800-362-5397 M-F 6am-5pm PST.
MENU Menu Icon

view large photo

Swipe Photo to View More

NOCO Genius 12v 24v 36v 48v 40 Amp 4-Bank Marine On-Board Charger

Free Ground Shipping to Lower 48 States *
Out of Stock
Share this item with your friends

Product InformationStore Part Number: GEN4


The NOCO Genius GEN4 is a 4-bank 40 Amp marine waterproof smart charger and maintainer. It features four 12v 10 Amp outputs that charge individual 12v batteries that can be in series, parallel, or independent battery banks. The charger features a waterproof IP68 housing, is shock and vibration resistant, and safely monitors the batteries for fast and efficient charging.

The NOCO GEN4 is safe for Flooded, EFB, GEL, AGM, and Maintenance Free batteries. The charger safely charges and maintains batteries providing a finishing charge every 24hrs without overcharging batteries.

The GEN4 features a low voltage recovery mode that detects batteries as low as 2 volts and will attempt to recover excessively discharged or sulfated batteries. The GEN Series marine battery chargers feature reverse polarity, sparks, over-charging, overcurrent, and open-circuits and overheating protections.

The NOCO GEN4 has four 12 volts outputs meant for individual 12v batteries or battery banks that are no larger than 230AH per bank. The charger can be used to charge four 12v banks, two 24v banks using 12v batteries, one single 36v or 48v battery bank that utilizes 12v batteries.

Typical installation is for 36-volt series system using three 12v batteries for a trolling motor and an additional bank for a starting 12v battery. Another popular installation is for 24-volt series system using two 12v batteries for a trolling motor leaving two 12v banks for set of starting batteries.


  • A 4-bank, 40 Amp (12v 10-Amps per bank) battery charger.
  • Charges starter and deep-cycle batteries up to 230Ah.
  • 100% completely sealed and waterproof design rated at IP68.
  • Spark-proof technology and reverse polarity protection.
  • Provides full-charge output even with low-line voltages.
  • Recovery Mode attempts to recover deeply discharged battery as low as 2 volts.
  • Saltwater-tested to combat corrosion.
  • Safe for Wet, GEL, MF, & AGM Batteries!
  • Ignition Protection and meets USCG-33 CFR 183.410 requirements.
  • 5-Year Warranty

Tech Specs

  • Dimensions (LxWxH): 11 x 7.3 x 2.9 in
  • Weight: 12.5 lb
  • Shipping Weight: 13 lb
  • DC Output Amps: 10
  • DC Output Voltage: 12v per output
  • Output Voltage Charging: 13.5 v-14.5 v DC
  • DC Output Voltage (No Load) approx.: 0 V when battery not detected
  • Absorption Voltage: 14.4
  • AC Input Amps: 3.0
  • Maximum AC Current @ 108 VAC: 1.5
  • Maximum AC Current @ 90 VAC: 1.5
  • AC Input Volts: 120 VAC
  • AC Input Volts Freq.: 50-60 Hz
  • AC Input Volts Range: 70-130 VAC
  • Max Inrush Current, Single Cycle: 6.0
  • Float Current: 1000 mA
  • Float Voltage: 13.5 typical 24 hour re-cycle
  • Model: GEN4
  • Manufacturer: NOCO
  • Typical Efficiency: 87%
  • Power Factor: 90%
  • Power Requirements: 330 w
  • Maximum Power Output, Continuous: 190 w
  • Maximum Power (+/- 3%) @ 25° C: 360 w
  • Maximum Output Amps Single Surge: 10.5
  • Maximum Input Current: 1.5 per bank
  • Charge Reset: Battery Voltage Threshold: Below 12.8 V /timed
  • Working Temperature: 0° to 50°C
  • Storage Temperature: -20° to +60° C
  • Over Temperature: Auto overtemp foldback
  • Ripple and Noise: 50 mA at 30 kHz
  • Enclosure: Polycarbonate, sealed and potted
  • Output Banks: 4
  • Recommended Use: marine, outdoor harsh environments
  • Housing Protection: IP 68
  • Regulatory Approval: ISO8846, USCG 33CFR1830-410, FCC part 15
  • Manufacturer Part #: GEN4
  • UPC: 046221090291
  • Made In: China

Customers who bought this product also bought:

Reviews and Ratings

5.00 Average
5 Stars 4
4 Stars 0
3 Stars 0
2 Stars 0
1 Stars 0
Rated 5.00/5 Stars from 4 customer reviews.

Do you own the GEN4? Please, tell us what you think about it. It helps us provide you with better products. Please note that it may take up to 72 hours for your review to appear.

jim hoffman
Pros: Good product easy to install good teck help
Cons: no cons
your survey is to complicated needs simpler
Is this review helpful?
Written by on Jul 05, 2012. Ownership: Use regularly. Knowledge Level: AC/DC is more than a band — (90 of 167 customers found this review helpful
NOCO Genius 12v 24v 36v 48v 40 Amp On-Board 4 Bank Charger #GEN4
Pros: Great product. I use it to maintain four large batteries in an historic military vehicle. Fits nicely into the space on the vehicle available to put it.
Cons: None
Is this review helpful?
Written by on Dec 29, 2012. Ownership: Use regularly. Knowledge Level: AC/DC is more than a band — (86 of 162 customers found this review helpful
New Charger
Pros: This thing is the King Kong of battery chargers and I have had a few!! The LED lights work great inside my trailer from over 40' away. I have not had a problem with it yet!! besides being dead sexy it works like a charm and it is money well spent.
Cons: The Mounting situation is the only thing that I could complain about. It has four plastic holes that could be easily tore up. This thing does have some weight to it so keep that in mind when mounting. But dont let that put you off it is well worth it.
I purchased this thing to put in my Semi trailer it is a 53' double stacker with a 8,000 lbs liftgate. I hooked this up to an Inverter and it is charging while the truck is driving. It charges four of the big Yelleow top Optima's and works like a charm. Thanks Mike Bell Bell Transport.
Is this review helpful?
Written by on Jul 07, 2012. Ownership: I've thought about naming it.... Knowledge Level: AC/DC is more than a band — (86 of 162 customers found this review helpful
It performed great and I have worn it out and going to order a new one.
Is this review helpful?
Written by on Mar 01, 2020.

See More Reviews

Manuals & Tutorials


Data Sheet


Chargers Tutorial

Why does it read 13 volts?

Order Line: 1-800-362-5397
M–F 6am–5pm PST
Tech Help: 541-474-4421
Fax: 541-471-6014
276 Tech Way, Suite A
Grants Pass, OR 97526