Battery storage
Fox ESS battery and inverter installerFox ESS.
Fox ESS builds hybrid inverters and the high-voltage EP batteries that sit under them. We fit EP-series batteries with a K-series inverter, which Fox builds to run the panels and the batteries from one unit, whether the array is new or already on the roof. It suits a household that would rather add the storage in steps than size it all at once.
Fox ESS
What it is, and who it suits.
The inverter and the batteries are one system
Fox publishes the K-series as a single-phase hybrid inverter in 7, 8, 9 and 10 kW with three or four MPPTs, running the high-voltage EP batteries on the same unit rather than through a second box.
New array or one already on the roof
Fox lists the K-series as DC-coupled for new installations, AC-coupled for retrofits and battery-ready. That is what lets storage be added to panels that were fitted years earlier, without starting again.
Batteries stack in steps
Up to four EP batteries run in parallel, and Fox requires a junction box when two to four are fitted together. It is the box that takes the battery string into the inverter, and it needs its own space on the wall.
Rated for an outside wall
Fox rates the EP batteries IP65, with natural convection cooling, internal battery warming and built-in fire suppression, floor or wall mounted, indoors or out.
Cold mornings
The published charge window is 0 °C to 55 °C and the discharge window −10 °C to 55 °C, with an optional warm-up function taking the lower limit down to −25 °C.
Monitoring and work modes
Fox monitors through FoxCloud 2.0, in a browser or the app, with a five-second data refresh and work modes including self-use, feed-in priority, back-up, peak shaving and a scheduler. Fox notes some features follow after the initial release.
Published figures
The numbers, and where they come from.
Every line below is the manufacturer's own published figure. The exact model for your house is settled at the survey.
| What | Published figure | Source |
|---|---|---|
| K-series inverter | Single-phase hybrid, published in 7, 8, 9 and 10 kW, with three or four MPPTs | fox-ess.uk |
| System types | DC-coupled for new installations, AC-coupled for retrofits, battery-ready | fox-ess.uk |
| Monitoring | FoxCloud 2.0 in a browser or the app, with a five-second data refresh and work modes including self-use, feed-in priority, back-up and peak shaving | fox-ess.uk |
| Inverter enclosure | IP65, natural cooling, −25 °C to +60 °C with derating from +45 °C | fox-ess.com |
| EP batteries in parallel | Up to four units in parallel; a junction box is required for two to four units | fox-ess.uk |
| EP battery depth of discharge | 90 % | fox-ess.uk |
| EP battery protection | IP65, natural convection cooling, internal battery warming, built-in fire suppression | fox-ess.uk |
| EP battery temperature range | Charge 0 °C to 55 °C, discharge −10 °C to 55 °C; −25 °C with the optional warm-up function | fox-ess.com |
On the day
What fitting a Fox ESS battery involves.
- The inverter and the batteries go on one wall run, with the DC and AC isolators between them and every one labelled.
- Two or more EP batteries in parallel need the Fox junction box, so leave wall space for it beside the string.
- The inverter is IP65 and derates above +45 °C, so a wall that bakes all afternoon is the wrong wall.
- The fixings and what is behind the render are part of the design.
- The work modes are set in the app once it is commissioned, and we set them with you before we leave.
From the Google profile
Homeowners on their storage.
These are reviews of the installation rather than the hardware — most of them name no brand at all.
Where we fit it
Fox ESS installation, region by region.
Each region page lists its towns, its network operators and what its homes are like.
- Fox ESS installer in CheshireCheshire
- Fox ESS installer in Merseyside & WirralMerseyside and the Wirral
- Fox ESS installer in Greater ManchesterGreater Manchester
The long read: Fox ESS batteries, explained.
Where next
The rest of the kit, and the work it goes with.
Other kit we fit
Sources for this page: fox-ess.uk — kh ka series hybrid inverter · fox-ess.uk — foxcloud 2 0 · fox-ess.com — ENKHKADatasheetV2.420260609 · fox-ess.uk — ep battery range · fox-ess.com — ENEP6DatasheetV1.320260526
Start here
Start with a conversation, not a quote.
Tell us the postcode and roughly what you use. We’ll tell you honestly whether the roof is worth doing — and if it isn’t, that’s a perfectly good answer too.
- Takes about a minute
- You get a person, not a brochure
- No obligation, and no visit until you ask for one