Solar, storage & backup · Edinburgh & East Lothian
Fox ESS hybrid inverters, batteries & home backup
Store more of your solar electricity. Choose the right single-phase or three-phase system. Keep essential circuits powered when the grid goes down.
Renew-Able Solutions designs and installs Fox ESS hybrid inverter and battery systems across Edinburgh, East Lothian and wider Central and East Scotland. We can include a partial-house backup design built around the lights, appliances and connections you value most.
Plan my Fox ESS system
What does a Fox ESS hybrid inverter do?
A hybrid inverter brings solar generation and battery storage together. It converts electricity for use in your property and manages energy flowing into and out of a compatible battery. Surplus daytime solar can be stored for the evening; supported charging schedules can also make use of suitable off-peak electricity tariffs.
The inverter rating in kW describes power: how quickly energy can be supplied. The battery capacity in kWh describes stored energy. Both matter when planning an evening’s electricity use or backup during a power cut.
Our guide to hybrid inverters explains the basics. For a complete installation, explore our solar PV and battery storage services.
Single-phase or three-phase: which Fox ESS inverter?
The starting point is your property’s electrical supply, followed by solar-array size, everyday demand and backup priorities. A three-phase inverter requires a suitable three-phase supply; choosing a larger inverter does not upgrade the incoming electricity connection.
SINGLE-PHASE HOMES
H1-G2 and KH series
The H1-G2 range covers 3–6kW, while the KH range covers 7–10.5kW. These provide different levels of power for suitable single-phase properties.
We assess solar input limits, household demand, battery output and the permitted grid connection together. A larger battery does not automatically increase the inverter’s output.
THREE-PHASE PROPERTIES
H3 Smart and H3 Pro
The H3 Smart range covers 5–15kW. The H3 Pro range covers 15–30kW for higher-demand designs, including suitable larger homes and commercial premises.
Backup design must account for loads on each phase, including starting currents. The combined inverter rating is not the power available to one individual circuit.
Ranges shown are manufacturer product families; available UK models and grid approval are checked for each project. Sources: Fox ESS datasheets and H3 Smart specification.
Already have an H1 or H3 system?
Send us the full model numbers and battery details. Original H1 and H3 units have their own compatibility and configuration requirements. Fox also uses AC1, KA and AC3 names for AC-coupled storage variants; they should not be confused with the corresponding solar hybrid models.
Which batteries can Fox ESS hybrid inverters connect to?
Fox ESS offers high-voltage battery options in two useful formats: individual EP battery units and modular EQ stacks. Select the exact inverter and battery combination together, including the required battery management system, module count, cables and firmware.
EP6 and EP12: expandable battery units
The EP6 stores 5.76kWh nominal energy per unit; the EP12 stores 11.52kWh. Both use LFP chemistry and are specified at 90% depth of discharge. As a calculation, that is approximately 5.18kWh and 10.37kWh respectively before allowing for conversion losses and your chosen backup reserve.
| Inverter family | EP6 or EP12 configuration | What to plan |
|---|---|---|
| H1-G2 / KH | 1–4 battery units | Capacity and discharge power for a single-phase home. |
| H3 Smart | 1–4 battery units | Available battery power and demand across the phases. |
| H3 Pro | 1–8 battery units | Approved arrangement across the inverter’s battery inputs. |
Parallel installations require the appropriate junction-box arrangement. These quantities describe approved system configurations, not permission to mix different EP models or generations. See Fox ESS UK’s EP battery guide.
EQ batteries: build a modular stack
EQ stacks combine a master module with matching expansion modules. The current UK range includes EQ2900, EQ4300, EQ4800 and EQ5000. A practical comparison of module counts is below.
| Battery family | H1-G2 / KH | H3 Smart |
|---|---|---|
| EQ2900 | 2–7 modules | 2–7 modules |
| EQ4300 | 2–7 modules | 2–7 modules |
| EQ4800 | 2–9 modules | 3–9 modules |
| EQ5000 | 2–6 modules | 2–6 modules |
Counts include the master module. For example, an H3 Smart EQ4800 stack starts at three modules, with 13.98kWh nominal capacity; an EQ5000 stack starts at two modules, with 9.84kWh. H3 Pro supports two battery inputs, but its exact stack design must be confirmed separately. Read Fox ESS UK’s EQ configuration guide.
We also check the installation location and temperature requirements. Battery heating is model-specific, so an outdoor enclosure rating alone does not establish cold-weather charging performance.
Keep the essentials running
Fox ESS EPS box and partial-house backup
EPS means Emergency Power Supply. A backup installation separates the agreed circuits from the public grid during an outage and supplies them through the inverter’s backup output. Solar panels and a battery alone do not establish this function.
