Fox ESS S22 All-in-One Battery Storage System (800W / 2.1kWh)

The Fox ESS S22 is a compact, all-in-one battery storage system designed for smaller residential solar installs. With 800W rated power and 2.11kWh usable storage, it delivers reliable backup and day-to-day savings — without the complexity of separate components. Installation is fast and fuss-free, making it a favourite among UK installers looking to streamline smaller PV setups.

Why Choose This Product?

• All-in-one simplicity: Built-in inverter, battery, and safety protections in a single unit
• High usable capacity: 90% DoD for dependable daily cycling
• EPS backup: Optional emergency power supply keeps key circuits running during outages
• Weather-ready: IP65 rating and integrated heating for outdoor or cold-climate installs
• Quick install: Floor-mounted, plug-and-play with minimal wiring
• Smart monitoring: Connects to FoxCloud V2.0 and smartphone app for full system visibility
• Stackable: Expand storage up to 8.44kWh with additional S22 modules

Performance and Design

The S22 delivers 800W continuous power with a peak output of 1.2kVA, making it well suited for lighting, routers, fridges, and other priority loads. The system uses lithium iron phosphate (LiFePO₄) chemistry for safety and long-term reliability, with a lifespan of over 6,000 cycles at 90% depth of discharge. Thanks to its compact footprint and minimalist design, it fits neatly into tight spaces — ideal for UK homes with limited utility areas.

Monitoring and Connectivity

Fox ESS includes full cloud-based monitoring via the FoxCloud V2.0 portal, plus Bluetooth, Wi-Fi, LAN and RS485 interfaces for local access. Homeowners and installers can track performance, alerts and SOC (state of charge) from a smartphone or PC. Built-in OLED display and battery LED indicators give quick visual feedback on status and alarms.

Who is it for?

• Domestic retrofits: Homeowners looking to add basic storage to an existing solar array
• Small new-builds: Developers and architects working with compact sites or flats
• Installers: Professionals needing a low-hassle, all-in-one system for quick installs

Technical Specifications

Each unit supports up to 4 stackable batteries (8.44kWh total).