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

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

Item # 329-GEN2

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NOCO Battery Charger - 329-GEN2
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Product Images


  • Battery Charger
  • NOCO
  • Wall Outlet to Vehicle Battery
  • Boat
  • Trolling Motor
  • Generator
  • Electric Vehicle
  • Industrial Equipment
  • Charges Only
  • AC to DC
  • 12V
  • 230 Ah
Submersible, on-board battery charger draws power from a wall outlet to charge and maintain up to 2 batteries. Multi-stage charging algorithm charges batteries 2x faster than most marine chargers. Rugged, waterproof design for marine applications. Call 800-298-8924 to order NOCO battery chargers part number 329-GEN2 or order online at Free expert support on all NOCO products. Guaranteed Lowest Price and Fastest Shipping for NOCO Genius On-Board Battery Charger - AC to DC - 2-Bank - 12V - 20 Amp. Battery Chargers reviews from real customers.

  • All Info
  • Reviews (1)
  • Q & A (6)
  • Videos (1)
  • Photos
  • Why etrailer?

NOCO Battery Chargers - 329-GEN2

Submersible, on-board battery charger draws power from a wall outlet to charge and maintain up to 2 batteries. Multi-stage charging algorithm charges batteries 2x faster than most marine chargers. Rugged, waterproof design for marine applications.


  • On-board AC-to-DC battery charger draws power from a wall outlet to charge and maintain up to 2 batteries
    • Ideal for starter and deep-cycle batteries rated up to 230 amp-hours
    • Perfect for boats, trolling motors, generators, electric vehicles, and industrial equipment
  • 2 Battery banks allow (2) 12-volt batteries to be charged simultaneously
    • Provides full charge output even with low or varying AC current input
  • Multi-stage charging algorithm charges batteries 2x faster than traditional chargers without overcharging
    • Analyzes battery condition and customizes charge to quickly and fully charge battery, providing a maintenance charge when needed
    • Built-in battery desulfator restores lost battery capacity
  • Firewall protects internal electronics against short circuits, open circuits, overheating, overcurrent, and reverse polarity
  • Over-molded connection points protect cables from damage and provide a water-resistant seal
  • Completely sealed and waterproof design is fully submersible - perfect for on-board marine applications
    • IP68 rated for protection against shock, vibration, water, dirt, and dust
    • Saltwater-tested to combat corrosion
  • Integrated eyelet connectors and Type-B AC power cord included
    • AC Port Plug (329-GCP1 - sold separately) makes it easier to access a charging port while maintaining a waterproof seal
  • Meets USCG-33 CFR 183.410 requirements


  • Application: 12V batteries
    • Battery types supported: wet cell, gel cell, AGM, enhanced flooded, and maintenance-free batteries
  • Charger dimensions: 8-5/16" long x 7-1/2" wide x 3-1/8" thick
  • HD eyelet cord length: 75-1/2"
  • AC cord length: 72"
  • Battery capacity range: 25 to 230 amp-hours
  • Input voltage: 70 - 130 VAC (50 - 60 Hz)
  • Number of battery banks: 2
  • Maximum charging amperage: 20 amps
    • 10 amps per battery bank
  • Output voltage: 12V DC
  • Weight: 8.7 lbs
  • Limited 5-year warranty

NOCO GEN2 On-Board Marine Battery Charger Diagram

Advanced Battery Charging Technology Reduces Charging Times

NOCO GEN2 On-board Battery Charger Charging Times Diagram

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

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Video of NOCO Genius On-Board Battery Charger - AC to DC - 2-Bank - 12V - 20 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-GEN2 Review

Speaker 1: Today we're taking a look at the NOCO Genius Gen 3 Onboard Dual Bank 12 Volt battery charger. This charger works to charge two 12 volt marine starting or deep cycle batteries. It's gonna mount directly to your boat generator or other equipment with the battery.You see we've got holes here and here. It allows you to mount it to any flat surface. Now it's suited for batteries rated up to 230 amp hours. It can also be used to maintain batteries.

So if they're already fully charged, we can use this in place and just make sure that they hold that charge.Now it's designed for charging 12 volt led acid batteries. Those include the wet cell, gel cell, enhanced calcium, maintenance free, and AGM batteries. It's water proof, crush, shock, and vibration resistant. And the very rugged design is very submersible and it's been salt water tested to make sure it combats corrosion properly.It has built in battery maintenance technology. That's gonna monitor the battery, and it begins charging it when it's needed.

This allows for continuous operation with zero risk of overcharging. It's efficiently converting AC wall power into DC power that's battery safe. It converts the power many times faster than a traditional automotive battery charger will.For additional safety it also offers ignition protection that gives a safe and worry free operation. To connect it to your battery you're gonna use the heavy duty ring terminals here. I like the design.

They're flat spotted on the bottom. This allows them to mount right down flush on top of the battery. On the positive side here you'll notice got a fuse holder. I like the way the fuse holder's designed. It's heavy duty.

Inside we're gonna have our 15 amp ATC style fuse, so that protects both what we're charging and our charger from any kind of short and if that goes out it's easily replaceable.Now the charger does have built in LEDs. The one is gonna be for charge status. When it's charging it'll be red, when the battery's full of charge it's gonna be green. And we've got that for both banks. Also for both banks we have our safety light, or indication light here is we have some kind of problem, whether that might be a reverse polarity situation or any other thing that might need to be addressed.Now it also has a built in battery desulfator. This works really, really well at rejuvenating underperforming batteries. And this system can also recover a deeply discharged battery, even if it's down to two volts.Now the leads that go to our batter are gonna be 72 inches long. They're constructed of 16 gauge wire. That gives you good reach from your mounting location to get over to where your batteries might be.The AC plug side, this is gonna be 75 and a half inches long. It's 18 gauge wire, so that should allow you to get to a plug, but this is also gonna work out very well with the NOCO Genius AP port plug. I'm sorry AC port plug with the extension cord. That allows an external area for you to plug in your extension cord and charge everything up. Now it requires 70 to 130 volts of AC power to operate properly. That's very common in houses and shops, should be easy to find. And it delivers a total of 20 amps charging output. That's gonna be 10 amps per bank. It has an IEP rating of 68 and it's gonna meet the US Coast Guard- 33CFR183-40 requirement. That's gonna complete our look at the NOCO Genius Gen 2 Onboard 12 Volt Dual Bank battery charger.

Customer Reviews

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

Average Customer Rating:  5.0 out of 5 stars   (1 Customer Reviews)

Submersible, on-board battery charger draws power from a wall outlet to charge and maintain up to 2 batteries. Multi-stage charging algorithm charges batteries 2x faster than most marine chargers. Rugged, waterproof design for marine applications.

- 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 Chargers

Do you have a question about this Battery Charger?

  • 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-4000NG, 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-4000NG will pull about 13.5-amps...
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  • 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...
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  • 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.
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  • 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...
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  • 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.
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  • 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.
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Info for this part was:

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

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