1. Battery Charger
  2. NOCO
  3. Battery Charger
  4. Boat
  5. Trolling Motor
  6. Generator
  7. Electric Vehicle
  8. Industrial Equipment
NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 30 Amp

NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 30 Amp

Item # 329-GEN3
lowest price pledge
Our Price: $279.97
You Save: $94.98
Battery Charger
This item qualifies for Free Shipping
Shipping Weight: 17 lbs
In Stock
zoom in icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images


Submersible, on-board smart charger draws power from a wall outlet to charge and maintain up to (3) 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-GEN3 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 - 3 Bank - 12V - 30 Amp. Battery Charger reviews from real customers.
  • All Info
  • Reviews (2)
  • Q & A (3)
  • Videos (1)
  • Photos
  • Why etrailer?

NOCO Battery Charger - 329-GEN3

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

Submersible, on-board smart charger draws power from a wall outlet to charge and maintain up to (3) 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 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 230 amp-hours
  • Battery types supported: wet cell, gel cell, AGM, enhanced flooded, and maintenance-free batteries
  • Number of battery banks: 3
  • Maximum charging amperage: 30 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: 11-3/8" long x 9-1/2" wide x 3-1/8" thick
  • Weight: 15.1 lbs
  • 5-Year limited warranty

NOCO GEN3 On-Board Marine Battery Charger Diagram

The rugged NOCO Genius GEN3 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 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 GEN3 was built to handle harsh marine environments, while keeping your batteries in peak condition.

Multi-Stage Smart Charging Technology

The NOCO GEN3 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 GEN3 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 GEN3 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 GEN3 Heavy-Duty Eyelets

3 Sets of 3/8" eyelets connect the GEN3 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 GEN3 AC Plug for Wall Outlet Charging

The GEN3 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 GEN3 On-board Battery Charger Charging Times Diagram

The table above provides a quick reference for how long it will take the GEN3 to charge batteries with various amp-hours.

Rugged Submersible Design

NOCO GEN3 Waterproof and Ignition Proof Design

The GEN3 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 GEN3 GCP AC Port Accessory

Available AC port plugs (sold separately) from NOCO let you easily setup your GEN3 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.

GEN3 NOCO Genius On-Board Marine Smart Battery Charger - Submersible - AC to DC - 3-Bank - 30 Amp - 12V

Installation Details 329-GEN3 Installation instructionsAlternate Instructions 329-GEN3 Installation instructions

California residents: click here

Video of NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 30 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-GEN3 Review

Speaker 1: Today we're taking a look at the NOCO Genius onboard battery charger. The on board battery charger is designed for charging and maintaining three 12-volt marine, starter, or deep cycle batteries. It mounts directly to your boat, trolling motor, generator, electric vehicle, or industrial equipment. It has three banks on it so you can charge up to three batteries at the same time, and it's ideal for batteries up to 230 amp hours. It simply converts your AC power into safe DC power for battery charging. Charging amperage is 30 amps.

That's 10 amps per bank. It has a lot of built-in smart technology, so this unit's designed to monitor battery activity for safe, fast, and efficient charging of lead acid batteries such as wet, gel, AGM, EFB, and maintenance free batteries without the worry of overcharging. It begins charging when needed, and it also allows for continuous operation without supervision.It's also 100% sealed for a waterproof and fully submersible design, and it's saltwater tested to combat corrosion. Right here we have the charge LEDs. These LEDs allow you to visually see the charging status of each bank or of each battery.

They'll light up red when charging and then they'll turn to green when charging is complete. Also you have an exclamation point surrounded by yellow. That's gonna be the error notification, so you also have an error LED on each bank that notifies you when error conditions are present or when error conditions exist. The unit also features a built-in battery desulfator, which is designed to rejuvenate underperforming batteries. Simply what that does is it's a system that's built in here that allows the unit to recover deeply discharged or worn-out batteries.

