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eVault MAX 18.5 kWh​ | Whole-Home Power, Built to Last

A high-capacity 48V LFP battery designed for whole-home backup, seamless integration, and long-term energy independence — with 18.5 kWh of reliable storage.

Product Overview

Product Features

Product Information

Product Videos

Product Compatibility

eVault MAX 18.5kWh

Built to Last Whole-Home Power

The eVault MAX 18.5 kWh is Fortress Power’s most advanced 48V lithium iron phosphate (LFP) battery, delivering whole-home and light commercial energy storage in a compact, all-in-one design. Scalable up to 370 kWh, it’s ideal for applications ranging from off-grid living and backup power to solar self-consumption and peak demand reduction.

Engineered for simplicity and performance, the eVault MAX features AC and DC coupling options and a serviceable top-access design that makes installation faster and more reliable. Whether you’re powering a home, small business, or critical backup system, the eVault MAX offers the safety, capacity, and flexibility to get the job done.

Applications

Residential

Light Commercial

FEATURES

  • High-Capacity, Scalable Storage

    Delivers 18.5 kWh of energy storage, scalable up to 370 kWh, making it ideal for whole-home backup, large residential projects, and light commercial applications.

  • Long-Lasting Performance

    Engineered for durability with 8,000+ cycles at 80% DoD, the eVault MAX ensures dependable, long-term energy storage and lower lifetime costs.

  • Exceptional Efficiency

    Operates at up to 98% round-trip efficiency at 0.5C, maximizing energy savings and performance across a wide range of usage scenarios.

  • Smart Battery Management System (BMS)

    Equipped with a digital BMS for cell-level monitoring, automatic balancing, and enhanced safety — ensuring consistent, optimized operation.

  • Versatile Climate Resilience

    Built to perform in extreme environments with a discharge temperature range of -4°F to 140°F, ideal for both hot and cold climates.

  • Certified for Safety & Compliance

    Fully compliant with UL1642, UL1973, and UL9540 safety standards, ensuring peace of mind and simplified permitting and inspection processes.

  • Installer-Friendly Design

    Features top-cover service access for easy installation and maintenance, reducing labor time and minimizing installation errors.

  • Integrated Display & Smart Connectivity

    Includes a built-in LCD touchscreen for real-time performance metrics and supports closed-loop inverter communication for seamless energy management.

PRODUCT INFORMATION

Total Energy (kWh)18.5
Capacity[Ah]360
Nominal Voltage [V]51.2 (48)
Voltage Range[V]48-55
Recommended Charge Current [A]150
Max. Charge Current (Continuous)[A]180
Max. Discharge Current (Continuous)[A]180
Max. Pulse Current (for 10 sec) [A]200
Charging Temperature[F]32 to 120
Discharging Temperature[F]14 to 77
Dimension [H xW x D, inch]20.3 x 20.3 x 42.2
Weight[lbs]520
Enclosure Protection RatingIP55
Mounting optionsFloor standing
CertificatesUL 1642, UL1973, UL9540
Warranty10 Years
ScalabilityMaximum 20 in Parallel (370 kWh)
CommunicationCAN/RS485
High Current Circuit Breaker250A
Efficiency>98%

Manuals

Warranty

Certifications

Data Sheets

VIDEO LIBRARY

eVault MAX 18.5kWh Video Library

5 Videos

PRODUCT COMPATIBILITY

Fortress Power Envy Inverters

Fortress Power Guardian Gateway

The eVault MAX is easy to pair with your favorite third-party inverters with a simple click.

LEARN MORE

Monitor and control your eVault MAX 18.5kWh. Anywhere! Anytime!

✅ Monitor Performance of Each Battery

✅ Update Firmware Over The Air

✅ Participate in Virtual Power Plant Programs 

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