How long will a power station run a router and modem?
Router and modem backup runtime examples for 15W, 25W and 40W combined loads, including low-load overhead and internet-service limitations.
Measure both power adapters together because network equipment varies widely.
See why this fitsEstimated router-and-modem backup time
usable Wh ÷ average W = hoursUse the row closest to your situation. The explanation below shows what can move the result.
Comparison table
| Battery class | Usable energy | Runtime at 25W | Range at 40–15W |
|---|---|---|---|
| 150Wh | 120Wh | 4.8 hours | 3–8 hours |
| 300Wh | 240Wh | 9.6 hours | 6–16 hours |
| 500Wh | 400Wh | 16 hours | 10–26.7 hours |
| 1,000Wh | 800Wh | 32 hours | 20–53.3 hours |
Planning estimate only. Real runtime varies with temperature, load behavior, battery condition and conversion path.
Use your own watts, hours and reserve.
A realistic input gives you a useful range instead of a false promise.
Open Power Planner →What does this mean
for your choice?
Measure the complete network
A Wi-Fi router may be only one box in the chain. Include the cable modem, fiber ONT, mesh nodes, PoE injector or switch that must remain powered for the connection to work.
Small loads make overhead visible
An AC inverter and the power station's own electronics can consume a meaningful share beside a 15W load. A compatible regulated DC path may improve runtime, but only with the correct voltage, connector and polarity.
Battery power cannot fix the provider
Your equipment can stay on while an upstream cabinet, cable node or provider network is offline. Test the arrangement during a real service interruption and keep a cellular fallback when connectivity is critical.
Check the complete power path.
A large enough battery can still be the wrong setup when its output, cable or regional version does not match.
- Watts for every powered network box
- AC versus compatible regulated DC path
- Low-load auto-shutdown disabled or tested
- Enough runtime plus outage reserve
- Cellular or other fallback for an upstream failure
Practical answers
Can a 300Wh power station run Wi-Fi overnight?
At a 25W combined router-and-modem load, 300Wh provides about 9.6 hours using an 80% usable-energy allowance. Higher overhead or additional network boxes shorten that result.
Why did my station switch off with plenty of charge left?
Some stations use an energy-saving mode that shuts an output off when the load appears too small. Check the low-load or eco setting and test the exact network equipment before an outage.
Will fiber internet work during a blackout?
It depends on the provider's upstream backup as well as your own ONT and router. Keeping local equipment powered does not guarantee that the external network remains available.
Evidence and sources1 official sourceShow sources
Stations worth checking against this calculation
These are relevant specification profiles, not automatic recommendations. Confirm energy, output protocol, cable behavior and the exact regional model before buying.