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Fortress Envy 12kW Inverter with 4 eFlex G2 5.4kWh Batteries and Durarack Bundle

SKU Envy12KW-Durarack
Original price $16,999.00 - Original price $16,999.00
Original price
$16,999.00 - $16,999.00
Current price $16,999.00

In Stock & Ready to Ship

All orders are shipped within 1-2 business days. Product ETA 7-14 business days.

This bundle comes with 12kW inverter, 4 eFlex 5.4 kWh batteries and durarack.

Fortress Power Envy True 12 kW Inverter:

  • Comprehensive Integration: Functions seamlessly for PV, Generator, On/Off Grid, AC/DC Coupling.
  • Full Home Backup: Supports 200A AC Passthrough ensuring complete home backup.
  • High Capacity: Allows for a maximum of 18 kW PV power delivery to both the battery and AC outputs, with 12 kW (50A @240V) backup power.
  • Efficient Installation: Features integrated AC & DC breakers for swift installation and commissioning.
  • Enhanced Safety Features: Built-in APsmart Rapid Shutdown Transmitter and Button ensure safety compliance.

Key Features of Envy True 12 kW Inverter:

  • Supports 200A AC passthrough for whole home backup.
  • Triple MPPT output catering to a maximum 21 kW PV array.
  • Flexibility with AC, DC, and AC/DC coupling.
  • Robust IP65 rating suitable for both indoor and outdoor installations.
  • Integrated generator input.
  • Scalability up to 10 units in parallel.
  • Comprehensive monitoring capabilities through local and remote apps.
  • User-friendly interface with a color LCD touch screen and batch settings.

Fortress Power eFlex 5.4 kWh Lithium Batteries:

Designed to withstand diverse applications and extreme weather conditions:

  • Utilizes Tier 1 Automotive Prismatic Lithium Iron Phosphate Cells ensuring longevity.
  • Innovative enclosure design offering superior thermal performance compared to competitors.
  • Robust IP65 Dust and Water-Resistant design suitable for outdoor setups.
  • Versatile mounting choices including wall mount, floor-stand, or standard 19” industrial server rack mount.

DuraRack for Fortress eFlex 5.4 kWh Lithium Batteries:

  • Versatile Storage Solution: Accommodates up to 4 eFlex 5.4kWh batteries, facilitating a 48V UPS server rack or augmenting home solar arrays.
  • Robust Enclosure: NEMA 3R rated for resistance against water and dust, ensuring durability for both indoor and outdoor installations.
  • Integrated Features: Comes with integrated busbars and battery cables simplifying stacking.
  • Climate Adaptability: Easily add a DIN rail thermostat for colder environments, complemented by passive cooling vents for warmer climates.
  • Scalable Storage: Expands effortlessly up to 4 units, accommodating a total of 81 kWh when equipped with 15 eFlex batteries.

Document Library

Fortress eFLEX 5.4kWh Data Sheet

Fortress Power eFLEX Installation Manual

eFlex Firmware Update Guide

Fortress Power Warranty

Fortress eFlex UL9540 Certificate

Fortress - Online Inverter Integration Guides

Envy Inverter 12 kW Specifications

Envy Inverter 12 kW Install Manual

Envy Battery-inverter Integrations guide

Envy inverter Monitoring setup guide

Envy 12 Warranty

Fortress Power DuraRack Data Sheet

Fortress Power DuraRack Install Manual

Shipping Information

FREE & FAST SHIPPING SAVE Hundreds Today with Free Shipping on All Orders. We Ship to ALL 48 Lower States (We do not ship to Puerto Rico, Hawaii, Alaska)

Lead Time - 3-7 Business Days Depending on Product
 - Once You Place an Order, We immediately begin processing, the order request is sent to our warehouse and is prepared for pickup, it then usually takes around 3-7 business days to be picked up for transit.

Transit Time
 - Transit Time can vary depending on the distance between your location and the warehouse but you can expect the item to arrive between 3-8 business days after pickup.

Our Shipping Partners: FedEx, UPS, Freight Club (among others)

Shipping Partners
We partner with the most reliable freight companies in the USA to ensure your order arrives safe and in a timely manner.

Your Item will ship from warehouses all across the United States to ensure fast and efficient delivery times for our customers.

