Fox ESS H1-3.7-E-G2 3.7 kW Single-Phase Hybrid Solar Inverter

The Fox ESS H1-3.7-E-G2 Hybrid Solar Inverter is a professional-grade 3.7 kW single-phase inverter designed for UK homes and light-commercial systems seeking a dependable, high-efficiency solution for solar and battery integration.

High-efficiency 3.7 kW solar inverter for advanced UK systems

Part of the proven Fox ESS H1 Series, the H1-3.7-E-G2 builds on the reliability of the earlier generation while offering improved MPPT performance and enhanced hybrid control logic. It supports a maximum PV input power of 5,500 W and operates across a wide 80–550 V MPPT range — ideal for installations with mixed panel orientations or partial shading. Featuring dual independent MPPT trackers and an impressive 97.08 % conversion efficiency, it ensures optimal power harvest throughout varying UK light conditions.

This model sits below the Fox ESS H1-5.0-E-G2, making it perfect for mid-sized domestic systems that demand robust, battery-ready capability without oversizing. The integrated high-voltage DC coupling design minimises conversion loss, ensuring clean, stable AC output and efficient storage management when paired with Fox ESS LFP battery modules.

Engineered for performance and protection

Every Fox ESS inverter is built to deliver exceptional reliability under UK operating conditions. The H1-3.7-E-G2 incorporates residual current and insulation monitoring, reverse-polarity and anti-islanding protection, plus built-in surge protection (Type II DC / Type III AC). Its natural cooling design keeps noise levels below 15 dB, and the IP65-rated enclosure allows outdoor installation without compromise.

• Up to 97.08 % peak efficiency with 99 % MPPT tracking accuracy
• Dual MPPT design for independent string optimisation
• IP65 weatherproof rating with natural cooling
• Wi-Fi, LAN, and optional 4G remote monitoring via FoxCloud

If you’re wondering how efficient the H1-3.7-E-G2 is under British conditions, its stable performance curve and broad voltage tolerance (80–550 V) allow maximum yield even during cloudy or low-irradiance periods — an important advantage for northern-facing or multi-aspect arrays.

Specification data derived from Fox ESS H1/AC1 G2 official documentation (Version 1.4, September 2023).

Why we recommend the Fox ESS H1-3.7-E-G2 Hybrid Inverter

At Evergy, we recommend the Fox ESS H1-3.7-E-G2 for its robust design, exceptional conversion efficiency, and intelligent hybrid functionality tailored for British homes. Its dual MPPT structure, IP65 enclosure, and advanced safety protection make it one of the most installer-friendly inverters in its class. The G2 generation also benefits from enhanced firmware stability and improved communication protocols, ensuring seamless integration with Fox’s latest high-voltage LFP battery systems.

Unlike many budget inverters on the market, Fox ESS products are backed by strong UK warranty support, a proven global R&D foundation, and verified compliance with G99 and EN 62109 standards. This combination of build quality, protection features, and efficient energy management makes the H1-3.7-E-G2 a dependable long-term investment for residential and light-commercial systems alike.

Evergy is the renewable division of LAMPS Electrical — an independent UK wholesaler with over 15 years of trade experience supplying installers nationwide. Our product recommendations are based on direct feedback from professionals and verified performance data, ensuring every inverter we supply meets real-world installer expectations.

Choose the Fox ESS H1-3.7-E-G2 for premium build quality, proven UK reliability, and smart hybrid capability that evolves with your energy needs.

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