Sol-Ark 8kW Inverter with Fortress Power eFlex 10.8kWh Battery Storage Kit

Adding storage with your PV system can be simple. Whether you have an existing grid-tie system or are planning a new project, Sol-Ark and Fortress offer a combined solution that will help you keep the lights on and your home office running during utility interruptions. “Closed-loop” communication and streamlined installation makes integrating solar with storage now easier than ever.


Components Included
Sol-Ark 8kW All-In-One-Hybrid 48V Inverter Qnty. 1
Fortress Power 5.4kWh eFlex Lithium Iron Phosphate Battery Qnty. 2
Fortress Power Battery Wall Mount Enclosure Qnty. 2
FW500 DC Enclosure Qnty. 1
Sets of 2/0 Battery to Inverter Red and Black Cables Qnty. 2

Sol-Ark 8K Generator – Inverter

Sol-Ark 8K > 8,000 Watt 48 Volt All-In-One Solar Generator – Inverter
Manufacturer Part Number: 8K

Sol-Ark 8K All-In-One Solar Generator System

Grid Tied Mode, Meter Zero, Time of Use, Smart Load, Peak Shaving, 7kW AC Coupling

Max allowed PV Power 11,000W
Max allowed PV Power per MPPT 6,000 Watts
Max DC voltage 500V
MPPT voltage range 150-425V
MPPT Starting Voltage 175V
Number of MPPT 2
Nominal AC Output Voltage 120/240V split phase
Peak Inverter Efficiency 97.5%
Continuous AC power to Grid (On Grid) 9000W 37.5A L-L (255 V)

4800W 40A L-N (120V)

Continuous AC power to Loads (Off-Grid) 20,000VA L-L (240V)

10,000VA L-N (120V)

Battery Type Lead-Acid or Li-Ion
Nominal DC Input 48V
Capacity 90 – 2000Ah
Grid to Battery Charging Efficiency 96.0%
Dimensions (H x W x D) 30.0” x 18.30” x 10.00”
Weight 78 lbs

Product Features

  • Next Generation Efficiency
    3X Better! Only 4% losses vs. 14% in today’s battery based systems
  • Split Phase & Three Phase
    Sol-Ark’s 8K pumps out power just like the grid, allowing you to power 120V/ 240V appliances
  • Grid-Tied, Hybrid, Off-Grid
    Manages power from Solar, Battery, Grid, Load, and Generator simultaneously
  • Flexible
    Sol-Ark is expandable from 5 to 36 (11 kW) solar panels and 0-32 batteries.
  • 5-Year Standard Warranty
    10-Year extended warranty available

Helpful Hint with Sol-Ark hybrid inverters: Unlike most string inverters – Sol-Ark hrybid inverter solution will not have a complete power loss for a series string of modules if one of the panels goes bad (stops producing) *** so as long the total voltage of the remaining panel meets or exceeds the min mppt voltage range of 150VDC.

Fortress Power > 48 Volt 5.4kWh (105AH) Lithium Iron Battery

The eFlex 5.4 kWh 48 Volt Lithium Iron Battery by Fortress Power is a safe, scalable solution for any projects energy storage needs.

With built-in data storage and Wi-Fi for remote troubleshooting and monitoring. The eFlex is light years ahead of the pack. Additional features, such as the smart Battery Management System (BMS) includes relay disconnects, closed loop communication for many hybrid inverters, cell voltage and temperature monitoring, and cell balancing to maximize reliability and longevity, as well as wifi for internet-of-things compatibility.

The Fortress Power eFlex has the highest round-trip efficiency in the industry at 98% efficiency.

Also, this battery has several mounting options such as wall mount, floor mount and server rack mount to fit your individual project’s needs.

Product Information
Model eFlex 5.4
Series eFlex
Manufacturer Fortress Power
Type Lithium Iron Phosphate (LiFePO4)
Dimensions (L x W x H) 21.5″ x 17.5″ x 7.2″
Weight 108 lbs
Shipping Method Freight
Nominal Voltage 48V
Rated Capacity (20 Hour Rate) 105 AH
Terminal Type M8

Detailed Information

Lithium Iron Phosphate Battery

The Fortress Power eFlex is a 5.4 kWh scalable energy storage solution based on safe and energy dense prismatic Lithium-Iron-Phosphate cells. The high amperage, smart Battery Management System (BMS) includes relay disconnects, closed-loop inverter communication, cell voltage and temperature monitoring, and cell balancing to maximize reliability and longevity, as well as wifi for internet-of-things compatibility. The unit can be wall mounted, floor mounted, and server rack mounted.


  • 98% Roundtrip efficiency
  • High Durability and Long-Lasting
  • Safe Lithium Iron Phosphate Technology (LiFeP04)
  • Flexible mounting options
  • Remote monitoring
  • Advanced cell level monitoring and balancing
  • Close-loop communication with many hybrid inverters
  • Canbus, Modbus, and wifi communication
  • UL 9540 certified




Documentation – Sol-Ark 12k

Documentation – Fortress eFLEX 5.4