Product Description

$250 Off Orders Over $5,000
BigBattery and EG4 orders of $5,000 or more qualify for $250 off, applied automatically at checkout. No discount code required.

This kit combines stackable BigBattery ETHOS LiFePO4 batteries with the EG4 FlexBOSS18 hybrid inverter — 18 kW of PV input and 13 kW of split-phase AC output with three MPPTs, scalable design, and remote Wi-Fi monitoring. Start at 10.24 kWh of storage and configure up to 30.72 kWh for extended backup.

What's in the kit

  • 1 × EG4 FlexBOSS18 hybrid solar inverter (18 kW PV / 13 kW AC, split-phase, 3 MPPT)
  • Your choice of 2, 3, 4, or 6 × BigBattery ETHOS 48V 5.12 kWh LiFePO4 battery modules

Key features

  • Split-phase 120/240V output for standard North American home circuits.
  • Three MPPT inputs give flexibility for arrays on multiple roof faces.
  • Safety-certified battery platform: ETHOS modules are built on UL1973-listed cells with UL9540A-tested design.
  • Remote monitoring: track production and battery state from the app via Wi-Fi.
  • Scalable: stack additional ETHOS modules as your needs grow.

Good to know

Select your storage capacity from the Battery Configuration menu — pricing shown is for the complete kit. Ships by freight carrier; delivery timing is confirmed once your order is accepted. Professional installation by a licensed electrician is recommended.

Customers also bought

    • FREE SHIPPING IN USA

      Free shipping with every order

    • SATISFACTION GUARANTEED

      If your order arrives defective or fails to

      function properly, you will receive a full 100% refund!

    • PREMIUM CUSTOMER SUPPORT

      Connect with us through email, or

      phone, and we will address any questions you may have!

    • SECURE ENCRYPTED PAYMENTS

      We utilize advanced encryption to

      ensure there is never an issue with your privacy.