ECS 10.4 (10.4 kWh)
Fox ESS's stackable ECS range is the credible value-tier home battery in 2026. Honest pricing per usable kWh, a modular form factor that fits real UK garages, and a UK distributor network that is now competitive on response times.
- Round-trip efficiency
- Above 87%
- Running cost
- £-590/yr
- Installed
- £5,200 to £7,400 installed
Editorial render. Not a manufacturer photograph; we do not redistribute press imagery without a licence.
Primary question · Is the Fox ESS ECS the honest value pick on a budget battery install?
Budget-led installs where the householder wants real storage on a time-of-use tariff without paying the premium-brand badge.
£5,200 to £7,400 installed
- Honest pricing per usable kWh
- Modular stackable form factor
- Decent app for the tier
- Less long-term UK field data than Tesla or GivEnergy
- Installer quality varies sharply by region
Open the cost planner to estimate your installed price.
Key specifications
- Usable capacity
- 10.4 kWh
- Continuous power
- 5 kW
- Round-trip efficiency
- Above 87%
- Warranty
- 10 years, 80% capacity retention
- , Honest pricing per usable kWh
- , Modular stackable form factor
- , Decent app for the tier
- , Less long-term UK field data than Tesla or GivEnergy
- , Installer quality varies sharply by region
GivEnergy★★★★★All-In-One 13.5 kWh- Round-trip efficiency
- Above 88%
- Running cost
- £-760/yr
Single-cabinet plant roomsBritish installer supportTariff-led householdsReadHouse Verdict9.0/10
Tesla★★★★★Powerwall 3 (13.5 kWh)- Round-trip efficiency
- Above 90%
- Running cost
- £-780/yr
Solar + battery togetherTime-of-use tariffsApp-first householdsReadHouse Verdict9.4/10
If your brief matches "budget-led installs where the householder wants real storage on a time-of-use tariff without paying the premium-brand badge.", the ECS 10.4 (10.4 kWh) is a confident pick. If it doesn't, the alternatives above are more honest answers.
Estimate your installed cost
The planner uses your specific home; not a brochure number.