Backup power planner
What do you need to keep running?
Pick what matters and for how long. We'll tell you if a power bank is enough, or what size of power station you need.
How long?
What to keep running
Where the figures come from. Typical power use, not your exact devices. Check the label or manual if you can. Last checked 28 October 2026.
- Routers: about 6 to 11 W measured on UK broadband routers (ISPreview), 5 to 20 W typical (Zen).
- CPAP: ResMed's own backup battery runs a machine for 10 to 14 hours without the humidifier, but only about 2 to 3 hours with the humidifier and heated tube (ResMed).
- Fridge-freezers: most modern ones use 100 to 300 kWh a year (Household Money Saving). We allow 600 Wh a day, about 220 kWh a year.
- Electric blankets: from about 60 W to 150 W for a double (Ideal Home).
- Power cuts, broadband and the Priority Services Register: GOV.UK Be Ready.