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

The Fortress Power eVault MAX 18.5 kWh is a high-capacity, scalable Lithium Iron Phosphate (LFP) battery designed for residential and light commercial energy storage. Offering a massive 18.5 kWh of usable energy in a single unit, it features an intelligent Battery Management System (BMS) with a built-in LCD screen for real-time monitoring. It is compatible with most 48V hybrid inverters and can be scaled up to 370 kWh for large off-grid or grid-tie applications.

Product Specifications

• Capacity: 360 Ah / 18.5 kWh

• Voltage Range: 48V – 58.4V

• Max Charge/Discharge: 180 A (9.2 kW)

• Peak Surge: 230 A (12 kW for 30 min) / 250 A (12.8 kW for 5 sec)

• Round Trip Efficiency: > 98%

• Recommended Charge Current: 150 A

Why Choose eVault MAX 18.5

The eVault MAX 18.5 is the top choice for homeowners and businesses that need massive storage capacity without managing a dozen small battery modules. A single unit provides enough power to run a standard home overnight. Its robust IP55 aluminum enclosure and serviceable top-cover design make it durable and easy to maintain, while its ability to scale up to 20 units ensures it can grow with your energy needs, from a simple backup system to a full microgrid.

Benefits of eVault MAX 18.5

• Massive Single-Unit Capacity: With 18.5 kWh per unit, you need fewer batteries to achieve your desired backup duration, simplifying installation and wiring.

• Smart Monitoring: The integrated LCD touchscreen displays vital data like State of Charge (SoC), voltage, current, and cell status, giving you immediate visibility without needing a separate app.

• Universal Compatibility: It is “inverter agnostic,” working seamlessly with leading 48V inverters like Sol-Ark, Schneider, Outback, Victron, and SMA via closed-loop communication.

• Long Lifespan: Built with safe Tier 1 prismatic LFP cells, it offers a lifespan of over 8,000 cycles, providing reliable power for decades.

General Data

• Dimensions (H x W x D): 42.2″ x 20.3″ x 20.3″ (1073 x 515 x 515 mm)

• Weight: 520 lbs (235.8 kg)

• Enclosure Rating: IP55 (Indoor / Protected Outdoor)

• Mounting: Floor Standing (includes wheels for positioning)

• Operating Temperature: 32°F to 120°F (0°C to 49°C) [Charge]; -4°F to 140°F (-20°C to 60°C) [Discharge]

• Certifications: UL 1973, UL 9540, UL 9540A, CEC, SGIP

Frequently Asked Questions

Q1: Can I install the eVault MAX outdoors?

The unit is rated IP55, which offers protection against dust and water jets. However, Fortress Power recommends installing it indoors or in a garage to protect it from direct sunlight and extreme temperature fluctuations, which can degrade performance.

Q2: Is this battery compatible with Sol-Ark inverters?

Yes. The eVault MAX has established closed-loop communication protocols specifically for Sol-Ark (as well as Schneider, Victron, and SMA), ensuring precise charging and maximizing battery life.

Q3: How heavy is it?

It weighs 520 lbs. While it comes on wheels for positioning on flat surfaces, it requires equipment (like a pallet jack or forklift) and multiple people to move safely during installation.

Q4: Can I add more eVault batteries later?

Yes. You can stack up to 20 units in parallel for a total of 370 kWh. Older units can be paralleled with new units, provided they are balanced to within 0.5V of each other before connection.

Q5: Does it have a breaker?

Yes. It includes a built-in 250A DC breaker on the front of the unit, serving as both an overcurrent protection device and an accessible on/off switch for the system.