Going off-grid used to mean giving up on-grid level safety and compliance. Not anymore. With the rise of wildfires, battery recalls, and stricter permitting rules, homeowners and installers are prioritizing certified safety in off-grid power systems. EG4 is meeting that demand head-on—offering the only UL 9540 certified off-grid energy storage system (ESS) on the market. 

Backed by rigorous UL 9540 and UL 9540A testing, EG4’s off-grid ESS brings certified fire safety, thermal protection, and real-world reliability into one accessible, scalable package. Whether you’re a homeowner seeking true energy independence or an installer looking for AHJ-friendly options, EG4 ensures going off-grid never means going unprotected. 

Please note: The EG4 12000XP and EG4 6000XP off-grid inverters are only certified to UL 9540 when paired with the EG4 WallMount 280Ah Indoor Battery. 

What Is UL 9540 and UL 9540A—and Why Do They Matter? 

UL 9540: The Gold Standard for Energy Storage Safety 

UL 9540 is the North American Standard for Safety for Energy Storage Systems (ESS), covering complete systems that include the inverter, battery, battery management system (BMS), thermal controls, and related equipment. 

To pass UL 9540, the entire ESS must demonstrate: 

• Electrical safety 

• Mechanical integrity 

• Fire risk mitigation 

• System-level performance under stress 

UL 9540A: Fire Propagation Testing 

UL 9540A is a method used to evaluate how an energy storage system behaves in a thermal runaway event—the most severe type of battery failure. This test helps determine: 

• Whether fire or gas propagation occurs between battery cells or units 

• How well the system contains or limits that propagation 

• What kind of safety spacing or enclosures are needed 

For off-grid homes, where utility fire protection or remote monitoring may not be available, these tests are critical. UL 9540A proves how the system performs when things go wrong. 

To better understand the differences between UL 9540 and UL 9540A, check out our white paper, Understanding UL 9540 & 9540A – Key Differences, or review this informational bulletin from SEAC. 

Why UL Certification Is Critical for Off‑Grid Systems 

Homeowners and installers often ask: “If I’m not tied to the grid, why should I care about grid-level certification?” The answer is simple, safety doesn’t stop at the grid edge. 

Whether you’re in the remote hills of Appalachia, coastal New England, rural Texas, off-grid California, or mountainous Colorado, energy storage system failures can be catastrophic. Without third-party safety validation, you’re relying solely on manufacturer claims. That’s not good enough anymore. 

Here’s what UL 9540 certification provides in off-grid environments: 

• Fire protection by design 

• Permitting ease with local Authorities Having Jurisdiction (AHJs) 

• Insurance support and reduced liability risks 

• Confidence for both installers and homeowners 

EG4 is the only brand offering UL 9540 certified off-grid ESS—making it the clear leader in this critical safety category. 

Certified Safety. True Off-Grid. 

Unlike many inverter or battery manufacturers that only certify components individually, EG4 certifies the entire off-grid system, including: 

• Inverter (EG4 12000XP & EG4 6000XP) 

• Battery (EG4 WallMount 280Ah Indoor Battery) 

• BMS and thermal integration 

• System configuration and wiring practices 

System-Level Certification Advantages 

• UL 9540 and UL 9540A tested for thermal propagation and fire control 

• Easy to scale with modular configurations 

• Engineered for residential install environments, both indoor and outdoor 

• Documentation for UL listings to present to AHJs and inspectors 

EG4’s off-grid ESS isn’t just safer, it’s also more practical. With U.S.-based technical support and a growing national installer network, it’s a solution made for real homes, not just lab demonstrations. 

A Smarter Choice for Homeowners 

For homeowners living off the grid or planning to, EG4’s UL‑certified system delivers peace of mind without sacrificing energy independence. 

Why Homeowners Choose EG4: 

• Certified fire safety for rural or remote homes 

• Built to simplify inspections and approvals 

• Designed with insurance compliance in mind 

• Confidence in long-term reliability 

• Lower lifetime system cost due to fewer retrofits or failures 

And with scalable designs, EG4 systems grow with your needs—whether you’re powering a small cabin or a full home with HVAC, well pumps, and EV charging. 

Important: Energy storage systems must be properly sized to support the intended loads. For example, the EG4 6000XP and 12000XP models have different capabilities depending on system configuration and usage. For detailed sizing guidance, contact EG4 Support or refer to product specifications. 

A Powerful Advantage for Installers & AHJs 

For Installers and EPCs: 

• Simplify permitting and approvals with certification documentation 

• Differentiate your offering from lower-cost but uncertified competitors 

• Reduce callbacks, warranty disputes, and liability exposure 

• Work with systems that are backed by U.S.-based support 

• Build your reputation by installing code-compliant, safe systems 

Disclaimer: EG4 Electronics LLC makes no representations, promises, or guarantees regarding inspection outcomes or approvals from Authority Having Jurisdiction (AHJ). It is the sole responsibility of the customer to consult with their local inspector or AHJ prior to purchasing or installing any equipment to ensure compliance with applicable codes and regulations. 

For AHJs and Fire Inspectors: 

• UL 9540A documentation allows for objective evaluation 

• Minimizes back-and-forth with installers 

• Demonstrates the system meets national fire and safety codes 

• Provides assurance of fire containment and thermal management 

EG4 gives inspectors what they need to feel confident approving off-grid installations. 

Common User Questions and Concerns 

Is UL 9540 certification required for off-grid systems? 

Not always, but it is increasingly preferred by AHJs across the U.S., especially in fire-prone states like California or areas with strict permitting like Colorado and Florida. Even where not required, UL certification can simplify inspections and insurance. 

What’s the difference between UL 9540 and UL 9540A? 

UL 9540 certifies the overall safety of the ESS as a system. UL 9540A tests how the system handles thermal runaway and whether fire propagates across battery cells or units. Both are needed to meet the highest safety standards. 

Can I expand my EG4 UL-certified system later? 

Yes. EG4’s off-grid ESS is modular and expandable, but to maintain UL 9540 status, expansion must follow EG4’s certified configurations. Check with your installer or EG4 support before modifying. 

What if my inspector isn’t familiar with UL 9540? 

Provide them with EG4’s certification documents and system specs. EG4 also offers installer and AHJ support materials to help simplify permitting and code review. 

Does UL certification make the system more expensive? 

Surprisingly, no. EG4 offers UL 9540 certified off-grid systems that are comparable in price to uncertified options—but with added safety, warranty assurance, and installer support. 

Certified Safety That Doesn’t Stop at the Grid 

For too long, off-grid homeowners had to choose between freedom and safety. EG4 changes that. With the only UL 9540 certified off-grid ESS, EG4 delivers proven fire protection, faster install approval, and unmatched peace of mind—whether you’re installing in wildfire country or a remote off-grid cabin. 

Ready to Go Off-Grid with Certified Safety? 

For Homeowners: 
Don’t compromise when it comes to off-grid power. Get UL-certified safety, reliability, and peace of mind—Get EG4 and take control of your energy future. 

For Installers: 
Stand out with the only UL 9540 certified off-grid ESS on the market. Streamline approvals, reduce liability, and win more jobs—Become a Certified EG4 Installer today.