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NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 2 Bank - 12V - 20 Amp

NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 2 Bank - 12V - 20 Amp

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Submersible, on-board smart charger draws power from a wall outlet to charge and maintain up to (2) 12V batteries at 10-amps. Fully-sealed, waterproof construction is ideal for marine applications. Saltwater tested and ignition protected for safety. Call 800-298-8924 to order NOCO battery charger part number 329-GEN2 or order online at etrailer.com. Free expert support on all NOCO products. Guaranteed Lowest Price and Fastest Shipping for NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 2 Bank - 12V - 20 Amp. Battery Charger reviews from real customers.
  • All Info
  • Reviews (2)
  • Q & A (11)
  • Photos
  • Why etrailer?

NOCO Battery Charger

  • Boat
  • Trolling Motor
  • Generator
  • Electric Vehicle
  • Industrial Equipment
  • Battery Charger
  • NOCO
  • 12V
  • Wall Outlet to Vehicle Battery
  • Charges Only
  • 230 Ah

Submersible, on-board smart charger draws power from a wall outlet to charge and maintain up to (2) 12V batteries at 10-amps. Fully-sealed, waterproof construction is ideal for marine applications. Saltwater tested and ignition protected for safety.


  • On-board AC-to-DC smart charger quickly charges and maintains up to 2 batteries
    • Perfect for boats, trolling motors, generators, electric vehicles, and industrial equipment
  • 2 Battery banks allow multiple 12V batteries to be charged simultaneously
    • Provides full charge output even with low or varying AC current input
  • Multi-stage charging algorithm charges 2x faster than traditional chargers without overcharging
    • Analyzes battery condition to provide a customized charge
    • Built-in battery desulfator restores lost battery capacity
  • Heavy-duty 3/8" eyelet connectors provide maximum contact with terminals
    • Built-in 15-amp fuses protect electronics from dangerous overloads
  • Completely sealed, waterproof design is fully submersible - perfect for marine applications
    • Tested to resist saltwater corrosion
  • Meets USCG-33 CFR 183.410 requirements for ignition protection
  • AC port plug (sold separately) creates a connection point for easy access to AC power


  • Application: 12-volt lead-acid batteries rated up to 230 amp-hours
  • Battery types supported: wet cell, gel cell, AGM, enhanced flooded, and maintenance-free batteries
  • Number of battery banks: 2
  • Maximum charging amperage: 20 amps
    • 10 amps per battery bank
  • Eyelet cord length: 75-1/2"
  • AC cord length: 72"
  • Working voltage: 70 - 130 VAC (50 - 60 Hz)
  • IP rating: 68
  • Dimensions: 8-5/16" long x 7-1/2" wide x 3-1/8" thick
  • Weight: 8.7 lbs
  • 5-Year limited warranty

NOCO GEN2 On-Board Marine Battery Charger Diagram

The rugged NOCO Genius GEN2 on-board smart charger quickly charges and maintains up to (2) 12-volt lead-acid batteries, simultaneously. Multiple battery banks efficiently charge deep cycle and starter batteries up to 230 amp-hours. It's great for boats, trolling motors, generators, and a wide range of electric vehicles and industrial equipment. With a fully submersible design, the GEN2 was built to handle harsh marine environments, while keeping your batteries in peak condition.

Multi-Stage Smart Charging Technology

The NOCO GEN2 smart charger uses an 8-stage charging cycle to quickly and efficiently charge your battery. This ensures that the battery safely reaches maximum capacity without being overcharged.

NOCO GEN2 Genius Battery Charger Advanced Smart Charging Technology

In the first step of the charging process, the charger will analyze the battery's condition and state of charge. The charger then uses this data to diagnose the battery's health and ensure it can be safely charged. If the battery is deeply discharged or sulfated, the charger will automatically enter the recovery stage to repair the battery by pulsing small amounts of current.

Once the unit has determined that the battery's condition is stable, it will initialize the charging process by providing a constant, gentle charge. The charger gradually increases the charge during the bulk stage and quickly charges the battery to 80-percent capacity.

As the battery nears full charge, the GEN2 enters the absorption stage and delivers small amounts of current to limit battery gassing and safely bring the battery to 90-percent capacity. The charger will then begin optimization of the battery, bringing it to full capacity and optimizing it for increased run time and performance.

The final step of the charging process, maintenance, monitors the battery for drops in power and supplies the correct current to keep it fully charged. If a drop in voltage is detected, the charger will begin the optimization cycle to keep the battery fully charged.

