Fortress Power 5kW Lithium


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Fortress Power 5kW Lithium Deep Cycle Solar Battery – Quite possibly the most well-made battery on the market, the eFlex 5.4 kWh lithium battery from Fortress Power comes with built-in wifi for remote monitoring and troubleshooting to complement its 10-year warranty with the safe and premium prismatic Lithium-Iron-Phosphate cells. It’s expandable from 5.4 kWh to 81 kWh for whatever your application needs making this one of the most popular units in the Fortress line-up.

Fortress Power 5kW Lithium Deep Cycle Solar Battery


  • High Durability and long-lasting: 10 Year Warranty with the safe and premium prismatic Lithium-Iron-Phosphate cells
  • Versatile Applications: Expandable from 5.4 kWh to 81 kWh for residential, commercial, railway, military, and telecommunications applications
  • Lowest Cost Per Cycle: High energy throughout with exceptional life span (6000+ cycles) and high round-trip efficiency (>99%)
  • Monitor from Anywhere: The battery has a built-in data storage Wi-Fi for remote monitoring and troubleshooting ability
  • Waterproof and saltwater resistant: The sleek-looking aluminum cabinet has IP65 waterproof rating to prevent salt-water corrosion

Fortress Power 5kW Lithium

Fortress Power 5kW Lithium Specifications

  • Total Energy: 5.376 kWh
  • Nominal Voltage: 51.2(48)V
  • Voltage Range: 45-58.4 V
  • Max. Charge Current(Continuous): 100 Amp
  • Max. Discharge Current(Continuous): 100 Amp
  • Recommend Storage temperature: 32 to 95 F
  • Charge temperature: 32 to 113 F
  • Capacity: 105 Amp-hour
  • Dimension (H x W x D): 7.2″ x 17.5″ x 21.5″
  • Weight: 116 lbs

Fortress Power 5.4kW Lithium Deep Cycle Solar Battery Are Compatible with most inverters! The eFlex5.4 is compatible with most inverters on the market today, but customers have found the best pairing with the units below:

  • Sol Ark
  • Outback Radian Series
  • Schneider Conext

Fortress Lithium Iron Phosphate batteries are designed to work with most 48VDC inverters and chargers available on the market. Below is a list of compatible inverters and chargers.

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

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4,000 to 5,999 Watts


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