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eFlex MAX 5.4kWh

Discover the power and flexibility of the eFlex MAX 5.4 LFP Battery, designed to thrive in the most demanding environments and weather conditions. This top-tier lithium battery combines advanced technology with practical design to meet a wide range of energy needs while ensuring utmost safety and reliability.

Seamlessly integrating with our Fortress Power Envy inverters, the eFlex MAX enhances your system’s performance. Perfect for both home and business. Whether you’re seeking to reduce your environmental impact, energy costs, or rely on a steady power supply during outages, the eFlex MAX is your go-to solution. Make the smart switch to a greener, more efficient energy system today with our innovative battery technology.

Supported Applications:



Available in LATAM starting 6.1
Available in USA / Hawaii / Alaska / PR / USVI ​starting 7.15

Key Features:

High Cycle Life: Utilizes Tier 1 Automotive Prismatic Lithium Iron Phosphate Cells for unmatched durability.

Enhanced Thermal Performance: Patented enclosure design offers four times the thermal efficiency of competitors.

Weather Resistant: Features an IP65 rating, making it dust and water-resistant for reliable outdoor use.

Versatile Mounting Options: Includes wall mount, floor-stand, and 19-inch industrial server rack configurations.

Comprehensive BMS: Digital Processor Battery Management System with minimal idle consumption, integrated 125A breaker, and advanced monitoring capabilities.

Communication and Updates: Supports Canbus and Modbus, OTA firmware updates, and remote monitoring.

Broad Compatibility: Advanced closed-loop communication compatible with most 48V inverters.

Whole-Home Backup One-Line Diagram


Meet the 48V Family

Welcome to the Fortress Power 48V family, where cutting-edge technology meets top-tier energy solutions. Our 48V lineup is crafted to empower homes and businesses with efficient, reliable, and sustainable power. Each product in this family is designed with precision to offer optimal performance and resilience, ensuring that your energy needs are met with unmatched expertise and care.