The Fox EQ4800 4.66 kWh High Voltage Battery Master (FE-HV-EQM-4800 / EQM4800) is the next-generation Master module for Fox ESS high-voltage battery stacks, and the direct replacement for the ECM4800. Like its predecessor, it contains the Battery Management System and serves as the communications hub for the stack — but the EQ4800 upgrades the DoD to 100% depth of discharge, delivering fully usable stored energy and a larger maximum stack capacity of 41.93 kWh (1 Master + 8 Slaves). Built on LFP (LiFePO₄) chemistry, it achieves >95% round-trip efficiency and ≥6,000 cycle life, with IP65 protection for indoor or outdoor installation. EQ4800 Slave modules (FE-HV-EQS-4800) can also be mixed with legacy EC4800 systems (maximum 7 modules when mixed).
NEW 100% DoD
Full capacity usable
>95%
Round-trip efficiency
41.93 kWh
Max stack capacity
⚠ 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 to activate the full warranty terms.
⚡ System Requirements & Compatibility — A minimum of 1× EQM4800 Master + 1× EQS4800 Slave is required. Maximum 9 modules per stack (1 Master + 8 Slaves). The EQ4800 is the direct replacement for the ECM4800 — same specification, updated firmware. EQ4800 Slave modules can be mixed with legacy EC4800 systems (limited to 7 total modules when mixed). Compatible with Fox H1, KH1, and AIO hybrid inverter ranges.
Features & Benefits
✔ 100% Depth of Discharge
Unlike the ECS4300 series (90% DoD), the EQ4800 delivers 100% usable capacity — meaning the full 4.66 kWh per module is available to the system. This is a meaningful improvement in effective storage per module with no additional cost.
✔ Larger Maximum Capacity
The EQ4800 supports up to 9 modules per stack (1 Master + 8 Slaves), enabling a total storage capacity of 41.93 kWh — significantly more than the ECS4300's 29.03 kWh maximum, making it suitable for larger homes and commercial applications.
✔ ECM4800 Drop-In Replacement
The EQ4800 is physically and electrically identical to the ECM4800 — same dimensions, same connectors, same performance specs — just with updated firmware. Installers familiar with the ECM4800 series will find installation identical.
✔ Integrated BMS
The Master contains the full Battery Management System — cell balancing, state-of-charge monitoring, over/under voltage and current protection, and temperature management — managed across all connected Slave modules automatically.
✔ LFP Chemistry — Safe & Long-Lived
LiFePO₄ cells deliver ≥6,000 cycles with intrinsic thermal stability and no thermal runaway risk. At one full cycle per day, this equates to over 16 years of operation — well beyond typical solar system lifetimes.
✔ IP65, Indoor or Outdoor
IP65 dust and jet-water protection supports garage, plant room, or sheltered outdoor installation. Natural convection cooling — fanless and silent. Wide operating temperature range (discharge: –10°C to +55°C).
✔ FoxESS Cloud Monitoring
Full real-time monitoring via the FoxESS Cloud platform and app — state of charge, charge/discharge history, and system alerts. Supports tariff-intelligent scheduling to charge at low-rate periods and discharge at peak rates.
✔ 10-Year × 3 Warranty
The EQ4800 carries a 10×3 warranty structure — confirm full warranty terms and registration requirements in the Fox ESS Battery Warranty document. Register via the Fox ESS installer portal at commissioning.
Technical Specifications
| Part Number (Master) |
FE-HV-EQM-4800 / EQM4800 |
| Module Type |
Master (includes BMS — 1 required per stack) |
| Battery Chemistry |
LFP (LiFePO₄) |
| Nominal Energy per Module |
4.66 kWh |
| Usable Capacity (100% DoD) |
4.66 kWh per module |
| 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 |
| Display |
6× LED (Master) |
| Max Modules per Stack |
9 (1× Master + 8× Slave) |
| Max Stack Capacity |
41.93 kWh |
| Operating Temperature — Discharge |
–10°C to +55°C |
| Operating Temperature — Charge |
0°C to +55°C |
| Installation Location |
Indoor or outdoor (stand-mounted) |
| Ingress Protection |
IP65 |
| Max Altitude |
3,000 m |
| Dimensions — L2 stack (W × H × D) |
570 × 386 × 380 mm |
| Certifications |
IEC 62619, EN IEC 61000-6-1/2/3/4, UN38.3 |
| Warranty |
10×3 years (see Fox ESS Battery Warranty Terms) |
Frequently Asked Questions
What is the difference between the EQ4800 and the ECS4300?
The two key differences are capacity and DoD. The EQ4800 offers 4.66 kWh per module at 100% DoD — meaning the full 4.66 kWh is usable. The ECS4300 offers 4.14 kWh at 90% DoD — giving approximately 3.73 kWh usable per module. The EQ4800 also supports up to 9 modules per stack vs 7 for the ECS4300, giving a maximum of 41.93 kWh vs 29.03 kWh. For new installations where maximising storage capacity matters, the EQ4800 is the recommended choice.
Can EQ4800 batteries work with an existing ECM4800 / EC4800 system?
Yes — the EQ4800 is the direct replacement for the ECM4800 and EC4800. The EQ4800 Master (EQM4800) replaces the ECM4800 Master, and EQ4800 Slaves can be mixed with legacy EC4800 Slave modules. When mixing, the stack is limited to a maximum of 7 modules total. The EQ4800 carries updated firmware but is otherwise identical in specification.
Which Fox inverters are compatible?
The EQ4800 battery stack is compatible with Fox ESS H1, KH1, and AIO hybrid inverter ranges. Always consult the Fox ESS Battery Limits Guide for the maximum total battery capacity supported by your specific inverter model and firmware version. Ensure inverter firmware is updated before commissioning.
