Connectivity backup guide
How long will a battery backup run a Wi-Fi router?
Internet equipment is a relatively small load, but the modem, router, mesh nodes and fiber terminal may all need power for the connection to stay up.
Backup power runtime
Estimate steady-load runtime after inverter losses and a safety reserve.
Runtime = capacity × efficiency × usable battery share ÷ average load. Motor surge, temperature, battery age and device cycling can change real-world runtime.
What changes the answer?
Add every device in the network path
Include the modem or fiber terminal, router and any mesh node that must remain active. Use measured wall power when possible.
Direct DC output can reduce conversion losses
Some backup devices power routers without converting battery DC to household AC first. Only use the correct voltage, polarity and connector specified by the equipment manufacturer.
The provider network also needs power
A working router does not guarantee service if neighborhood cable, fiber or cellular infrastructure is down. Keep a separate communications plan for extended outages.
Use this result as a planning range
Verify that any battery or UPS supports the equipment voltage and does not interrupt power during the transfer to battery.
Review the formulas and public sources in our methodology.
Official references
- Analyzing household electricity loadsU.S. Department of Energy
- Food safety during a power outageFoodSafety.gov
- Generator and carbon-monoxide safetyU.S. Consumer Product Safety Commission