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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-Ark8 KW & 12 KW InverterAC or DC coupled
SchneiderConext XW MPPT charge controller; Conext XW+/XW pro seriesAC or DC coupled
OutbackSkybox, 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
MagnumMS 4448PAE; MS 4048-20BAC or DC coupled
SMASUNNY ISLAND 4548-US/6048-US; SUNNY ISLAND 3.0M/4.4M/6.0H/8.0HAC coupled
VictronPhoenix VE.Direct Inverter; MultiPlus and Quatro Inverter/Charger; Skylla-TG Charger; General; Color Control or Venus GXDC coupled
Morning StarTriStar MPPT 600V; TriStar MPPT; Tristar PWMDC coupled
Midnite SolarSolar Classic 150, 200 & 250; Solar Classic 150, 200 & 250-SLDC coupled

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