The FlexTower is an outdoor-rated enclosure that houses your Fortress Power Envy inverter alongside up to four eFlex 5.4 kWh batteries in one weatherproof cabinet. It's built for homeowners and installers who need a clean, code-compliant outdoor placement for an off-grid or backup power system without building a separate equipment room.
The FlexTower pairs with the Fortress Power Envy 8/10kW hybrid inverter and eFlex 5.4 kWh batteries to form a self-contained backup or off-grid power system. It's designed for applications where indoor equipment space is limited, including off-grid cabins, RVs, trailers, condos, and apartments. Note: If you would like to review the manufacturer Product Specifications, Warranty, Brochure, etc., for this system, please refer to the "Resources (System Manuals and Warranty)" Tab above on this page.
- Holds up to 4 Fortress Power eFlex 5.4 kWh batteries
- Houses one Fortress Power Envy 8/10kW hybrid inverter
- Rated for outdoor installation (also allows outdoor placement of the normally indoor-only Solo 6.5K inverter)
- Compatible with Fortress Power Envy Inverters, Solo 6.5K Inverter, Guardian monitoring products, and DuraRack/FlexTower accessories per manufacturer product compatibility listing
- NOT confirmed compatible with eFlex MAX, eVault MAX, LFP-10 MAX, eForce, or eBoost batteries [NEEDS VERIFICATION]
- NOT confirmed compatible with Envy True 12 or Envy Duo 21 inverters based on provided data [NEEDS VERIFICATION]
- Iron/steel outdoor-rated enclosure construction (per FlexTower/DuraRack family design)
- Integrated busbar wiring path shared with the DuraRack enclosure family
- Enables outdoor deployment of inverters otherwise restricted to indoor use (Solo 6.5K)
- Free-standing or pad-mounted installation options
- Single enclosure reduces field wiring runs between battery bank and inverter
| Spec | Value | Unit |
|---|---|---|
| Battery Capacity (this configuration) | 4 | eFlex 5.4 kWh batteries |
| Inverter Housed | 1 | Envy 8/10kW inverter |
| Model | FLEXTOWER | - |
Note: See "Resources (System Manuals and Warranty)" Tab above for full specifications.
- Fits: Fortress Power Envy 8/10kW hybrid inverter
- Fits: Fortress Power Solo 6.5K inverter (outdoor installation enabled via FlexTower housing)
- Fits: Fortress Power eFlex 5.4 kWh battery, up to 4 units in this configuration
- Compatible with Fortress Power Guardian monitoring products and DuraRack/FlexTower accessory line
- Does NOT confirm compatibility with eFlex MAX, eVault MAX, LFP-10 MAX, eForce, or eBoost batteries [NEEDS VERIFICATION]
- Does NOT confirm compatibility with Envy True 12 or Envy Duo 21 inverters [NEEDS VERIFICATION]
| Category | Detail |
|---|---|
| Installation Rating | Indoor and outdoor |
| Code Compliance Context | Envy inverter includes integrated rapid shutdown transmitter referenced for NEC 2017 & 2020 compliance; enclosure-specific listings not provided [NEEDS VERIFICATION] |
FAQ
How many batteries and inverters does the FlexTower hold?
This FlexTower configuration holds up to 4 Fortress Power eFlex 5.4 kWh batteries and one Envy 8/10kW inverter.
Can I install the FlexTower outdoors?
Yes. The FlexTower is rated for outdoor installation, which also allows the Solo 6.5K inverter (normally indoor-only) to be installed outdoors when housed inside it.
Will the FlexTower work with eFlex MAX or eVault MAX batteries?
The manufacturer data provided does not confirm compatibility with eFlex MAX, eVault MAX, LFP-10 MAX, eForce, or eBoost batteries in the FlexTower. Confirm with Fortress Power documentation before ordering. [NEEDS VERIFICATION]
Does the FlexTower work with the Envy True 12 or Envy Duo 21 inverters?
The provided specifications list compatibility with Envy 8/10kW and Solo 6.5K inverters. Envy True 12 and Envy Duo 21 compatibility with this cabinet is not confirmed in the source data. [NEEDS VERIFICATION]
Warranty & Registration
Manufacturer warranty terms for the FlexTower enclosure are not included in the provided specification data. Refer to the "Resources (System Manuals and Warranty)" Tab above on this page for the manufacturer's official warranty document and registration process before installation. [NEEDS VERIFICATION]
