72h Blackout Autonomy

Home Power Cut Backup & Generator Sizer (UK 230V)

Size a home backup battery or generator during UK DNO power cuts for gas combi boilers, broadband ONT routers, fridge-freezers & medical devices.

Select Essential UK Household Loads

Gas Combi Boiler (140W pump/ignition) FTTP ONT + Wi-Fi Router (25W continuous) Fridge-Freezer Avg Load (160W running) Home Medical Concentrator / CPAP (60W) LED Lighting & Phone Charging (50W) Microwave / Travel Kettle (1,200W intermittent)

Target Backup Duration (Hours)

Minimum Continuous Output

375 W

Recommended Battery Capacity (+20% Loss)

5,400 Wh

Carbon Monoxide & BS 7671 UK Generator Safety

Never operate a petrol or diesel generator inside a house, conservatory, porch, shed or garage — fatal carbon monoxide fumes build rapidly. Only install whole-home backup inverters or manual transfer switches via an NICEIC/NAPIT-certified UK electrician in compliance with BS 7671 wiring regulations.