Hybrid Electric Catamaran with lithium-ion battery system


Hybrid Electric Catamaran equipped with RS battery modules

Herley Boats in New-Zealand introduces the new Herley 3400 hybrid catamaran. An absolutely one of a kind luxury motor yacht. The catamaran is equipped with a hybrid system. Therefore two electric drives are powering the yacht. In electric mode the MG lithium-ion batteries are taking care of emission free propulsion. At the same time the catamaran operates completely in silence. The Herley 3400 hybrid catamaran combines a unique blend of classical styling with the highest level of engineering.

Passengers on board can enjoy long days on the water with a minimal impact on the environment. Therefore the Herley 3400 has the ability to run on batteries only. In addition it is possible to switch on the generator to guarantee a long range. Moreover both systems can work simultaneously. As a result the Herley 3400 cruises in combined power from both the generator and the batteries at the same time.

Hybrid Drive modes

The following modes are available:

  • 100% Electric
    In this mode the advantages are: zero fuel burn during cruising and 0% emission. This saves the environment. On the same hand this mode saves fuel and maintenance costs. Furthermore in this mode the yachts cruises in silence without any vibrations. 
  • Economy cruise for greatest fuel efficiency
    Switch on the generator to cover long distances. For instance to make a long holiday trip. The economy mode ensures an extended range up to 2500 nautical miles. 
  • Performance mode for high speed operation
    To provide maximum power for short periods, the generator and batteries work simultaneously.

MG lithium-ion batteries are powering the electric drives in electric mode. The catamaran cruises noiseless, without producing any harmful exhaust gases.

Electric propulsion range in electric mode

A total of 8 pieces battery modules are connected in series. This results in an available capacity 67.2 kWh.  The battery bank allows the Herley 3400 to cruise in electric mode for 6 hours. In addition a generator can extend the range up to 2500 nautical miles.

The hybrid system

  • Two electric motors, each with a continuous power of 60 kW and a peak power of 100 kW
  • A high-voltage MG lithium-ion battery bank with a capacity of 67.2 kWh
  • The 120 kW diesel generator can be switched on for on-board charging
  • The cruise range is 2500 nautical miles at 8 knots
  • Maximum speed is 20 knots
  • Cruise Speed is 14 knots

High-voltage battery bank for electric propulsion

Eight lithium-ion batteries are installed to power both electric drives. The RS battery is a modular building block. The modules are available in voltages from 44 Vdc up to 88 Vdc.

This catamaran is equipped with the 44 Vdc battery modules. Subsequently, connecting eight of these modules in series results in a nominal system voltage of 350 Vdc.

The RS battery modules are liquid-cooled. This ensures the highest performance. Many life-cycles up to 8000 are possible thanks to this cooling method. The RS battery module comes with DNV-GL type approval as a standard. Therefore the RS battery module is an excellent choice for mega-yachts and commercial vessels.

RS liquid cooled lithium ion battery module DNV GL Type Approval

Thanks to the liquid cooling of the RS battery module, the highest performance is guaranteed.

Battery Monitoring System (BMS):  MG Master HV

Most importantly the MG Master HV is the monitoring and control unit for the battery bank. In other words it is the Battery Monitoring System (BMS). In short the specifications and functions are:

  • Suitable for battery banks up to 900 Vdc and 500 A
  • Integrated pre-charge circuit
  • Safety contactors in positive and negative power paths
  • High-Voltage Interlock Loop (HVIL)
  • Internal event logging
  • CAN-Bus communication including NMEA2000
  • State-Of-Health and State-Of-Charge tracking
  • Monitoring of all essential battery parameters (for instance cell voltage, temperatures, balancing)

The MG Master HV is above all the safety and control unit for the battery modules. It is available for systems up to 900 Vdc. As an example, the system on board has a nominal voltage of 350 Vdc.

BMS DNV GL Type Approval

High-voltage lithium-ion battery bank schematic

hybrid catamaran hihg voltage lithium-ion battery bank schematic lay-out

Related links

Herley Boats (New Zealand)

Moreover, the company Electric Boat, also based in New Zealand. The professionals of Electric Boat took care of the entire electric installation.

Related products

MG RS series
Product information of the installed batteries

MG Master HV
In addition click on the link below to gain more information about the installed BMS

MG Energy Monitor
Further to make your installation complete, read more about this advanced display.  Stay in control of the energy consumption during your trip on the water