What size power station do you need to keep Wi-Fi up for 12 hours?
Short answer: 203 Wh of rated capacity — that's the ~300 Wh — compact class. Overnight internet for smart-home gear, cameras, and working late.
The math, appliance by appliance
Appliance
Avg draw
Hours used
Energy
Wi-Fi router + modem
12 W
12 h
144 Wh
Energy needed over 12 hours
144 Wh
÷ 0.85 inverter efficiency
169 Wh
× 1.2 headroom (ageing, cold, overrun)
203 Wh
Recommended: ~300 Wh — compact class. Output check: 12 W continuous, 12 W surge.
Fridges and freezers use their average cycling draw for energy and full compressor draw for the output check — that's why the numbers differ from the label.
The bare energy need is 169 Wh after inverter losses; the extra 20% covers battery ageing, cold weather, and outages running long. A smaller unit works on a good day — this size works on a bad one.
What about output watts, not just capacity?
These loads draw 12 W continuously with no motor surges — any unit big enough on capacity is big enough on output.
Could solar keep this running indefinitely?
Roughly 96 W of panels replaces a day's usage with ~4 hours of decent sun at real-world (75%) efficiency. Half that solar doubles your runtime instead of sustaining it.