A Smarter, Cleaner Storage Solution.

Whether you’re on or off-the-grid, Fortress Power offers advanced energy storage to maximize your solar investment.

Ideal for off-grid and emergency backup for grid outages
2X more cycles than Tesla’s Power Wall
Safe LFP Chemistry — Safer than older Cobalt-based lithium
Unmatched stability with it robust Battery Management System
10-year warranty; up to 6,000+ cycles

The Fortress eFlex 5.4 kWh Lithium Battery

Add on as you go with the eFlex 5.4 kWh modularized battery system.

Scale up on your terms with the affordable, safe, high capacity eFlex Lithium Ion Phosphate battery system.

Easy installation
Modular format allows you to add-on as you need more storage
Server racks for easy expandability
Wall mounted, floor-standing or rack-mounted
Ideal for off-grid and grid backup power
Built in Wi-Fi & remote monitoring
High output, robust design
Faster charging

eFlex 5.4 kWh Specifications

Total Energy: (kWh): 5.4
Max. Charge Current (Continuous) [A]: 55
Max. Discharge Current (Continuous) [A]: 68
Max. Pulse Current (for 5 sec) [A]: 130
Capacity [Ah]: 105
Voltage Range [V]: 44-58.4
Charging Temperature [F]: 32 to 113
Discharging Temperature [F]: 32 to 140
Storage Temperature [F]: 32 to 95
Dimension [L x W x H, inch]: 21.5 x 17.5 x 7.2
Weight [lbs]: 116
Life Cycles: 6000 @ 80% DoD
Round Trip Efficiency: >99%

The Fortress eVault 18.5 kWh Lithium Battery

Super Charge Your Energy Storage with the eVault 18.5 kWh Lithium Battery.

The built-in battery management system integrates multilevel safety concepts for excellent performance:

Grid-tied storage & off-grid ready
Built-in LCD display for voltage, state of charge, power output and operating status
Overcharge & overcurrent protection
Overheat protection
Cell monitoring & balancing
Expandable from 18.5 kWh to 222 kWh

eVault 18.5 kWh Specifications

Total Energy: (kWh): 18.5
Capacity [Ah]: 360
Nominal Voltage [V]: 51.2 (48)
Voltage Range [V]: 45-58.4
Recommended Charge Current [A]: 100
Max. Charge Current (Continuous) [A]: 170
Max. Discharge Current (Continuous) [A]: 180
Max. Pulse Current (for 5 sec) [A]: 200
Charging Temperature [F]: 32 to 113
Discharging Temperature [F]: 32 to 113
Recommended Storage Temperature [F]: 50 to 95
Dimension [L x W x H, inch]: 38.8 x 19.2 x 21.3
Weight [lbs]: 476
Enclosure Protection Rating: IP21
Mounting Options: Floor Standing
Certificates: UL 1624
Warranty: 5/10 Years
Scalability: Maximum 12 in Parallel (222 kWh)
Communication: CAN/RS485
High Current Circuit Breaker: 250A
Round Trip Efficiency: >98%

Compatible Inverters for the eFlex & eVault

Sol-Ark	8 KW & 12 KW Inverter	AC or DC coupled
Schneider	Conext XW MPPT charge controller; Conext XW+/XW pro series	AC or DC coupled
Outback	Skybox, FLEX max charge controller (48V), FLEXpower series (48V); Radian series (48V); FXR(A) and FXR (E) series (48V); GVFX and GVFX series (48V);	AC or DC coupled
Magnum	MS 4448PAE; MS 4048-20B	AC or DC coupled
SMA	SUNNY ISLAND 4548-US/6048-US; SUNNY ISLAND 3.0M/4.4M/6.0H/8.0H	AC coupled
Victron	Phoenix VE.Direct Inverter; MultiPlus and Quatro Inverter/Charger; Skylla-TG Charger; General; Color Control or Venus GX	DC coupled
Morning Star	TriStar MPPT 600V; TriStar MPPT; Tristar PWM	DC coupled
Midnite Solar	Solar Classic 150, 200 & 250; Solar Classic 150, 200 & 250-SL	DC coupled