Fox ESS batteries
The sensible way into solar and storage at the same time, without paying for a badge you did not need.
4.7 on Trustpilot
No obligation
Why people ask for Fox ESS by name
Fox ESS is one of the most-fitted inverter and battery brands in the country, and that is the useful fact about it. A lot of installed units means a lot of engineers who know them, parts that are actually in the country, and failure modes that are understood rather than theoretical.
What it does well is the combined job. A Fox hybrid inverter with a stack of Fox modules alongside it handles the panels and the storage in one go, on one warranty, for noticeably less than assembling the same capability from a premium battery and a separate inverter. On a new install where the budget has to stretch to scaffold and panels as well, that difference often buys two more panels.
It is the value option in our range and we say so plainly. Value does not mean cheap: it means the money goes into capability rather than into a name.
- Stackable, so the capacity matches the house rather than a fixed figure
- Hybrid inverter and battery from one manufacturer, on one warranty
- One of the most widely fitted brands in the UK, so support is real
- Zero-rated for VAT until 31 March 2027
We are a Fox ESS installer
The full Fox ESS range
We fit the whole Fox ESS range, every inverter size and every battery module they make. The three below are how the range maps onto real houses; yours is sized from your usage.
Roughly how the range maps onto real houses:
New solar and storage
Panels and battery going in together, which is how most people buy it.
- Arrangement
- Hybrid inverter plus a stack of modules
- Why it is good value
- One box does the inverting and the storage
- Expandable
- Add modules to the stack later
- Grid
- G98 or G99 handled for you
A bigger house
Higher demand, an EV on the drive, or a heat pump coming.
- Approach
- A taller stack, specified from your usage
- Sizing input
- Half-hourly data where you have it
- Future proofing
- We leave space and cabling for another module
- Note
- Size to the usage, not to the roof
Adding to an existing array
Panels already on the roof.
- Arrangement
- AC coupled alongside your current inverter
- Works with
- Any inverter brand
- Tariff
- Charge and discharge windows set at handover
- App
- FoxCloud, set up with you before we leave
How Fox ESS compares
| Fox ESS | Tesla Powerwall | Hanchu ESS | |
|---|---|---|---|
| Capacity | Stackable, sized to the house | 13.5 kWh, stack more | Modular, add later |
| Inverter | Fox hybrid, same manufacturer | Built into the unit | Hanchu hybrid, same manufacturer |
| Cost per usable kWh | The lowest in our range | Higher | Low |
| Whole-home backup | Essential circuits | Yes, with a gateway | Available |
| How widely fitted | Very, so support is everywhere | Very | Growing |
| Best for | Stretching a budget across panels and storage | Backup and a new install | One ecosystem including the charger |
The honest verdict
Why we fit a lot of them
- The most usable kWh per pound in the range, which frees budget for more panels
- Widely enough fitted that any competent engineer has seen one
- Stackable, so nobody pays for capacity the house will never cycle
- One manufacturer across the inverter and the battery, so the warranty is one conversation
What to weigh up
- Backup covers essential circuits rather than the whole house, so if you want everything staying on in a cut, say so at the design stage
- It is a value proposition, and somebody who wants the most recognisable badge on the garage wall will not be satisfied by that argument
- A battery makes no electricity; without a cheap tariff window to fill it from, the payback is much longer than people expect
- Stacking later is easy only if the space and cable route were left for it, which is a design decision on day one
Questions we get asked about Fox ESS
Is Fox ESS a good brand?
It is one of the most widely fitted inverter and battery brands in the UK, which means engineers know them and parts exist. We fit a lot and it is the value option in our range.
How big a battery do I need?
It comes from what you use and when, not from the size of your roof. Somebody out all day with an EV wants a different system from a retired couple at home using power as they make it. We size it from your usage.
Can I add more later?
Yes, and it is one of the reasons we like it. Tell us you might and we will leave the space and the cabling, which is what makes adding a module a short job rather than a rebuild.
Does it do backup?
It will run essential circuits through a power cut. If you want the whole house to stay on, that is a different specification and we need to know before the design, not after.
What is the warranty?
Fox warrant the battery and the inverter separately, both with a guaranteed minimum capacity at the end of the term for the battery. We register both for you, and our workmanship warranty sits on top.
Get a price for a Fox ESS system.
We come and look at the house, tell you whether this is the right unit for it, and put the price in writing.