This is a really nice unit.A few other features that it contains is that it features spark-proof technology as well as reverse polarity protection. When it comes to that waterproof design, it's an IP68 rated unit. It's also ignition protected, so this is a non-igniting and temperature controlled onboard battery charger that allows for safe and worry-free operation. So again, you'll notice it's a nice design, black in color, very solid unit. You have three banks, you have your wiring, black for negative, red for positive posts.

That has the lay flat connection points on it, and these are designed to fit over 3/8 inch diameter posts, and then each bank is protected with an in-line fuse, 15 amp fuse. It does come with insulation hardware, so if you wanna install it as the preformed holes right here in the casing, so that way you can easily get it mounted.Power cord, three-prong protector. There's the underside of the unit, nice flat design. Does have some feet on it, so it does keep it a little bit elevated. A few measurements I wanna go over with you real quick. I took a measurement of the unit from outer edge to outer edge going this direction, and when I did that I got a measurement of 11 1/2 inches long. I also took a measurement of the overall width, so just at the base, outer edge to outer edge, you got a measurement of 8 3/8 inches wide, and then from bottom to top in this orientation, that measured about 3 1/8 inches tall or deep. The mount holes on the unit, there's four of them, one on each corner. The corner ones are separated on center going this direction apart from one another by 6 7/8 inches, and then from this one to this one and this one to this one, so length-wise, they're separated on center by 9 5/8 inches.That's gonna do it for today's look at the NOCO Genius 3 onboard battery charger.

Customer Reviews

NOCO Genius On-Board Battery Charger - AC to DC - Waterproof - 3 Bank - 12V - 30 Amp - 329-GEN3

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 (3) 12V batteries at 10-amps. Fully-sealed, waterproof construction is ideal for marine applications. Saltwater tested and ignition protected for safety.

- 329-GEN3

I have had no issue with the charger. It works like it is designed and I am totally satisfied. 809319

- 329-GEN3

My previous charger died and took the entire battery bank with it. The Noco Genius was easy to install and plug in to a regular 110 socket so no splicing electrical hard wires. The cord was a little short so I mounted it on the genset sound shield then threaded the power cord through the top of the back bulkhead to the power source. Easy to see status lights, absolutely automatic sensing so it will not cook your batteries. I love it! 644346


Ask the Experts about this NOCO Battery Charger

  • Best Way To Charge Six 6 Volt Batteries
    In order to charge your battery bank I highly recommend using the NOCO Genius On-Board Battery Charger part # 329-GEN3. This charger will change all of your batteries at one time but you will need to hook up each bank to each of the three series. The issue you will run into with trying to charge all six batteries with one bank is that the charger would need to be rated very high in order to handle the amp hour capacity which we do not offer nor do I think you would like the price if you...
    view full answer...
  • Is the 25-230 Ah Capacity of the NOCO Genius for Reverse or Cranking Amps
    The battery capacity range of the NOCO Genius On-Board Battery Charger part # 329-GEN3 is 25-230 Ah which refers to the reserve capacity, not the cranking amps. This is the highest three bank model we offer but there is one below this, the NOCO Genius Mini On-Board Battery Charger part # 329-GENM3 which has a battery reserve capacity range of 25-120 Ah.
    view full answer...
  • What Battery Amp Hour Rating is the NOCO Genius On-Board Battery Charger # 329-GEN3 Designed For
    The NOCO Genius On-Board Battery Charger # 329-GEN3 was intended for use on batteries that are up to 230 aH. If you were a bit higher than that with your battery this would still do a decent job charging it, but if you were significanly higher it would not work.
    view full answer...

Do you have a question about this Battery Charger?

  • Why etrailer.com?

    At etrailer.com we guarantee:
  • Highest quality battery charger for the best price.

    Our Lowest Price Pledge ensures you will never overpay for the parts you need.
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate battery charger information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Expert Research:
Jameson C
Installed by:
Cole B
Edited by:
Daron K
Written by:
Brian T

At etrailer.com we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.