ABS has issued a Product Design Assessment to Fleetzero for its Leviathan™ Battery Energy Storage System, making it the first U.S.-manufactured LFP marine battery to achieve classification approval. Operating at up to 1,000 VDC with an IP67 rating, the modular system bridges the confidence gap for ship electrification by offering safe, scalable energy storage. Commercial deployment begins later this year, highlighted by a 10 MWh installation for a vessel’s hybrid-electric propulsion conversion.
Houston | August 11, 2026 – In a landmark development for maritime energy storage and vessel electrification, the American Bureau of Shipping (ABS) has issued a Product Design Assessment (PDA) to Fleetzero for its flagship Leviathan™ Battery Energy Storage System (BESS).
The certification marks a historic threshold: the first lithium iron phosphate (LFP) marine battery system manufactured entirely in the United States to receive classification approval.
Engineering for Extremes: Inside the Leviathan™ Platform
The ABS Product Design Assessment represents a comprehensive engineering review of the Leviathan system, evaluating its safety, structural integrity, and operational resilience under rigorous marine criteria. The system is designed to support future-ready, class-verified vessel retrofits and newbuilds.
Key technical specifications of the Leviathan architecture include:
- Chemistry: Lithium Iron Phosphate (LFP), chosen for its exceptional thermal stability, inherent safety, and absence of critical transition metals like nickel, cobalt, or manganese.
- Voltage Architecture: Operates at up to 1,000 VDC to integrate smoothly with modern high-power marine microgrids and propulsion drives.
- Operational Range: Supports a wide depth of discharge envelope from 2% to 98%, maximizing usable energy per cycle.
- Environmental Protection: Carries an IP67 rating, engineered to withstand high-moisture, high-salinity, and electromagnetic interference (EMI) environments typical of open-ocean and offshore operations.
- Modular Scalability: The containerized, rackless architecture allows modules and strings to be scaled seamlessly across diverse vessel classes, from harbor tugs to deep-sea cargo ships.
Bridging the Confidence Gap in Ship Electrification
As shipowners navigate tightening global carbon regulations and look for practical pathways to reduce emissions, class verification acts as a critical de-risking mechanism.
“As the industry works through the practical challenges of electrification, class-verified battery technology plays an important role in building confidence among owners and integrators,” noted Gareth Burton, ABS Senior Vice President, Global Engineering. “The PDA for the Leviathan system reflects the rigorous technical work required to bring a new marine battery solution to market safely.”
For Fleetzero, which has positioned itself at the forefront of domestic marine technology, the approval validates years of iterative R&D and exhaustive physical testing.
“This approval is the result of years of disciplined engineering and close collaboration with ABS,” said Steven Henderson, CEO and Co-Founder of Fleetzero. “The maritime industry needs proven, class-approved energy storage that is built on a safe, scalable chemistry. The Leviathan delivers exactly that, and we are putting it to work immediately.”
Commercial Momentum: Setting Sail Later This Year
The Houston-based company is wasting no time translating regulatory approval into commercial deployment. Fleetzero confirmed that the first commercial rollout of the Leviathan system will hit the water later this year.
The inaugural project will deploy a substantial 10 MWh of Leviathan battery capacity as a central component in a commercial vessel’s comprehensive conversion to hybrid-electric propulsion.
By securing this class approval, Fleetzero and ABS have laid a foundational stepping stone for U.S. industrial maritime manufacturing, proving that domestic clean-tech innovation can meet the strictest international classification standards.
About the American Bureau of Shipping (ABS)
The American Bureau of Shipping (ABS) is a leading international classification society dedicated to promoting the security of life, property, and the natural environment through the development and verification of standards for the design, construction, and operational maintenance of marine and offshore assets. Founded in 1862 and headquartered in Houston, Texas, ABS supports the global maritime industry with cutting-edge technical services, regulatory compliance guidance, and innovative solutions that drive sustainability, safety, and performance.
With a strong presence in over 70 countries, ABS works closely with shipowners, operators, shipyards, equipment manufacturers, and regulators to deliver practical insights into evolving technologies and environmental standards. As a trusted advisor, ABS plays a pivotal role in enabling the transition to low- and zero-emission shipping through research, classification, and advisory services on alternative fuels, digitalization, and decarbonization pathways.
Source: American Bureau of Shipping