep the battery at full charge. The battery charger can be safely left connected indefinitely without the risk of overcharging.



  • High-tech smart charger
  • Easy to install
  • Great quality construction and materials
  • Safe to use over long periods






  • Short power cord
  • Leads are short
  • Poor Manual
  • Only wakes up to test battery every 24 hours


Gen Series Owner’s Manual >>>

NOCO Genius AC Port Plug w/Integrated Extension Cable GCP1

Mounts to the exterior of any vehicle to make the charging port accessible in a more convenient location. The integrated extension cable (16”) quickly plugs-n-plays with any onboard battery charger without the need of cord modifications or hand wiring. Its sleek, ultra low-profile design requires 50% less space and mounts to Boats, Golf Carts, UTVs or virtually any other electric vehicle. Rated for use at 13 Amps (13A), 125 Volts (125V) and UL Approved for US and Canada.

NOCO Genius AC Port Plug w/Integrated Extension Cable GCP1 >>>

Boat Battery Charger 



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As always, thanks for reading our post!  We sincerely hope that it has provided you with valuable information that helps you find the best boat battery charger for your needs!