
Fox ESS Fox CQ7 35 kWh storage bundle ( 1 x CQ7-M and 4 x CQ7-S)
Fox CQ7 35 kWh storage bundle ( 1 x CQ7-M and 4 x CQ7-S) is a Fox ESS battery stack of 5 modules, giving 35 kWh of nominal storage and about 31.5 kWh usable at 90% depth of discharge.
There is no inverter in this package. These are battery modules only. A battery stores energy; it cannot convert it or connect it to the house on its own, so a compatible Fox ESS hybrid inverter is required and is bought separately. The inverter you choose sets the system's AC power output — how many kilowatts it can actually deliver — while this stack sets how long it can deliver them for.
Before you order
- Please note the FE-CQ7-M must be installed with at least two FE-CQ7-S.
| 4 x FE-CQ7-S | Fox ESS CQ7 Slave Promo Stock Only | |
| 1 x FE-CQ7-M | Fox ESS CQ7 Master Promo Stock Only | |
System specification
| Nominal battery capacity | 35 kWh |
| Usable battery capacity at 90% DoD | 31.5 kWh |
| Battery modules | 5 |
| Battery stack nominal voltage | 288 V |
| Battery operating voltage range | 104.4 – 919.8 V |
| Recommended charge / discharge current | 50 A — about 14.4 kW |
| Maximum charge / discharge current | 80 A — about 23.0 kW |
| Peak discharge current | 110 A for 60 s — about 31.7 kW |
| Battery stack height | 885 mm |
| Battery stack width and depth | 660 × 360 mm |
| Battery stack weight | 249.2 kg ±5% |
| Battery chemistry | LFP (LiFePO₄) |
| Module nominal capacity | 7.02 kWh |
| Battery communication | CAN |
| Fire protection function | Yes |
| Depth of discharge | 90% |
| Round-trip efficiency | > 95% |
| Scalability | Up to 14 modules in series |
| Ingress protection | IP65 |
| Installation | Indoor or outdoor, floor standing |
| Operating temperature | Charge 0 to 55 °C, discharge −10 to 55 °C |
| Certification | IEC 62619, IEC 61000-6-1/2/3/4, UN38.3 |
Battery capacity is the manufacturer's nominal figure for this number of modules. Full electrical, mechanical and installation detail for each component is in its own datasheet and installation manual, all of which are in the Documents tab below.
Which inverter does this stack work with?
This is a 5-module stack, and that number is what decides which Fox ESS hybrid inverters will accept it. From Fox's own UK compatibility matrix:
| H1 / AC1 — takes 2 to 7 modules | Yes, e.g. Fox H1 5.0kW Hybrid Inverter with EPS 1PH Gen 2 |
| KH / KA — takes 2 to 7 modules | Yes, e.g. Fox 10kW K Series Single Phase Hybrid Inverter |
| H3 / AC3 — takes 2 to 12 modules | Yes, e.g. FOX ESS H3 8.0KW 3PH Hybrid Inverter with 3PH CT Meter |
| H3 Smart — takes 3 to 12 modules | Yes, e.g. Fox H3 Smart 8.0KW 3ph Hybrid Inverter |
| H3 Pro — takes 4 to 24 modules | Yes, e.g. Fox H3 Pro 20kW 3ph Hybrid Inverter |
| H3 Plus — takes 4 to 42 modules | Yes, e.g. Fox ESS H3 Plus 50kW 3PH Hybrid Inverter |
| PQ1 all-in-one | No — Fox do not list the CQ7 as compatible with PQ1 |
Source: Fox ESS UK product compatibility matrix, 2026 edition, which is in the Documents tab below. Always confirm against the current version before ordering — ask us and we will check it for you.
Whichever you choose, the inverter sets the system's AC output. A 5 kW hybrid on this stack gives a 5 kW system that runs for a long time; a 20 kW hybrid on the same stack gives a 20 kW system that runs for a quarter as long at full output. The battery's own limits are well above either — see the maximum charge and discharge figures in the table above — so in practice the inverter is what you are choosing when you choose the power.
Buying as a package
The components are ordered, delivered and priced as one line, but they are the same products sold individually — each is linked above, with its own specification and documentation. A hybrid inverter and battery installation is notifiable work: it needs a G98 or G99 application to the network operator before commissioning, and MCS certification if it is going on a grant or an export tariff.
Datasheets, installation manuals, warranty documents and declarations of conformity for every component in this package are in the Documents tab below. Contact our sales team at sales@clearraysolar.com for project pricing.
Build your complete solar system
Everything you need in one place.
- Inverters
- Batteries
- Mounting Systems
- Cabling & Accessories
- Protection Devices
Delivery times vary by region:
- UK — 1-2 business days
- Highlands & Islands — 1-2 business days
Returns accepted within 14 days of delivery for unused items in original packaging.


