Fox ESS CQ7 7.02kWh Slave Battery – CQ7-S

Expand a high-performance Fox ESS CQ7 battery system with the Fox ESS CQ7 7.02kWh Slave Battery. Designed for compatible Fox ESS high-voltage hybrid and AC-coupled inverters, the CQ7 uses safe lithium iron phosphate (LiFePO₄) battery chemistry in a modular, floor-standing design.

Each CQ7-S Slave battery adds 7.02kWh nominal capacity to a compatible CQ7 stack. The Slave does not contain the system controller / BMS and must operate under a CQ7-M Master battery.

Important: The CQ7-S Slave battery cannot operate on its own. Every CQ7 stack requires exactly 1x CQ7-M Master battery, with the supported number of CQ7-S Slave batteries added in series.

Compatibility: CQ7 system size depends on the connected Fox ESS inverter. Always check the exact inverter model, firmware and current Fox ESS compatibility guidance before ordering.

Included in Kit

• 1x Fox ESS CQ7 7.02kWh Slave Battery

Not included: This product does not include the CQ7-M Master battery or its integrated system controller / BMS. A Master is required in every CQ7 stack.

Starting a new system? Purchase the Fox ESS CQ7 7.02kWh Master Battery HERE.

Fox ESS CQ7 Battery Sizing and Scalability

The minimum and maximum number of CQ7 batteries varies depending on the connected Fox ESS inverter:

How the stacks are built: Every stack requires 1x CQ7-M Master battery, with CQ7-S Slave batteries added to reach the required stack size. Therefore, a two-battery stack contains 1x Master and 1x Slave; a three-battery stack contains 1x Master and 2x Slaves; and a four-battery stack contains 1x Master and 3x Slaves.

Multiple stacks: H3 Pro can support up to two stacks and H3 Plus can support up to three. Each separate stack requires its own Master battery. Larger stacks may require the optional Fox ESS base to split the modules into two columns.

Key Features of the Fox ESS CQ7 Slave Battery

• 7.02kWh nominal capacity per battery module
• Adds storage capacity to a compatible CQ7 battery stack
• Operates under the CQ7-M Master battery and its integrated system controller / BMS
• High-voltage LiFePO₄ chemistry for a safe and efficient storage solution
• 90% Depth of Discharge, providing approximately 6.32kWh usable capacity per module
• Scalable design with up to 14 modules connected in series, subject to inverter limits
• More than 95% battery pack round-trip efficiency under stated test conditions
• 80A maximum charge / discharge current
• 110A peak discharge current for 60 seconds
• IP65 rated for indoor or outdoor floor-standing installation
• Internal battery heating in every module for improved cold-weather operation
• Integrated aerosol fire protection function
• Natural convection cooling with no cooling fan required
• CAN communication within a compatible Fox ESS CQ7 system
• 12-year manufacturer warranty, subject to Fox ESS warranty terms

Capacity and Electrical Specifications

• Nominal Capacity: 7.02kWh per module
• Approximate Usable Capacity: 6.32kWh per module at 90% DoD
• Nominal Voltage: 57.6V per module
• Battery Voltage Range: 52.2-65.7V per module
• Recommended Charge / Discharge Current: 50A
• Maximum Charge / Discharge Current: 80A
• Peak Discharge Current: 110A for 60 seconds
• Battery Pack Round-Trip Efficiency: More than 95% at 25°C and 0.3C charge / discharge
• Depth of Discharge: 90%
• Communication: CAN

Physical Specifications

• Slave Module Dimensions (W x D x H): 660 x 360 x 190mm
• Slave Module Weight: Approximately 50kg (±5%)
• Minimum Two-Module System Dimensions (W x D x H): 660 x 360 x 420mm
• Minimum Two-Module System Weight: Approximately 105.5kg (±5%)
• Installation: Indoor or outdoor, floor-standing
• Ingress Protection: IP65
• Cooling: Natural convection

Operating Conditions

• Standard Charging Temperature: 0°C to 55°C
• Standard Discharging Temperature: -10°C to 55°C
• With Battery Heating Enabled: Charging and discharging from -25°C to 55°C
• Storage Temperature: -10°C to 50°C
• Humidity: 5-95%, non-condensing
• Maximum Altitude: 3,000m

Safety and Certification

• Battery Chemistry: Lithium iron phosphate (LiFePO₄)
• Fire Protection: Integrated aerosol fire protection function
• Safety: IEC 62619
• EMC: IEC 61000-6-1/2/3/4
• Transport: UN38.3
• Ingress Protection: IP65

Installation and Monitoring

• The CQ7-S Slave battery must be connected within a stack containing exactly 1x CQ7-M Master battery
• Slave batteries are connected in series to increase the voltage and storage capacity of the complete CQ7 system
• The plug-and-play modular design helps simplify installation and future expansion
• System performance, battery status and energy data can be monitored through FoxCloud when connected to a compatible Fox ESS inverter
• Installation and commissioning must be completed by a suitably qualified installer in accordance with Fox ESS instructions

Expanding an existing system: Fox ESS requires the state of charge of existing and newly added batteries to be closely matched. The manual specifies a maximum SOC difference of ±5% and advises that the manufacture date of an added battery should not exceed 12 months. Confirm expansion suitability before ordering.

Fox ESS CQ7 Warranty

The Fox ESS CQ7 battery range includes a 12-year manufacturer warranty, subject to the current Fox ESS warranty terms, correct system design, professional installation and any applicable commissioning or registration requirements.

Compatibility

The CQ7 is designed for use with selected Fox ESS high-voltage inverter ranges, including:

• Fox ESS H1-G2 / AC1-G2
• Fox ESS KH Series
• Fox ESS H3 Smart
• Fox ESS H3 Pro
• Fox ESS H3 Plus

Important: Compatibility and the permitted number of batteries vary between inverter models. Do not mix CQ7 modules with other Fox ESS battery models in the same stack. Please contact us before ordering if you are expanding an existing system or are unsure which configuration you require.

Frequently Asked Questions

Fox ESS Integrations

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Product Code: CQ7-S
Learn More: Fox ESS CQ7 Battery

Downloads

Datasheet – Fox ESS CQ7
User Manual – Fox ESS CQ7

Video

Order the Fox ESS CQ7 7.02kWh Slave Battery today from The Eco Supermarket for fast UK delivery, expert technical support and full manufacturer warranty.