$2,238.32
Fox EQ4800 4.66kWh HV Battery Slave—
$2,238.32
The Story
The Fox EQ4800 4.66 kWh High Voltage Battery Slave (FE-HV-EQS-4800 / EQS4800) is the expansion module for Fox EQ4800 high-voltage battery stacks, and the direct replacement for the EC4800 Slave. Each module adds 4.66 kWh of fully usable storage capacity at 100% depth of discharge — making the EQ4800 Slave more energy-dense than the 90% DoD ECS4300 series. A single stack supports up to 8 Slave modules alongside one EQM4800 Master, giving a total maximum of 41.93 kWh per stack. The EQS4800 is also backwards-compatible with existing EC4800 Master systems (maximum 7 modules total when mixing generations).
4.66 kWh
Per module
100% DoD
Fully usable
>95%
Round-trip efficiency
8 max
Slaves per stack
IP65
Indoor / outdoor
⚠ Installer Note — Must be installed by a qualified electrician or MCS-accredited installer. High-voltage DC battery system. Register the install on the Fox ESS portal for full warranty activation.
⚡ Important — Slave cannot operate alone — This module requires a Fox EQ4800 Master (FE-HV-EQM-4800) or compatible EC4800 Master to operate. Maximum 9 modules per stack with EQM4800 (41.93 kWh); maximum 7 modules when mixed with EC4800 generation. EQ4800 Slaves are also compatible with existing EC4800 Master stacks.
Features & Benefits
✔ 100% DoD — No Wasted Capacity
Every kWh of nominal capacity is usable. At 100% depth of discharge, the EQ4800 Slave delivers the full 4.66 kWh per module — compared to approximately 3.73 kWh from a 4.14 kWh ECS4300 module at 90% DoD. This means fewer modules are needed for a given usable capacity target.
✔ Upgrade Path for EC4800 Systems
EQS4800 Slaves are backwards-compatible with existing EC4800 Master (ECM4800) stacks — if you need to expand an existing system and ECS4800 Slaves are unavailable, EQS4800 modules can be added directly. Mixed stacks are limited to 7 modules total.
✔ Scalable Post-Installation
Add Slave modules at any time without disrupting the existing system — up to a maximum of 8 Slaves per EQM4800 Master (41.93 kWh total). The plug-and-play buckle-fix design makes on-site expansion straightforward.
✔ LFP — Safest Lithium Chemistry
LiFePO₄ cells have no thermal runaway risk and ≥6,000 cycle life — over 16 years of daily cycling. Superior safety and longevity versus NMC-based battery systems commonly used in lower-cost alternatives.
✔ High Efficiency, High Voltage
High-voltage DC architecture reduces current and resistive losses through cabling, achieving >95% round-trip efficiency — more of what is stored actually comes back out as usable electricity.
✔ IP65 for Flexible Siting
IP65-rated for both indoor and outdoor installation (stand-mounted). Natural convection cooling — no fans, no noise, no moving parts. Suitable for garages, utility rooms, and sheltered outdoor locations.
Technical Specifications
| Part Number (Slave) | FE-HV-EQS-4800 / EQS4800 |
| Module Type | Slave (requires EQM4800 or ECM4800 Master) |
| Battery Chemistry | LFP (LiFePO₄) |
| Nominal Energy per Module | 4.66 kWh |
| Depth of Discharge | 100% |
| Round-Trip Efficiency | >95% |
| Cycle Life | ≥6,000 cycles |
| Normal Capacity | 104 Ah |
| Recommended Charge/Discharge Current | 30 A |
| Max Charge/Discharge Current | 50 A |
| Peak Discharge Current (60 s) | 65 A |
| Communication | CAN (daisy-chain via Master) |
| Max Slaves per Stack (EQM4800) | 8 (max stack: 41.93 kWh) |
| Max Modules (mixed EC4800 stack) | 7 total |
| Operating Temperature — Discharge | –10°C to +55°C |
| Operating Temperature — Charge | 0°C to +55°C |
| Ingress Protection | IP65 |
| Certifications | IEC 62619, EN IEC 61000-6-1/2/3/4, UN38.3 |
| Warranty | 10×3 years (see Fox ESS Battery Warranty Terms) |
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Description
The Fox EQ4800 4.66 kWh High Voltage Battery Slave (FE-HV-EQS-4800 / EQS4800) is the expansion module for Fox EQ4800 high-voltage battery stacks, and the direct replacement for the EC4800 Slave. Each module adds 4.66 kWh of fully usable storage capacity at 100% depth of discharge — making the EQ4800 Slave more energy-dense than the 90% DoD ECS4300 series. A single stack supports up to 8 Slave modules alongside one EQM4800 Master, giving a total maximum of 41.93 kWh per stack. The EQS4800 is also backwards-compatible with existing EC4800 Master systems (maximum 7 modules total when mixing generations).
