GenMaax Super-High-Output Marine Alternators

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GenMaax Marine AlternatorThe GenMaax super high-output alternator is all you need to survive. It covers all the energy needs on your boat and turns your alternator into a powerful energy generator.

The GenMaax marine alternator is a totally new concept developed at our plant. These small and powerful high-performance alternators have frames manufactured in our CNC plant using 6061 aluminum.

The frames get anodized with a special salt water resistant stainless steel coating that radically enhances heat dissipation which is critical with any alternator over 160amps. The frames are manufactured in-house from billet which allows us to make the GenMaax a perfect fit on the 3.25″ and 4″ J dual foot (saddle mount), 1″ and 2″ foot mount, and pad mount engines.

Go Overboard with GenMaax

Two GenMaax alternators on one marine engine will generate 338AMPS or 4,722 watts in 12V, on a multi-hull or trawler. Four GenMaax marine alternators will generate 9,000 plus watts, eliminating the need for portable and or permanent back up generators. Hence the name GenMaax.

View the GenMaax Amperage Power Curve Chart below:

Genmaax marine alternator amperage power curve chart

Electromaax manufactures 3 mounting types as follows:

  1. GenMaax Foot Mount
  2. GenMaax J180 Mount
  3. GenMaax Saddle Mount

The GenMaax saddle mount fits these Yanmar engines:

2GM • 2GM20 • 2GM20-YUE • 2GM20F • 2GM20F-YUE • 2GMF2YM15 • 3GM • 3GM30 • 3GM30F • 3GMF • 3HM • 3HM35 • 3HM35F • 3HMF • 3JH2 • 3JH2-TE • 3JH3 • 3JH3-E • 3JH4 • 3JH4-E • 3JH5 • 3JH5-E • 3YM20 • 3YM30 • 4JH • 4JH-E • 4JH-HTE • 4JH-TE • 4JH2 • 4JH2-DTE • 4JH2-E • 4JH2-HTE • 4JH2-TE • 4JH2-UTE • 4JH3-E • 4JH3-HTE • 4JH3-TE • 4JH4 • 4JH4-AE • 4JH4-E • 4JH4-HTE • 4JH4-TE • 4JH5 • 4JH5-E • 4LHA6LY • 2QM15 • 2QM20 • 3QM30 • 3QM30F

The GenMaax currently comes in 215 Amp and 250 Amp 12V plus 165 Amp in 24V.

Benefits of GenMaax Marine Alternators vs. Generator Sets

The GenMaax was specifically developed to meet the technical demands of the new generation A.G.M, Life PO4 Lithium, Carbon Foam and Gel Batteries. Read the many benefits of installing a GenMaax on your engine if you’re considering eliminating or avoiding installing a back-up gen-set – especially when you combine its high output with solar and wind.

  • Substantially reduces weight (in a Catamaran this is very crucial)
  • Creates more space
  • Better utilization of your existing propulsion engine(s)
  • Eliminates incoming cold water and outgoing exhaust from the generator set
  • Produces continuous power output
  • Simultaneously charges your batteries and powers your on-board appliances
  • Saves tens of thousands of dollars in replacement and maintenance costs associated with gen-sets
  • Transforms your engine into a power generator
  • At idle RPM the GenMaax applies the required load to charge your batteries
  • Covers additional loads required by other devices
  • Saves capital cost more than other energy generators (solar/wind/portable generators) require
  • No additional systems to maintain
  • Dual internal fans for enhanced cooling
  • Remote rectifier to further dissipate heat and enhance performance

Applies a load at idle that prevents the engine from choking up.
The GenMaax 165 24 V super-high-output alternator produces a continuous 112 amps at 24 volts which covers most cruisers’ daily energy needs, in very short order. More significantly, it also covers very large loads simultaneously.

The simple, bolt-on replacement, 165amp, 24 volt GenMaax gives you all the output of a large-case alternator in a small case that fits 99% of Yanmar and other marine engines. It eliminates or substantially reduces a cruiser’s reliance on inboard and/or portable generators.

Remote Rectifier

For boaters with large battery banks – especially Lithium batteries – Electromaax has introduced a remote rectifier to our GenMaax alternator 250 12 V and 165 24 V models.

