Fox ESS AC1-5.0-E-G2 5kW AC-Coupled Charger Inverter Gen 2 for HV Battery Storage

The Fox ESS AC1-5.0-E-G2 (part number FE-AC1-5.0) is a 5.0 kW AC-coupled charger inverter designed to add high-voltage battery storage to existing solar PV systems or to operate standalone. This is a battery inverter with no DC/PV inputs; it charges and discharges batteries on the AC side, making it suitable for retrofitting storage to any existing PV installation. The AC1 Gen 2 works with Fox ESS high-voltage batteries including the HV2600, Energy Cube, and MIRA HV25 ranges, requiring a BMS and a minimum of two HV2600 batteries. It includes built-in EPS (emergency power supply) for backup operation, a CT clamp in the box, and a WiFi data logging stick for monitoring via the Fox Cloud platform. Up to 10 units can be installed in parallel. IP65 rated for indoor or outdoor wall-mounted installation, it measures 434 x 418 x 185 mm and weighs 22 kg. Available from DECO Group, a UK solar wholesaler for trade installers.

Key Technical Details

• Part number: FE-AC1-5.0
• Supplier part number: AC1-5.0 (with EPS)
• Model: AC1-5.0-E-G2
• Product type: AC-coupled charger inverter (no DC/PV inputs)
• Topology: Non-isolated

AC Output (Grid)

• Rated AC output power: 5,000 W
• Maximum AC output apparent power: 5,500 VA
• Rated output current (per phase): 22.7 A
• Maximum output current: 25.0 A
• Rated grid voltage: 220 / 230 / 240 V
• Rated grid frequency: 50 / 60 Hz
• Power factor: 1 (adjustable from 0.8 leading to 0.8 lagging)
• Total harmonic distortion (THDi): less than 2% at rated power

AC Input

• Maximum AC input power: 7,500 VA

Battery

• Battery type: Lithium battery (LFP)
• Battery voltage range: 80 V to 480 V
• Maximum charge/discharge current: 40 A
• Battery communication: CAN (communicate with inverter, upgrade BMS)

EPS (Emergency Power Supply)

• EPS rated output power: 5,000 W
• EPS maximum apparent power: 6,000 VA
• EPS maximum current (per phase): 22.7 A
• EPS rated voltage: 220 / 230 / 240 V
• EPS rated frequency: 50 / 60 Hz
• EPS power factor: 1 (adjustable from 0.8 leading to 0.8 lagging)
• EPS THDv (linear load): less than 3% at rated power
• EPS switch time: less than 20 ms
• Parallel operation: up to 10 units

Efficiency

• Maximum efficiency: 97.08%
• Euro efficiency: 96.30%
• Maximum battery discharge efficiency (battery to AC, at full load): 97.00%

General

• Cooling: Natural convection (fanless)
• Noise emission: 35 dB
• Ingress protection: IP65
• Operating temperature range: -25°C to 60°C
• Humidity: 0% to 100% (no condensation)
• Maximum operating altitude: 2,000 m
• Standby consumption: less than 15 W
• Surge protection: DC Type II / AC Type III
• AFCI: Yes
• DC switch: Yes
• Communication: RS485, DRM, Ripple Control, USB, CAN
• Monitoring module: WiFi (included); LAN and 4G optional
• Display: LCD, app, website
• Installation: Wall-mounted
• Dimensions: 434 x 418 x 185 mm (W x H x D)
• Weight: 22 kg

Key Features

• AC-coupled design adds battery storage to existing PV systems without changing the solar inverter
• 5.0 kW rated output with built-in EPS for backup power during grid outages (less than 20 ms switch time)
• 97.08% maximum efficiency with 97.00% battery discharge efficiency
• High-voltage battery platform supporting Fox HV2600, Energy Cube, and MIRA HV25 batteries
• Up to 10 inverters can be installed in parallel, each with a full battery stack
• Integrated DC switch, AFCI, and surge protection (DC Type II / AC Type III)
• CT clamp and WiFi data logging stick included in the box
• IP65 rated for indoor or outdoor wall-mounted installation
• Fanless natural convection cooling at 35 dB

