The Mega-Guard Electric Energy Storage (EES) is an advanced system for electric energy storage for marine environment. Sailing and silent running on stored electric energy becomes a reality with Mega-Guard EES.  The  Mega-Guard EES consists of the following main components:

  • GreenBattery
  • GreenBattery BMS
  • Battery Rack

Energy storage systems in between 40kWh and 12MWh can be built with Mega-Guard EES.

Two versions are available: 

  • GreenBattery-Energy; optimized for low volume and weight
  • GreenBattery-Power; optimzed for fast charging and discharging






GreenBattery makes use of the extremely safe LiFePO4 (or LFP) chemistry. Safety can be compared with traditional lead acid batteries and are much safer than Li-ion NMC technology which is used by other marine battery manufacturers. In addition, life time and temperature range of LiFePO4 are much better when compared with Li-ion NMC batteries. GreenBattery has relatively low weight and small volume per stored kWh. In fact, GreenBattery is one of the lightest batteries
available for marine energy storage and occupying minimum floor space.

Each GreenBattery has a capacity of 10kWh and a nominal DC bus voltage of 96VDC. GreenBattery can be cooled either by liquid or by forced air (GreenBattery-Energy only). GreenBattery is totally enclosed and includes a built-in slave battery monitoring system which communicates with the GreenBattery BMS. GreenBattery fulfils the latest class requirements and
includes a pressure based safety release which should be vented to the outside environment. Up to 10 GreenBatteries can be wired in a string and the GreenBattery BMS monitors and controls the string. Up to 120 strings can be wired in parallel.









GreenBattery BMS


The GreenBattery BMS monitors and controls a string of GreenBatteries. All external connections (DC bus, Ethernet, cooling and venting) of a string are made on the GreenBattery BMS. A 5,7” touchscreen Operator Panel with built-in controller is mounted in the front of GreenBattery BMS. The state of charge (SOC), voltages and temperatures of a string can be read on the
touchscreen Operator Panel. The controller takes care of cell balancing, cooling control and safety functions. In addition, the controller is equipped with quad Ethernet ports for communication to external Mega-Guard High Power Inverters for battery charging and to a Mega-Guard Energy Management System. The GreenBattery BMS contains as well a DC bus contactor with pre-charge. A temperature controller is built inside GreenBattery BMS for external valve (liquid cooled) or for external fan
(air cooled) control. A liquid cooled EES does not heat up the battery room.  An air cooled EES should be equipped with additional air conditioning capacity to take away the heat of each GreenBattery-Energy (0,22kW). The recommended ambient temperature of battery room and liquid cooling fluid (in case of liquid cooling) is 22°C in order to reach highest life cycle of the ESS.  


Battery Rack

GreenBatteries and the GreenBattery BMS are placed in a specific designed Battery Rack. The Battery Rack contains cooling channels (air or liquid) and makes it possible to exchange a GreenBattery by sliding out and in.  Battery Racks are supplied in two different mechanical lay-outs: a vertical one for space saving and a horizontal one which is applied when not enough room
height is available. Battery Racks need to be installed in a battery room in accordance with class regulations.

The following Battery Racks are available:








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Contact information

Praxis Automation Technology
Zijldijk 24A,
2352 AB Leiderdorp
The Netherlands

+31 (0)71 5255 353

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