Heavy-Duty Eyelet Connectors

NOCO GEN2 Heavy-Duty Eyelets

2 Sets of 3/8" eyelets connect the GEN2 to your batteries. Over-molded connection points stand up to heavy usage and keep connections safe from the elements. Built-in 15-amp fuses protect each connection against dangerous overcurrent.

Quickly Charge and Maintain Batteries from 120VAC Power Source

NOCO GEN2 AC Plug for Wall Outlet Charging

The GEN2 plugs into an available wall outlet to quickly charge and maintain multiple batteries. High-frequency switch-mode technology converts AC power into safe DC power to fully charge batteries. An onboard microcomputer monitors and controls this charging process to minimize power loss and maximize efficiency. Included hardware lets you mount the unit in an enclosed compartment, garage, or workspace.

NOCO GEN2 On-board Battery Charger Charging Times Diagram

The table above provides a quick reference for how long it will take the GEN2 to charge batteries with various amp-hours.

Rugged Submersible Design

NOCO GEN2 Waterproof and Ignition Proof Design

The GEN2 was built to handle extreme marine conditions. The unit has an IP68 rating, which means it can handle being fully submerged in water, and it's protected against solid particles like dust or sand. Its ignition protected for safe and worry-free operation around marine engine compartments and fuel tank spaces. Saltwater won't cause issues either. The charger has been thoroughly tested to resist corrosion.

The housing is made from tough Lexan resin that protects the internal electronics against vibration and impacts. The unit can handle being dropped, kicked over, and just about anything else your day brings.

AC Port Plug for Plug-and-Play Charging

NOCO GEN2 GCP AC Port Accessory

Available AC port plugs (sold separately) from NOCO let you easily setup your GEN2 charger for plug-and-play charging with any extension cord. The plug creates a "pass through" AC charging port on a surface, so you can quickly connect to the charger when it's mounted inside a compartment on a truck, boat, trailer or RV. This allows you to easily access the charger for charging engine block heaters, trolling motors, batteries, and other equipment. A snap-fit cap creates a watertight seal to protect the connection whenever you're done.

GEN2 NOCO Genius On-Board Marine Smart Battery Charger - Submersible - AC to DC - 2-Bank - 20 Amp - 12V

Item # 329-GEN2

Installation Details 329-GEN2 Installation instructionsAlternate Instructions 329-GEN2 Installation instructions

California residents: click here

Customer Reviews

NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 2 Bank - 12V - 20 Amp - 329-GEN2

Average Customer Rating:  5.0 out of 5 stars   (2 Customer Reviews)

Submersible, on-board smart charger draws power from a wall outlet to charge and maintain up to (2) 12V batteries at 10-amps. Fully-sealed, waterproof construction is ideal for marine applications. Saltwater tested and ignition protected for safety.

- 329-GEN2

These NOCO products seem very good, the GEN2 will be going in a boat soon. I have a GEN4 tending 4 classic cars for over a year and have had no problems what so ever. e trailer is very easy to shop and package arrived 3 days ahead of time promised very happy with the service. thanks 809717

- 329-GEN2

This unit has performed flawlessly. Installed it in my camper. I needed a way to charge 2 batteries and with a charger set up to only charge 1, I was not getting a complete charge. The charging and maintaining ability for 2 batteries works great and for the particular battery size I have it will charge from a 50% to full state in 2 hours. 657126


