eFLEX MAX lithium battery pack with metallic casing, product labels, and black connectors
Green Vista Living inverter with digital display and black metal casing, front view
eFlex MAX lithium battery with labeled features like water resistance, RJ45 port, aluminum enclosure, LED indicator, integrated breaker, power button, efficiency, and included busbar
Inverter unit with warning label, control panel, ports, and silver-black casing on white background
eFlex Max connected lithium battery system with black and silver casing, wall mounted
Battery monitoring app showing 100% charge on smartphone screen in hand
Fortress Power eFlex MAX wall-mounted battery system and inverter installed indoors
eFLEX MAX lithium battery pack with metallic casing, product labels, and black connectors
Green Vista Living inverter with digital display and black metal casing, front view
eFlex MAX lithium battery with labeled features like water resistance, RJ45 port, aluminum enclosure, LED indicator, integrated breaker, power button, efficiency, and included busbar
Inverter unit with warning label, control panel, ports, and silver-black casing on white background
eFlex Max connected lithium battery system with black and silver casing, wall mounted
Battery monitoring app showing 100% charge on smartphone screen in hand
Fortress Power eFlex MAX wall-mounted battery system and inverter installed indoors

Fortress Power eFlex MAX 5.4kWh

Authorized Fortress Power Dealer | Full Vendor Warranty Included

Customers rate us 4.6/5 based on 413 reviews.
$1,499.00
$2,999.00
$1,499.00
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eFLEX MAX lithium battery pack with metallic casing, product labels, and black connectors

Fortress Power

Fortress Power eFlex MAX 5.4kWh

$2,999.00 $1,499.00
eFLEX MAX lithium battery pack with metallic casing, product labels, and black connectors
Green Vista Living inverter with digital display and black metal casing, front view
eFlex MAX lithium battery with labeled features like water resistance, RJ45 port, aluminum enclosure, LED indicator, integrated breaker, power button, efficiency, and included busbar
Inverter unit with warning label, control panel, ports, and silver-black casing on white background
eFlex Max connected lithium battery system with black and silver casing, wall mounted
Battery monitoring app showing 100% charge on smartphone screen in hand
Fortress Power eFlex MAX wall-mounted battery system and inverter installed indoors

Fortress Power

Fortress Power eFlex MAX 5.4kWh

$2,999.00 $1,499.00
  • Description
  • Why Buy From Us

Fortress Power eFlex MAX 5.4kWh 

Discover the power and flexibility of the eFlex MAX 5.4 LFP Battery, designed to provide you uninterrupted power in the most demanding environments and weather conditions. This top-tier lithium battery combines advanced technology with practical design to meet a wide range of energy needs while ensuring utmost safety and reliability.

8000 cycles guaranteed, 10-year warranty and the highest quality standard, make it perfect for both your home, apartment and condos, off grid cabins, RVs, boats and more.


Robust Design with Salt Water-resistant Aluminum Enclosure – designed for both indoor and outdoor use without extra protective structures.

Longest Battery Life Span (8000+ cycles; 10+ year) – The patented 3/4″ aluminum enclosure design regulates the battery’s internal temperature high-power applications, resulting in 3 times greater thermal performance than competitors and extended life span.

99% Efficiency with 2W Idle Power – Enhanced Performance in Off-Grid Systems with 2W consumption, minimizing power loss in standby mode and resulting in cost savings.

Easy to Scale-up Battery Capacity to Match Your Energy Need – included Busbars enable faster installation of multiple units in parallel with fewer errors, handle higher power current than battery cables.

Clean, Streamlined and flexible Installation The waterproof front battery cover eliminates the extra wire management (such as conduits). Both Wall mount and floor mount are available.

Best Bang for Your Buck – Obtain lowest energy cost with best battery technology and product quality, highest performance and affordable price point.

 

eFlex MAX Datasheet

eFlex MAX Owner / Installation Manual

eFlex MAX Warranty Letter

Why Choose Green Vista Living


At Green Vista Living, we’re passionate about providing top-quality renewable energy and eco-friendly products that not only enhance your life but also help protect the planet. We’ve built our business with one mission in mind: to be the go-to destination for renewable energy solutions, outdoor gear, and off-grid supplies. When you shop with us, you’re not just getting innovative products—you’re joining a community that’s committed to sustainability.

We Put Our Customers First


As a small, dedicated team, we care deeply about your experience. Unlike large, faceless online companies, Green Vista Living offers a personal touch in everything we do. We're here for you from start to finish—whether you need product advice, support after a purchase, or just have questions. Our knowledgeable customer service team is always just a phone call or email away, ready to assist you in any way possible.

We Share Your Passion for the Planet


Our love for the outdoors and sustainable living runs deep. Most of our team hails from the mountains of Colorado, where renewable energy and the environment are part of daily life. So when you call Green Vista Living, you’ll speak directly with an expert who understands both the technical side of renewable products and the lifestyle they support. Whether you’re looking for solar generators, EV chargers, or any of our eco-friendly offerings, you can trust us to guide you with expertise and passion.

Trusted Industry Experts


Our close partnerships with the best brands in renewable energy and outdoor gear give us insider knowledge that you won’t find anywhere else. We’ve taken the time to carefully select products that stand out for their quality and reliability. At Green Vista Living, we believe in understanding our products inside and out so that we can help you make the right choice with confidence.

More Reasons to Love Green Vista Living


Price Match Guarantee: Thanks to our partnerships, we offer the best prices around. If you find a better deal, we’ll refund the difference.


Free Shipping: We offer free shipping on most orders to the lower 48 U.S. states, making your shopping experience even easier.


100% Secure Ordering: Our site uses SSL Encryption technology to keep your payment and personal information safe and secure.


Volume Discounts: For large orders, we’re happy to provide special pricing—just reach out for a custom quote.


Authorized Dealer: As an authorized dealer for all our brands, you’ll receive full manufacturer warranties with every order.


At Green Vista Living, we aim to make your renewable energy and outdoor experience as seamless and enjoyable as possible. With our unmatched customer service, expertise, and dedication to quality, you can shop with confidence, knowing you’re supporting a company that’s as committed to the planet as you are.

Frequently Asked Questions

Yes! We provide free and fast shipping on MOST orders within the continental United States. However, some specific brands and items will require a quote. You can live chat or call us for a quote
Most orders ship out within 1–2 business days and arrive within 3–5 business days depending on your location.
We offer easy returns as long as your item meets the conditions outlined in our Return Policy. Items must be unused, in original packaging, and returned within the specified return window.
Absolutely! Our in-house product experts are here to help. Live chat or call us 513-743-829 for personalized advice before or after your purchase.
Yes. All products include any applicable manufacturer warranties, and we’ll help you handle any warranty claims if needed.
Yes, we only sell 100% authentic, brand-new products, sourced directly from our manufacturers or authorized distributors.

Over 2,000+ Online Orders

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Feedback From Our Customers

At Green Vista Living, we pride ourselves on delivering top-quality products and exceptional service to solar professionals and homeowners alike. Here's what our customers have to say about their experiences with us.

Kevin Leary
May 18, 2025
★★★★★

Incredible Tech Support from Anees of Green Vista Living. Exceptional service and went above and beyond on every question.

Bryan Cunningham
Off grid Kit • Dec 21, 2025
★★★★★

Shipment was slow due to high demand, but the team kept me informed and ensured everything arrived properly.

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