4.66 kWh
Per module
100% DoD
Fully usable
>95%
Round-trip efficiency
8 max
Slaves per stack
IP65
Indoor / outdoor
⚠ Installer Note — Must be installed by a qualified electrician or MCS-accredited installer. High-voltage DC battery system. Register the install on the Fox ESS portal for full warranty activation.
⚡ Important — Slave cannot operate alone — This module requires a Fox EQ4800 Master (FE-HV-EQM-4800) or compatible EC4800 Master to operate. Maximum 9 modules per stack with EQM4800 (41.93 kWh); maximum 7 modules when mixed with EC4800 generation. EQ4800 Slaves are also compatible with existing EC4800 Master stacks.
Features & Benefits
✔ 100% DoD — No Wasted Capacity
Every kWh of nominal capacity is usable. At 100% depth of discharge, the EQ4800 Slave delivers the full 4.66 kWh per module — compared to approximately 3.73 kWh from a 4.14 kWh ECS4300 module at 90% DoD. This means fewer modules are needed for a given usable capacity target.
✔ Upgrade Path for EC4800 Systems
EQS4800 Slaves are backwards-compatible with existing EC4800 Master (ECM4800) stacks — if you need to expand an existing system and ECS4800 Slaves are unavailable, EQS4800 modules can be added directly. Mixed stacks are limited to 7 modules total.
✔ Scalable Post-Installation
Add Slave modules at any time without disrupting the existing system — up to a maximum of 8 Slaves per EQM4800 Master (41.93 kWh total). The plug-and-play buckle-fix design makes on-site expansion straightforward.
✔ LFP — Safest Lithium Chemistry
LiFePO₄ cells have no thermal runaway risk and ≥6,000 cycle life — over 16 years of daily cycling. Superior safety and longevity versus NMC-based battery systems commonly used in lower-cost alternatives.
✔ High Efficiency, High Voltage
High-voltage DC architecture reduces current and resistive losses through cabling, achieving >95% round-trip efficiency — more of what is stored actually comes back out as usable electricity.
✔ IP65 for Flexible Siting
IP65-rated for both indoor and outdoor installation (stand-mounted). Natural convection cooling — no fans, no noise, no moving parts. Suitable for garages, utility rooms, and sheltered outdoor locations.
Technical Specifications
| Part Number (Slave) | FE-HV-EQS-4800 / EQS4800 |
| Module Type | Slave (requires EQM4800 or ECM4800 Master) |
| Battery Chemistry | LFP (LiFePO₄) |
| Nominal Energy per Module | 4.66 kWh |
| Depth of Discharge | 100% |
| Round-Trip Efficiency | >95% |
| Cycle Life | ≥6,000 cycles |
| Normal Capacity | 104 Ah |
| Recommended Charge/Discharge Current | 30 A |
| Max Charge/Discharge Current | 50 A |
| Peak Discharge Current (60 s) | 65 A |
| Communication | CAN (daisy-chain via Master) |
| Max Slaves per Stack (EQM4800) | 8 (max stack: 41.93 kWh) |
| Max Modules (mixed EC4800 stack) | 7 total |
| Operating Temperature — Discharge | –10°C to +55°C |
| Operating Temperature — Charge | 0°C to +55°C |
| Ingress Protection | IP65 |
| Certifications | IEC 62619, EN IEC 61000-6-1/2/3/4, UN38.3 |
| Warranty | 10×3 years (see Fox ESS Battery Warranty Terms) |
