
Fox ESS EQ3300-H 12.8kWh 256V High Voltage Heated Battery Stack, Master and Slave
The Fox ESS EQ3300-H 12.8kWh stack is a high voltage storage block supplied already made up: four LiFePO4 modules of 3.2kWh each, one master and three slave modules. It banks the energy the solar array produces during the day and releases it in the evening, or when the grid is down, without having to pick the individual modules one by one.
The master module carries the management system that watches every cell and talks to the hybrid inverter over CAN: it is the part that holds the stack together, while the slaves only add capacity. The stack does not stop here either, since it takes up to six modules in total, that is 19.2kWh: it starts at 12.8kWh and grows when consumption or array size changes.
Every module in this block has built-in heating, which widens the usable temperature range and makes it the right choice for garages, cellars and unheated plant rooms. Heated and non-heated modules can share the same system, but if a single battery in the stack does not support heating the function is disabled system-wide. The cells are lithium iron phosphate with a declared depth of discharge of 90%, and mounting is plug-in. Check the inverter model against the official Fox ESS compatibility list; installation and commissioning must be carried out by qualified personnel.
Key strengths
Technical specifications
| Feature | Value |
|---|---|
| Product code | FE-HV-EQ-A-4-3.3-12.8 |
| Manufacturer | Fox ESS |
| Series | EQ3300-H |
| Type | High voltage storage stack |
| Contents | 1 master module + three slave modules EQ3300-H, all heated |
| Chemistry | LiFePO4 (lithium iron phosphate) |
| Nominal energy | 12.8kWh (4 x 3.2kWh) |
| Usable energy | 11.52kWh (12.8kWh at 90% DoD) |
| Nominal system voltage | 256V (4 modules of 64V in series) |
| Operating voltage range | 232-292V |
| Nominal capacity | 50Ah |
| Depth of discharge (DoD) | 90% |
| Maximum charge and discharge current | 50A (about 12800W at 256V) |
| Recommended discharge current | 25A (about 6400W at 256V) |
| Peak discharge current | 65A for 60s (about 16640W at 256V) |
| Modules per stack | 2 to 6 (1 master and up to 5 slaves) |
| Maximum system capacity | 19.2kWh |
| Heating | Built into every module |
| Communication | CAN, from the master module to the inverter |
| Ingress protection | IP65 |
| Weight | 142.8kg |
| Source of the technical data | Figures declared by Fox ESS, EQ3300 datasheet (EQ3300-L4 configuration); power values are derived from the declared currents at nominal voltage |