Greenwill Power

Marine Energy Storage System

Safety first.
Simple to integrate.
Efficient in operation.

A DNV Type Approved LFP battery platform designed to reduce onboard battery risks, simplify vessel integration, improve efficiency and support demanding hybrid operations.

  • Extreme Safety: Cell-level thermal runaway isolation.
  • 10,000+ Cycles: Industry-leading lifespan.
  • Plug-and-Play: cable connections only.
  • Powerful and robust: peak 2.27C / heavy duty 2C / continuous 1.5C Discharge
  • Zero Liquid Cooling: Natural air-cooling simplicity.

Inherent cell-level safety

Small cylindrical LFP cells with steel casing and an individual CID in every cell.

No off-gas duct

DNV-approved architecture with no thermal runaway off-gas duct required.

No liquid cooling

Natural air cooling reduces auxiliary systems, complexity, maintenance and improves efficiency.

High-power ready

Up to 2C heavy-duty discharge capability for peak loads and demanding vessel modes.

From battery specifications to vessel value

FOR SHIPOWNERS & OPERATORS

Low fire-propagation exposure: No cell-to-cell heat propagation design with individual CID protection.

Operational flexibility: High discharge capability supports transient loads, hybrid propulsion and DP-related demand.

Lifecycle value: 10,000+ cycles at 80% DoD, with remote diagnostics and health monitoring.

FOR SHIPYARDS & INTEGRATORS

Simple integration: No off-gas duct and no liquid-cooling circuit.

Compact modular architecture: Multiple rack heights support different battery-room arrangements.

 Lower auxiliary burden: Natural air cooling and wide operating range simplify thermal management.

Engineered for
Marine Excellence

Safety-Centric Design

Cell-level thermal runaway containment. IP67 protection (validated by saltwater immersion tests).

High C-rate performance

Discharge: Peak 2.27C (5 min); Heavy Duty 2C (10 min); Continuous 1.5C 
Charge: 1C Continuous

Long life cycles

10,000+ cycles @80% DoD; 4,000+ cycles @100% DoD

Simplified Thermal Management

Natural air cooling by ventilation

Wide Operating Range

Charge: -10°C to 55°C Discharge: -20°C to 65°C (cell surface)
*Under -10~0°C, charge only at 0.1C up to SoC 30%

Efficiency

Low-heat LFP cells reduce energy losses.
Passive natural cooling with no pumps or motors cuts
auxiliary power consumption.

Cell

Modules

  • Config: 16S24P (51.2V, 110.4Ah, 5.65kWh).
  • Design: IP67-rated steel enclosure; cylindrical cells feature enhanced surface area and spacing, facilitating efficient natural cooling.
  • Physical: 345 × 486 × 221 mm (W×D×H); 54.4kg.
  • Performance: Max 110A continuous charge (1C), Max continuous 220A (2C); 250A 5 min (not recommended for long time)

BMS

  • 3-Tier Architecture:
  • BAU (Battery Array Unit): Central control.
  • BMU (Battery Management Unit): Per-string monitoring.
  • BSU (Battery Sub-Unit): Cell-level SoC/SoH tracking.
  • Features: Multi-string support, fault isolation, remote diagnostics via Starlink/G60.

Certifications

  • DNV TA Certificate
  • LR & BV Certifications in process
  • Safety Tests:
  • Thermal Runaway: UL9540A-compliant (gas release <0.5L/Ah).
  • Saltwater Immersion: IP67 validated (CNAS L5998).
  • Flame Resistance: 1-hour external fire test (CNAS L6957).

