Fox ESS HV Junction Box – for EP5-H & EP11-H Battery Parallel Setups

Fox ESS HV Junction Box: The Essential Expansion Hub for EP5-H and EP11-H Batteries

When expanding your energy storage system with multiple Fox ESS EP5-H or EP11-H batteries, the HV Junction Box is a crucial component. Designed to safely interconnect up to four high-voltage batteries in parallel, it simplifies installation, supports consistent current flow, and ensures neat, protected wiring , all in a compact, wall-mounted enclosure suitable for indoor or outdoor use.

Expand Your Storage up to 40kWh

The HV Junction Box enables up to four Fox ESS EP series batteries to operate together as a single, cohesive unit. Whether you're adding more capacity to support EV charging, longer off-grid runtimes, or heavier daytime loads, this junction box provides the backbone for safe and scalable system expansion.

• Supports 4 battery inputs and 1 inverter/load output
• Compatible with EP5-H and EP11-H batteries
• Achieve up to 40kWh of usable storage in one installation

Compact, Protected and Installer-Friendly

With dimensions of just 186 × 170 × 78 mm and weighing only 4.5 kg, the HV Junction Box is easy to wall-mount and integrate into both residential and light commercial settings. Its IP65-rated casing allows for installation in utility rooms, garages, or sheltered outdoor areas, while its natural convection cooling means no fans or noise.

• IP65 weatherproof rating for flexible placement
• Natural cooling and silent operation
• Quick-fit design for reduced install time

Safe Parallel Operation for High Voltage Systems

Designed for high-voltage lithium battery systems, the HV Junction Box allows balanced power distribution across up to four batteries. It supports continuous currents of up to 50A (65A peak), ensuring stable output to your Fox ESS inverter even under high demand. The unit is certified to ROHS and REACH standards and operates safely in environments up to 55°C.

• Rated for 50A continuous and 65A peak current
• Operating temperature: –20°C to +55°C
• Certified to meet environmental and safety standards

Why Evergy Recommends This Product

We recommend the HV Junction Box for any customer planning to scale their EP5-H or EP11-H battery storage. It makes system growth simple, tidy, and technically sound , with no need for custom cabling or DIY connections.

• Essential for 2–4 battery EP system configurations
• Designed specifically for EP5-H and EP11-H battery series
• Trusted by installers for ease of use and build quality

Ideal for Modular Battery Storage Systems

This junction box is best suited for households and small businesses with growing solar demands or phased installation plans. It ensures consistent system operation as capacity scales, without overcomplicating wiring or layout.

Key Technical Specifications

• Battery Ports: 4 inputs, 1 output
• Max Continuous Current: 50A
• Dimensions: 186 × 170 × 78 mm
• Weight: 4.5 kg

See datasheet or spec tab for full technical details.

Build the Complete EP Series System

Use the HV Junction Box to expand your EP5-H or EP11-H battery setup alongside Fox ESS hybrid inverters, mounting systems, and optimisers. Learn more about planning storage with our UK battery guide.

FAQs

Q: Do I need a junction box for just one EP battery?
A: No -  the HV Junction Box is only required when connecting two or more EP5-H or EP11-H batteries in parallel.

Q: Can this unit be installed outside?
A: Yes -  it’s IP65-rated and suitable for outdoor use, provided it’s wall-mounted in a sheltered location.