Ask the Experts about this NOCO Battery Charger

  • Should Indicator Lights Illuminate When Noco Battery Charger is Connected to Batteries
    Is the charger plugged into a wall outlet? It does not draw power for the diagnostic/indicator lights from the batteries and instead does from outlet it's plugged into. If there are not lights that come on the charger when plugged into a wall that would indicate most likely an internal problem.
    view full answer...
  • Troubleshooting Alternating Red and Green LED on NOCO Genius Mini 2 Bank Charger
    The NOCO Genius Mini On-Board Battery Charger - AC to DC - 2-Bank - 12V - 8 Amp # 329-GENM2 is showing that your batteries are not being recognized by the charger. The alternating Red/Green is standby mode so since you have your batteries connected, they may be depleted lower than the charger can recognize. I reached out to my tech contact who said if they are depleted below 2 volts, you would need to use an alternate charging system to get them to that recognizable 2 volt for this system...
    view full answer...
  • How To Wire and Charge Two 12 Volt Batteries Wired In Parallel
    In regards to a parallel battery bank, the positive terminals will be joined with the last cable then ran to the distribution panel. The two negative terminals will also be joined with the last cable then ran to the trailer frame. I have attached a photo for you of this setup. The amp hour capacity will then double when wired in parallel. I cannot recommend any other variation of the above. In regards to charging, you will want to charge each battery separately in order to ensure they...
    view full answer...
  • Why Does Battery Charger Take Longer to Get to Fully Charged Green Light Status
    Sometimes it takes longer than you'd think to get to the totally full charge status using a charger like the NOCO Genius Mini part # 329-GEN2. That last little bit takes time to top off as the charger goes down into a lighter charge. I've had a similar experience with CTEK chargers and it took a couple of days once to get to the fully charged float status. If the battery is working though and is mostly charged you are totally fine.
    view full answer...
  • Troubleshooting NOCO Genius On-Board Battery Charger that Won't Show Green on Display
    First thing I would try is a new outlet to plug the NOCO Genius On-Board Battery Charger # 329-GEN2 into as that would be the easiest fix. Next check the fuses in each of the lead wires that run to the batteries as they may need replacing as well. If the charger still does not show any signs of life it's most likely defective and needs replacing. It has a 5 year warranty.
    view full answer...
  • How to Connect NOCO Genius 329-GEN2 2-Bank Battery Charger
    When you use a 12V battery charger like the NOCO Genius 2-Bank charger # 329-GEN2 you do need to disconnect your series-wired batteries so that each bank on the charger is connected to one 12V battery. This 12V charger will not operate correctly into a 24V load. It will do a great job of charging both batteries since each bank outputs 10-amps charging current and is compatible with battery capacities up to 230-amp hours.
    view full answer...
  • Error Lamp Flashing on NOCO Genius Battery Charger
    If it's the ERROR lamp flashing, there are several reasons why that would occur. -Battery Voltage Incompatibility. If your charger is meant for 12V batteries only, be sure you're not trying to charge a 6V battery. -Low Voltage Battery. If the battery voltage is below 2.0VDC (12V), it could cause this ERROR condition. In this situation, the battery charger has determined that the battery voltage is too low to begin a normal charge cycle. To increase the battery voltage and allow...
    view full answer...
  • Types of Battery Chargers for Auxiliary Battery on Dump Truck/Trailer
    We do offer battery chargers, including AC-powered unit like NOCO Genius # 329-GEN2 and DC-powered types like Redarc # 331-BCDC1225D, as well as Solar panel chargers like # PTW2997 that help maintain your auxiliary battery whenever sunlight is available. The vehicle wiring kits we sell are generally limited to passenger vehicles to allow them to tow recreational trailers. If you are looking for a heavy-duty wiring kit to deliver power to your dump bed motor this would best be sourced...
    view full answer...
  • How Much Battery Power Is Needed to Operate Electric Tongue Jacks
    Your specific battery's amp-hour rating (Ah), its condition and the specific jack in use will determine how many uses you will get before your battery is drained. Powered trailer tongue jacks like the Bulldog # BD500188 and the Stromberg Carlson # JET-5000, as examples from those on the linked page, can draw substantial power. The specific power drawn by the jack depends on the particular jack and the actual load that is on it. The Stromberg Carlson # JET-5000 will pull about 30-amps...
    view full answer...
  • Can NOCO Genius Mini On-Board Battery Charger be Used to Charge Deep Cycle Battery
    The NOCO Genius Mini On-Board Battery Charger # 329-GENM2 is actually designed for use both with AGM and gel cell batteries so this will work as long as it isn't over 120 amp-hours. You only need to connect one set of the terminals for this. If you do have a larger battery than that you just need part # 329-GEN2 instead which is rated for batteries up to 230 amp-hours.
    view full answer...
  • Recommended Charger for 2018 Jeep Wrangler JLU With Main and Aux Battery
    The NOCO Genius Smart Battery Charger - AC to DC - 6V/12V - 10 Amp # 329-GENIUS10 is a great option for charging your batteries. The way your batteries are connected would be good to know. If they are in true parallel this will work well. If there is a solenoid involved, then your second battery won't receive power unless the ignition is on, so if that is the case you would need to have a second bank connection for a multiple battery charger like # 329-GEN2 or a complete separate charger.
    view full answer...

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Info for this part was:

Expert Research:
Mike L
Expert Research:
Jameson C
Expert Research:
Adam R
Installed by:
Randy B
Edited by:
Daron K
Written by:
Brian T

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