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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​

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

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

Ready to take your energy storage to the next level? Request a quote today.