System Configuration

Greenwill Power offers a highly customizable BESS designed to fit the unique layout of any battery room. 
Our modular racks are scalable in height, with each rack housing a dedicated High Voltage Control Box (HVCB) and a flexible number of series-connected battery modules (occupying up to 17 of 18 available slots, for example). 
Multiple strings can be connected in parallel, providing a tailored power and energy solution for diverse marine applications.
System Specifications
Rack Heights2313 mm (R18), 1827 mm (R14), 1341 mm (R10)
Rack Width & DepthW8700 mm, D500 mm
Cell typeLFP 4.6Ah Cylindrical
Single module Energy / Nominal Voltage5.65 kWh / 51.2V
Single string Max. Voltage1000 V
Max. Gravimetric Density - String91.5 Wh/kg (R18), 90.5 Wh/kg (R14), 88.5 Wh/kg (R10)
Max. Volumetric Density - String95.5 Wh/litre (R18), 92.5 Wh/litre (R14), 87.2 Wh/litre (R10)
Max. Energy Density footprint - String229 kWh/m²
Performance Specifications
Discharge C-rate2.27C (5min) / 2C (10min)
Charge C-rate - Continuous1C
Cycle Life (80% DoD, 1C/0.5C)10,000
Safety Specifications
Thermal Runaway Anti-PropagationIntrinsic cell level thermal runaway isolation with small LFP cylindrical cell
Disconnect CircuitString level with HV breakdown
Short Circuit ProtectionCID in each cell and fuse in battery string level
Emergency Stop CircuitHard-wired
Disconnect Switchgear ratingFull load
Off-gas ductNot necessary
General Specifications
Communication ProtocolCAN or Modbus
Class ComplianceDNV, BV, LR (BV, LR certification ongoing)
Ingress ProtectionModule: IP67 | System: IP65
CoolingNatural air-cooling | Ventilation

System Example

Example System 1MS001-17-10
System Configuration10 strings each comprising of R18 racks with 1x BAU
Energy961 kWh
Voltage (Min/Nom/Max)789 / 870 / 979 V
Dimensions & Weight (H x W x D / Mass)2313 x 8400 x 500 mm / 10497 kg
Energy Density91.5 Wh/kg | 103 Wh/litre
Example System 2MS001-13-10
System Configuration10 strings each comprising of R14 racks with 1x BAU
Energy735 kWh
Voltage (Min/Nom/Max)603 / 666 / 749 V
Dimensions & Weight (H x W x D / Mass)1827 x 8400 x 500 mm / 8123 kg
Energy Density90.5 Wh/kg | 99.1 Wh/litre
Example System 3MS001-09-10
System Configuration10 strings each comprising of R10 racks with 1x BAU
Energy509 kWh
Voltage (Min/Nom/Max)418 / 461 / 518 V
Dimensions & Weight (H x W x D / Mass)1341 x 8400 x 500 mm / 5749 kg
Energy Density88.5 Wh/kg | 92.4 Wh/litre

DNV Approved
Product Installation for Classified Vessels

This approval underscores our dedication to innovation, rigorous quality standards, and delivering reliable solutions for the maritime industry.

We are thrilled to announce that GNW Power Limited has received official DNV approval, confirming compliance with DNV rules for classification – Ships, offshore units, and high speed and light craft. This certification verifies that our products are accepted for installation on all vessels classed by DNV, in line with the relevant DNV guidelines and standards.

Engineered for Reliability:
Our Comprehensive Testing

Our batteries undergo stringent safety evaluations to deliver unmatched reliability and performance in every scenario.

Robust Saltwater Trial
  • Survives 3-minute saltwater exposure.
  • Safe discharge with heat/smoke.
  • No damage after 7-day monitoring.
Intensive Flame Resistance Evaluation
  • Damage limited to single cell.
  • Neighboring cells continue functioning.
  • Steel casing withstands over 1000°C
Heat Propagation Safety Test
  • Overcharged cells activate CID successfully.
  • No fire or explosion observed.
  • Module maintains normal operating voltage.
Thermal Runaway Resilience Test
  • CID triggers during controlled overheating.
  • Produces only 6.9L gas volume. Less gas than competing brands.

Why Choose Greenwill?

  • Global Support:
  • Remote monitoring and diagnostics via Starlink.
  • Performance: Max 110A charge (1C), Max continuous 220A (2C 10Min) / 250A (2.27C 5 min)
  • 10.8GWh annual cell production with fully automated, eco-efficient lines.

Engineered for the Sea,Trusted by Innovators.

Greenwill · Guangzhou, China

Email: info.marine@gnwpower.com