Wi-Fi router + modem/ONU: how much battery you need
Wi-Fi router + modem/ONU draws about 12 W (8–20 W range), runs 100% of the time and uses 288 Wh per day. Start-up surge: 12 W.
Tiny load: a 500 Wh station runs a router for ~35 hours. A 12 V mini-UPS is cheaper than a power station for this alone.
Battery needed
| Hours | Wh | Battery (Wh) | Inverter (W) |
|---|---|---|---|
| For 8 hours | 96 | 146 | 14 / 12 |
| For 24 hours | 288 | 437 | 14 / 12 |
| For 72 hours | 864 | 1310 | 14 / 12 |
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Stations that fit (24 h)
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FAQ
How many watts does a Wi-Fi router + modem/ONU use?
Typically 12 W while running, with a range of 8–20 W depending on model and age. Start-up surge can reach 12 W.
How long will a 1000 Wh power station run a Wi-Fi router + modem/ONU?
About 55 hours on the clock, allowing for the 100% duty cycle, inverter losses and a 20% reserve.
What size power station do I need for a Wi-Fi router + modem/ONU overnight (8 h)?
About 146 Wh of battery and an inverter rated at least 14 W continuous with 12 W surge.
Can I run a Wi-Fi router + modem/ONU on solar during an outage?
You need roughly 192 W of panels in winter to replace a day's use (288 Wh), charging through a station with a big enough MPPT input.
Other appliances
1 Approximate values: estimated from motor or heater power and typical figures published online, not from a manufacturer chart. Check your appliance label.
Inverter efficiency 88%, usable depth of discharge 90%, reserve 20%. Full method: How we calculate. source