System Compatibility

• Compatible with Fox ESS HV2600 high-voltage batteries (BMS required, minimum 2 batteries per stack)
• Compatible with Fox ESS Energy Cube batteries
• Compatible with Fox ESS MIRA HV25 batteries
• Master and Slave battery modules must be the same size within a stack
• Up to 10 x AC1 inverters in parallel, each with a full battery stack
• A second CT clamp is required if a second generator is present (e.g. PV, wind, or other)

Installation Notes

• Wall-mounted on a solid, non-combustible surface with adequate clearance for airflow and cable routing
• At 22 kg, a two-person lift is recommended
• CT clamp must be fitted on the correct conductor with correct orientation for accurate grid sensing
• BMS plus a minimum of 2 x HV2600 batteries required to form a working stack
• When installing batteries side by side rather than stacked, the longer cable pack FE-HV2600-EXT-1M is recommended
• EPS backup circuit must be wired exactly as specified with correct isolation and protective devices
• Qualified installer only; all work must follow local wiring regulations and Fox ESS documentation

Included Components

• 1 x Fox ESS AC1-5.0-E-G2 charger inverter
• 1 x CT clamp for import/export sensing
• 1 x Fox WiFi data logging stick

Certifications and Compliance

• EN 62109-1, EN 62109-2 (Safety)
• G98
• G99
• EN 50549

Warranty

• Standard warranty: 5 years
• Extended warranty: 10 years when the installation is registered with Fox ESS online

Common Questions

Click a question below to reveal the answer.

What does "AC-coupled" mean?

The AC1 charges and discharges batteries on the AC side of the system. It has no DC/PV inputs. This makes it ideal for adding battery storage to an existing solar PV installation without changing the existing PV inverter.

What batteries are compatible with the Fox ESS AC1 5.0kW Gen 2?

The AC1 Gen 2 works with Fox ESS high-voltage batteries including the HV2600, Energy Cube, and MIRA HV25 ranges. A BMS unit is required and a minimum of 2 x HV2600 batteries are needed to form a working stack. Master and Slave modules must be the same size.

How many Fox ESS AC1 inverters can be installed in parallel?

Up to 10 AC1 inverters can be installed in parallel, each with a full battery stack connected. This enables scalable storage for larger residential or commercial projects.

Does the Fox ESS AC1 5.0kW Gen 2 support backup power?

Yes. The AC1 Gen 2 has built-in EPS (emergency power supply) with a rated output of 5,000 W and a grid-to-backup switch time of less than 20 ms.

What is included in the box with the Fox ESS AC1 5.0kW Gen 2?

The box includes the AC1-5.0-E-G2 charger inverter, a CT clamp for import/export sensing, and a Fox WiFi data logging stick for monitoring via Fox Cloud.

What are the dimensions and weight of the Fox ESS AC1 5.0kW Gen 2?

The AC1 5.0kW Gen 2 measures 434 x 418 x 185 mm (W x H x D) and weighs 22 kg. It is wall-mounted; a two-person lift is recommended.

DECO Group supplies Fox ESS AC-coupled charger inverters across the full 3.0 kW to 6.0 kW range alongside HV2600 batteries, BMS controllers, Energy Cube modules, wall-mount brackets, extension cables, and monitoring accessories. Browse our Fox ESS storage catalogue for complete AC-coupled battery retrofit system components.

About DECO Group

We supply Fox ESS AC-coupled charger inverters, high-voltage battery modules, and all associated system components to professional installers and electrical contractors across the UK. Our AC1 Gen 2 range is stocked in all wattage variants with batteries, BMS units, and installation hardware available for complete system builds. Visit decogroup.co.uk for the full catalogue.