Fox ESS · Home battery model
EP5 battery
Fox ESS EP5 is a 5.18 kWh nominal high-voltage LFP battery that can be used alone or in parallel groups of up to four.
Specifications
| Specification | Value |
|---|---|
| Nominal capacity (kWh) | 5.18 |
| Cell chemistry | LFP |
| Round-trip efficiency (%) | ≥95 battery-pack figure |
| Scalable | yes, up to four matching units in parallel |
| Maximum stack capacity (kWh) | 20.8 manufacturer maximum |
| Warranty (years) | 5 from installation, capped at 65 months from manufacture; further 60 months conditional |
| Warranty throughput (MWh) | 16.2 |
| Warranty retained capacity (%) | 70 |
| IP rating | IP65 |
| Operating-temperature range (°C) | charge 0 to 55; discharge -10 to 55 |
| Type | high-voltage battery |
| Depth of discharge | 90% |
| Maximum charge/discharge current (A) | 27 |
| Operating-voltage range (V) | 174 to 219 |
| Dimensions (mm) | 380 × 625 × 147 |
| Weight (kg) | 50.5 with ±5% tolerance |
Fox ESS EP5 is a high-voltage LFP battery. It is a fixed-capacity pack rather than a tower assembled from smaller battery modules. EP5 remains in the current global catalogue, while the main UK residential range now presents EP6 and EP12. It remains compatible with current UK H3 Smart systems, but current UK new-product supply is unconfirmed.
EP5 capacity and parallel groups
Depth of discharge is 90%, which corresponds to about 4.66 kWh before other system limits and operating conditions are considered. Up to four EP5 units can operate in parallel. Multiplying the individual nominal figure gives 20.72 kWh, while the family maximum is rounded to 20.8 kWh.
Voltage and current figures do not prove compatibility with an inverter. The exact Fox ESS inverter and permitted number of parallel packs must support EP5.
The battery-pack efficiency in the table is not whole-system efficiency. Inverter conversion, standby demand, cabling, temperature and control strategy affect the energy returned at the property’s AC connection.
EP5 extension and throughput limits
Under the Fox ESS UK and Ireland battery warranty in force on 23 July 2026, standard cover runs for 60 months from installation but no later than 65 months from manufacture. The extension depends on timely product registration and successful FoxCloud registration using a Fox data logger. Performance cover also ends at the policy’s energy-throughput limit or time limit, whichever comes first.
The throughput value in the specification is a warranty boundary, not a forecast that every battery will fail at that point. The serial number, installation date, registration proof and applicable policy revision should be retained.
Related entries
Manufacturer and reference sources
Brand
Reference type
Home battery model
Last reviewed
31 Jul 2026
Current status
UK new-supply status is unconfirmed.