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NOCO Genius Mini On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 12 Amp

NOCO Genius Mini On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 12 Amp

Item # 329-GENM3
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Battery Charger
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329-GENM3 - Wall Outlet to Vehicle Battery NOCO Battery Charger
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Submersible, mini on-board charger draws power from a wall outlet to charge and maintain up to (3) 12V batteries at 4-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-GENM3 or order online at etrailer.com. Free expert support on all NOCO products. Guaranteed Lowest Price and Fastest Shipping for NOCO Genius Mini On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 12 Amp. Battery Charger reviews from real customers.
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NOCO Battery Charger - 329-GENM3

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

Submersible, mini on-board charger draws power from a wall outlet to charge and maintain up to (3) 12V batteries at 4-amps. Fully-sealed, waterproof construction is ideal for marine applications. Saltwater tested and ignition protected for safety.


  • Mini on-board AC-to-DC smart charger quickly charges and maintains up to 3 batteries
    • Perfect for boats, trolling motors, generators, electric vehicles, and industrial equipment
  • 3 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 120 amp-hours
  • Battery types supported: wet cell, gel cell, AGM, enhanced flooded, and maintenance-free batteries
  • Number of battery banks: 3
  • Maximum charging amperage: 12 amps
    • 4 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: 8-15/16" long x 8" wide x 2-5/8" thick
  • Weight: 8.6 lbs
  • 5-Year limited warranty

NOCO GENM3 Mini On-Board Marine Battery Charger Diagram

The rugged NOCO Genius GENM3 mini on-board smart charger quickly charges and maintains up to (3) 12-volt lead-acid batteries, simultaneously. Multiple battery banks efficiently charge deep cycle and starter batteries up to 120 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 GENM3 was built to handle harsh marine environments, while keeping your batteries in peak condition.

Multi-Stage Smart Charging Technology

The NOCO GENM3 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 GENM3 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 GENM3 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 GENM3 Heavy-Duty Eyelets

3 Sets of 3/8" eyelets connect the GENM3 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 GENM3 AC Plug for Wall Outlet Charging

The GENM3 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.

Rugged Submersible Design

NOCO GENM3 Waterproof and Ignition Proof Design

The GENM3 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 GENM3 GCP AC Port Accessory

Available AC port plugs (sold separately) from NOCO let you easily setup your GENM3 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.

GENM3 NOCO Genius Mini On-Board Marine Smart Battery Charger - Submersible - AC to DC - 3-Bank - 12V - 12 Amp

Installation Details 329-GENM3 Installation instructionsAlternate Instructions 329-GENM3 Installation instructions

California residents: click here

Video of NOCO Genius Mini On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 12 Amp

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.

Video Transcript for NOCO Battery Chargers - Battery Charger - 329-GENM3 Review

Speaker 1: Today we're going to be taking a look at the Noco Genius Mini On-Board 12 volt battery charger. This is designed for three bank operation, delivering 12 amps of power. This on-board charger helps to keep a charge in your triple setup 12-volt marine starter or deep cycle batteries. It's going to mount directly to your boat, generator or other equipment that has the battery you're looking to charge, and it's suited for charging batteries rated up to 120 amp hours. This can also be used to maintain a full charge on your car, RV or other larger deep cycle batteries. It's designed for charging 12-volt lead acid, wet cell, gel cell, enhanced flooded, calcium, maintenance free and AGM batteries.

It's also going to be waterproof, crush, shock and vibration resistant. The rugged design is submersible and it has been salt water tested to ensure it combats corrosion, even in those harsh environments.Now, this is a pretty advanced charger. It has built in maintenance technology. It's going to monitor the battery activity and it's going to begin charging when needed. That allows for continuous operation without supervision and zero risk of overcharging your battery.

It's designed to efficiently convert your AC or your wall power into DC power that we need to charge our battery, and it has a high efficiency platform that's going to convert that energy many times faster than a traditional automotive battery charger. For additional safety it also offers ignition protection for safe and worry-free operation.To connect to your battery, you can see we've got three sets of leads here that each one goes to an individual battery. Nice, heavy duty ring terminals there. It's flat on the bottom, it's going to sit down on your battery nicely. On each of our leads we have a heavy duty fuse holder here.

Pop that off, you'll see it's going to use a standard style, ATC 15 amp blade fuse. Nice cover, pops down over there. That's going to keep both your charger and whatever you're charging safe when you're hooking it up.It also has a built in battery desulfator. This is going to rejuvenate underperforming batteries and it recovers deeply discharged batteries all the way down to 2 volts. The DC leads are going to about 72 inches long, and they're 16 gauge wire.

The AC lead is about 75 1/2 inches long and it's 18 gauge wire. Now, this gives you a lot of options. The length of these leads are going to allow you mount this in a good location where they'll be out of the way, and the length of our plug here is going to give us plenty of reach so we can get out and plug it into what we need to.This is also compatible with the Genius AC port plug with the extension cord. That will actually give you a connection point you can mount right on the exterior of whatever item it is you want to charge, makes things a little bit easier there if you choose.Now, as far as input voltage, we need 70 volts, up to about 130 volts. That's pretty standard. It gives us a charging amperage of 12 amps, but that's going to be 4 amps per bank, for a total of 12. It has an IP rating of 68, and it meets the US Coastguard-33CFR183-410 requirement.That's going to complete our look at the Noco Genius Mini On-Board 12-volt battery charger.


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Info for this part was:

Installed by:
Randy B
Edited by:
Daron K
Written by:
Brian T

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