How Brogen Delivered Battery & BMS Solution for Spain’s First All-Electric Boat

Project Background

The vessel—designed to carry heavy loads at sea—required not only a high-performance propulsion system but also an intelligent battery architecture, safe BMS integration, and thermal management that could endure harsh marine conditions. Brogen was chosen as the key electrification partner to deliver the Battery + BMS + Integration solution.

Initial Solution & Battery Architecture

The client approached Brogen with the concept for a 6-ton electric boat, requesting an end-to-end energy storage system that was powerful, scalable, and compliant with maritime safety regulations.

We initially proposed a solution using CATL’s battery platform:

• Air-cooled battery modules designed for rugged environments, eliminating the need for complex liquid cooling systems.
• Operational range between -30°C to +60°C, with only minimal ventilation required in the battery room.
• Real-time temperature monitoring sensors embedded in each cell.
• Flexible modular architecture: 27 modules, grouped into 3 series branches (9 modules per branch), connected in parallel.

Each group was controlled by a single BMS, which avoided unnecessary data transmission complexity. We also proposed hot-swappable BMS units for redundancy and a dedicated control cabinet (similar to an electric distribution box) to interface with the VCU (Vehicle Control Unit).

We guaranteed a battery degradation rate of no more than 20% over five years, assuming a maximum of 400 full charge cycles per year. The system also supported fast charging up to 180kW—a critical requirement for commercial marine operations.

Redesigning for Maritime Redundancy: Evolving to a Multi-Pack Isolated BMS Solution

However, during later project stages, our client emphasized the need to comply with stringent maritime redundancy standards. This required complete physical and logical isolation between independent battery packs—spanning electrical systems, thermal management, mechanical structures, and BMS units.

In response, Brogen pivoted to a more robust system using EVE’s industrial-grade battery modules. The final system includes:

• 2 independent group, each containing:
  • 2 battery clusters
  • Each cluster with 10 modules
• Each group is self-contained and fully isolated for redundancy.

Advanced Three-Tier BMS Architecture

The final solution uses a three-layer BMS structure for precision control and system safety:

1. BMU (Battery Module Unit) - Slave Control
   • Installed in each module
   • Monitors cell voltage and temperature
   • Alerts for over-temperature scenarios
2. BCU (Battery Cluster Unit) - Master Control
   • Installed in the high-voltage box of each cluster
   • Aggregates BMU data and manages the cluster
3. BAU/BGMU (Battery Array Unit) - Central Control
   • Installed in the group control box
   • Orchestrates the entire battery system
   • Communicates upstream with VCU and downstream with BCUs
   • Includes independent safety function modules to prevent single-point failures

Safety modules such as SBSU (Safety Battery Sensor Unit) are built into the packs for independent thermal protection and redundancy—critical for marine safety compliance.

System Components Delivered

• High-performance battery modules
• Cluster HV box
• Group HV box
• Display interface
• High- and low-voltage harnesses
• Stainless steel battery racks

System Parameters

Client Testimonial: Excellence Recognized

Following project delivery, the client sent Brogen a formal letter of thanks.

Below is an excerpt from the letter:

“I am writing to express my heartfelt gratitude for the exceptional support and collaboration provided by your team on the groundbreaking project of the first-class CCS electric ship in Spain. Your dedication and expertise have been instrumental in the successful delivery and ongoing support of this venture.”

“It has been six months since the project’s completion, and I am pleased to report that it is running exceptionally well, exceeding our expectations in many aspects.”

“Your team’s ability to address challenges with professionalism and efficiency has been a major factor in the project’s success.”

Our Carbon Commitment: Supporting Marine Decarbonization

Ships account for nearly 3% of global greenhouse gas emissions, and the maritime industry is under growing pressure to decarbonize. From harbor tugboats to inland ferries, Brogen believes electrification is not only possible—it’s necessary.

We are committed to helping shipbuilders, fleet operators, and governments transition to electric marine platforms. With advanced Battery, BMS, and thermal management solutions tailored for harsh marine conditions, we offer global support for low-carbon transformation.

Whether you're designing a commercial vessel, offshore workboat, or pleasure craft, we’re ready to power your next-generation marine project—safely, efficiently, and sustainably.

Partner with Brogen Today

Looking to electrify your boat or marine fleet with reliable battery and BMS solutions? Contact Brogen’s technical team to explore tailored solutions for your maritime decarbonization goals.