The newer EPS-BOX-SP gateway
Fox ESS UK identifies the EPS-BOX-SP as a single-phase backup gateway compatible with H1-G2 and KH systems, alongside other listed single-phase storage products. It is marketed for whole-home backup, subject to system sizing. Where partial-house backup is the aim, we assess an essential-circuits arrangement and specify the appropriate switching equipment.
The UK guide gives a typical 2–3 second transfer delay. Equipment may restart, so consider a suitable UPS for devices that need uninterrupted power. Its 100A utility rating is a gateway rating, not a promise of 100A battery-backed output. Read the Fox ESS UK gateway specification.
What about three-phase backup?
The EPS-BOX-SP should not be specified as a universal H3 accessory. Fox also documents an EPS Box-TP for three-phase systems. We check the current H3, H3 Smart or H3 Pro requirements and the suitable EPS box or changeover arrangement for the exact model and UK installation.
Which parts of the house could stay on?
Typical priorities include selected LED lighting, a fridge/freezer, the internet router and a small number of sockets. Heating controls and circulation pumps may also be considered after checking their electrical requirements.
Electric showers, EV charging, immersion heaters, cookers and heat pumps can create much larger loads. Their inclusion needs a specific assessment of continuous power, starting demand and simultaneous use. Keeping high-demand circuits outside the backup supply can make the available energy last longer.
For background, read our solar battery storage and EPS guide. Your quotation will identify the circuits actually included in your installation.
How long will a Fox ESS battery provide backup?
Runtime depends on the energy available when the outage begins and the average demand of the backed-up circuits. Battery reserve, temperature, conversion losses and inverter consumption all affect the result.
We agree a reserve setting with you: holding more charge for outages leaves less energy available for daily use. Compatible solar may help sustain the system during an outage, but generation varies and the system must support the required off-grid operating and restart conditions. We check battery-only restart, often called black start, as part of backup design.
If you are also exploring energy stored in your car, our Sigenergy vehicle-to-load and vehicle-to-home guide explains that separate approach.
Designed around your home or business
Our team is based in Tranent and works across Edinburgh, East Lothian and wider Central and East Scotland. We assess your existing electrical installation, solar equipment, energy use and future plans before recommending a Fox ESS system.
Three-phase projects need particular attention to phase loading and available supply capacity. Explore our commercial solar service for larger installations.
What your quotation should cover
- Equipment: exact inverter, battery models, nominal and usable capacity, and any expansion equipment.
- Backup: the agreed circuits, output limits, switching equipment and consumer-unit alterations.
- Installation: location, cable routes, mounting, protection, earthing and commissioning.
- Connection and handover: applicable network application or notification, monitoring setup, charge schedules and backup reserves.
- Costs and cover: installation scope, VAT treatment and the current manufacturer warranty conditions for the supplied equipment.
There is no single installed price that covers every property. A straightforward storage installation differs from a project involving new solar, a larger battery stack or substantial backup-circuit work. Our DNO applications guide explains the connection process. We can also discuss ongoing solar and battery servicing.
Request a Fox ESS installation quoteAlready have Fox ESS?
For setup, settings and video help, open our Fox ESS app guide.
Fox ESS inverter, battery and backup FAQs
Can I add a battery to an existing solar installation?
Often, but the best route depends on the existing inverter, wiring and equipment. We can assess replacing it with a hybrid inverter or using a suitable AC-coupled storage arrangement.
Can I add more batteries later?
Expansion may be possible within the approved configuration. We check module versions, age, state of charge, firmware and manufacturer requirements before recommending an addition. Leaving physical space does not guarantee future compatibility.
Will the EPS box power every appliance?
Only circuits included in the design receive backup. Their combined demand must remain within the inverter, battery and switching equipment limits. A whole-house connection still needs load management where demand can exceed the available power.
Can a single-phase gateway be used with a three-phase hybrid inverter?
The phase arrangement and inverter model must match the manufacturer-approved design. We specify three-phase backup separately and confirm the necessary switching and protection.
Can I charge the battery from the grid?
Suitable systems support scheduled charging. We configure this around your tariff and household use, allowing for losses and the backup reserve. Savings depend on your actual import and export rates and how the system is used.
Can other battery brands connect directly to a Fox ESS hybrid?
Only use an explicitly approved inverter–battery combination. Voltage alone does not establish compatibility: communications, battery management, firmware and manufacturer support also matter.
Let’s plan the right Fox ESS system
Tell us your postcode, any existing solar or battery model numbers, and which circuits you would like to keep running during a power cut. We will help you choose the inverter, battery capacity and backup arrangement for your property.
Talk to our installation team