If there are any delays regarding your product shipment, we will let you know in advance. 

Order Confirmation:

As soon as you place your order, you will receive an order confirmation e-mail. (please allow a few hours for this to come through in some cases) This means that we have received your order in our system and pre-authorized your credit card for the purchase. 

As soon as we receive your order, we automatically reach out to our suppliers to confirm that it is in stock and available for immediate shipment. 

If your item is on backorder or unavailable, we will void the pre-authorization and reach out to you via e-mail.  If your item(s) are available for immediate shipment (within 5 business days), we will process the charges and submit the order for shipment.

Order Shipment:

If your order is in stock and we process the charges to your credit card, it will ship within five business days from the date of your order.  We will send you tracking information within 24 hours of your order leaving the warehouse to the e-mail address you provided when checking out.  If you do not receive tracking information from us within six business days of your order, feel free to follow up with us at sales@buildthepower.com

No Shipping outside the USA. (Some exceptions apply - if the website permits you to check out and enter your shipping address, you will receive your order. Some products in particular are available in Canada).

Shipping Options

Our base "Curb-side" Pickup shipping is always completely free! This option usually takes between 5-15 days to arrive at your doorstep, after you have submitted your order.

Threshold Shipping: This involves the item being brought onto your porch, or into a sheltered/garage area. 

Double-Check Your Address

To ensure that your package is properly delivered and that you receive your package within the time frames we advertise, please
make sure that your address is correctly entered and includes all relevant and/or required information. The use of correct
abbreviations, street numbers, building or apartment numbers, and route information (if applicable) is critical for ensuring
timely delivery. 
We do not take responsibility for lost, misplaced, or incorrectly delivered shipments if the address information
provided is incorrect or incorrectly entered at the time of purchase


Please inspect the packaging of your item(s) when they arrive, if you notice any damage, you should make note of it when signing for delivery.  If your item(s) do arrived damaged please send photos of damage, box and SKU, along with a brief description of the damage to sales@buildthepower.com and we will process an insurance claim on your behalf. Photos and videos must be sent for freight damage within 24 hours of arrival or the freight damage claim will not be valid. Any punctures, or visible signs of exterior damage must be reported within 24 hours.


10 Years

Return Information

We have a 30-day return policy, which means you have 30 days after receiving your item to request a return.

Should you decide to cancel your order prior to its shipment, a 3% deduction will be applied to cover platform fee expenses from the total paid amount.

To be eligible for a return, your item must be in the same condition that you received it, unworn or unused, with tags, and in its original packaging. You’ll also need the receipt or proof of purchase. Items that are not in this condition will not be accepted.

To start a return, you can contact us at sales@buildthepower.com If your return is accepted, we'll send you a return shipping label, as well as instructions on how and where to send your package. Items sent back to us without first requesting a return will not be accepted.

Returns for reasons other than damaged items will require a 15-25% re-stocking fee, this depends on the size and freight cost of the item to ship back, we sell large items and shipping can be costly. 

Returns/Cancellations after the item has shipped will also incur a 15-25% fee charged to you, as freight costs can be high for our products. 

If your return is outside of the 30 day return period, your item will not be accepted.

You can always contact us for any return questions at sales@buildthepower.com.


Damages and issues

Please inspect your order upon reception and contact us immediately if the item is defective, damaged or if you receive the wrong item so that we can evaluate the issue and make it right.

Items that are damaged must be communicated to us within 24 hours of receiving the item. 

Please note that if items have been taken out of the packaging and/or installed, returns may be voided depending on the manufacturer. 

Some of our manufacturers do not accept returns for specific items, this must be considered when purchasing. 

The fastest way to ensure you get what you want is to return the item you have, and once the return is accepted, make a separate purchase for the new item.


We will notify you once we’ve received and inspected your return, and let you know if the refund was approved or not. If approved, you’ll be automatically refunded on your original payment method. Please remember it can take some time for your bank or credit card company to process and post the refund too.

Contact Information

You can contact us using the methods below. 

US Customer Support Number: +1 507 636 3614
Email: sales@buildthepower.com

Free Shipping

Free shipping on all orders

In stock & ready to ship

All orders are shipped within 1-2 business days

Hassle Free Returns

Hassle free return within 30 days

Excellent Customer Service

Questions? Give us a call today (507) 636-3614

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