Electromaax marine remote rectifierRemote rectification has been in use for decades in industrial applications. With the advent of new highly advanced battery technology like LiFePO4 Lithium Carbon foam Firefly batteries, Crystal lead plus super A.G.M like now entering the marine market, these multi benefit features resolve or minimize most of the alternator issues created by these new battery types.

Removing the rectifier out of the rear part of our GenMaax 250 12 V ad the 165 24 V alternators and placing it a few feet away, has many benefits.

The major ones are listed below

By far the single biggest benefit is that over 50% of the heat has been removed from the alternator. Only the heat generated by the stator remains.

In addition, the air space now available due to the removal of the rectifier which allows the twin fans attached to the rotor to work more efficiently by greatly enhancing heat dissipation too.

To further enhance cooling the housing is aluminum and acts as a heat sink. There are 2 slots on the top (see first image below) and a fan that is constantly circulating cool air over the diodes (see second image below).

Electromaax remote rectifier top

Air circulation slots

Electromaax remote rectifier fan

Air circulation fan

With the remote being up to 48” away from the alternator and engine, the device can be located next to the batteries in a generally more cooler and dryer place. Now there are no connections needed at the back of the alternator.

In essence we are splitting the alternator in half. This allows for the output of a large frame alternator in a small case alternator frame.

Due to no wiring at the back of the alternator (now done at the face of the Remote Rectifier) makes the wiring hookup much simpler too.

Engine mounted remote rectifierThe remote rectifier is three times larger than the bridge rectifier which is found in the standard GenMaax. The increased number of diodes greatly reduces thermal falloff which is the general cause of reduced power transfer as the alternator (stator rotor) heats up.

As a result, the hot and cold ratings are substantially improved in both cases.

All marine alternators that are subjected to 50% of normal internal heat generation will last significantly longer.

General Benefits

  • Substantial reduction of heat generated within the alternator windings
  • Greater overall heat dissipation
  • Increased longevity of the alternator
  • Allows the alternator to provide more amperage to the battery for longer periods of time

Alternator Kits

You can purchase a full kit which contains one of our CSR or Pro external smart voltage regulators for more reliable performance:

E-Maax Pro External Smart Regulator

  • 12 V, 215 Amp. alternator
  • 12 V, 215 Amp. alternator – includes E-MAAX CSR smart regulator
  • 12 V, 215 Amp. alternator – includes E-MAAX Pro smart regulator
  • 12 V, 250 Amp. alternator
  • 12 V, 250 Amp. alternator – includes E-MAAX CSR regulator
  • 12 V, 250 Amp. alternator – includes E-MAAX Pro regulator
  • 24 V, 165 Amp. alternator – includes E-MAAX CSR smart regulator

What else is included in the alternator kits?

Each kit includes the following:

  • 1 x GenMaax 165, 215 or 215 Amp 12/25 V alternator
  • 1 x E-MAAX CSR or Pro Smart Regulator
  • 1 x Alternator Temperature Sensor
  • 1 x Battery Temperature Sensor

Since no internal regulator is fitted in the GenMaax 24V alternator, the MSRP includes an E-MAAX CSR smart regulator.

GenMaax Design and Technology

The GenMaax is designed for the serious or blue-water cruiser. It’s a small to medium case with enhanced cooling. It is available in 215 and 250amp output.

Watch the video below to see show the GenMaax Alternator being tested:

Today’s batteries like AGM, Gel or Lithium batteries require a specific voltage when charging, and since that is a feature no internal regulator can offer, we recommend you couple the GenMaax with the E-MAAX smart exterior regulator. The combination of these two technologically advanced products charges batteries much faster and increases the longevity of your battery bank.

The GenMaax alternator produces continuous power output which is sufficient to simultaneously charge batteries and power on board conveniences at a low RPM, and for a very long time without suffering any degrade – and doing so while sustaining temperatures of 55C. Faster charging at the appropriate voltage means you use less fuel and increase the life of your batteries.

All 12 volt GenMaax alternators are available with your choice of internal or external regulators and 24 volt GenMaax alternators are available with external regulators only.

Customer Support

Upon purchase, your technician will contact you prior to shipment to discuss your purchase and to ensure you get the right parts and experience the smoothest installation possible.


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