How many watts do small devices use on backup power?
All six together use about 2,600 watt-hours a day at typical use. A 1 kWh power station covers that about 7.8 hours.
Typical is the middle of our range for each device. Hours count about 85% of the battery as usable. Your own devices may use less or more; the range for each is below.
| Device | While on | Typical energy | On a 1 kWh station |
|---|---|---|---|
| Wi-Fi router and modem | 15–40 W | about 590 Wh a day | about 35 h |
| Phone charging and small USB devices | 10–40 W | about 170 Wh a day | about 123 h |
| A few LED lights | 15–80 W | about 120 Wh per 8 hours of use | about 57 h |
| Laptop and monitor | 45–150 W | about 420 Wh per 8 hours of use | about 16 h |
| Coffee maker | 700–1,500 W | about 980 Wh a day | about 34 minutes of running time |
| Television | 40–250 W | about 330 Wh per 6 hours of use | about 16 h |
Hours for one device on its own, on a full charge. The bigger loads, like a fridge or a furnace blower, have their own pages: refrigerator, furnace blower, CPAP, sump pump.
Wi-Fi router and modem
A Wi-Fi router and modem uses about 590 watt-hours a day (about 24 W on average). A 1 kWh power station runs it about 35 hours of use.
The range: 15 to 40 W while on, 360 to 960 Wh a day. Router and modem draw is steady, so the range reflects hardware differences rather than cycling. A mesh network with several nodes lands at the high end or above it.
Check this yourself: Read the wattage printed on each power adapter. A modem and a router are two separate adapters, and a mesh system is one adapter per node.
Phone charging and small USB devices
Phone and USB charging uses about 170 watt-hours a day (about 7 W on average). A 1 kWh power station runs it about 123 hours of use.
The range: 10 to 40 W while on, 48 to 576 Wh a day. A phone only draws power while it is actually charging, so the duty band is low even when the charger is plugged in all day.
Check this yourself: Check the charger's output rating. Fast chargers draw far more than older 5W bricks.
A few LED lights
A few LED lights uses about 120 watt-hours per 8 hours of use (about 15 W on average). A 1 kWh power station runs it about 57 hours of use.
The range: 15 to 80 W while on, 30 to 480 Wh per 8 hours of use. Depends on how many fixtures you run and for how long. Few households light every room through an outage.
Check this yourself: Count the bulbs and read the wattage on each. Only LED bulbs land in this range; incandescent bulbs are roughly ten times higher.
Laptop and monitor
A laptop and monitor uses about 420 watt-hours per 8 hours of use (about 52 W on average). A 1 kWh power station runs it about 16 hours of use.
The range: 45 to 150 W while on, 144 to 1,200 Wh per 8 hours of use. A laptop draws its full charger rating only while charging a depleted battery. An external monitor adds a steady load on top.
Check this yourself: Read the laptop charger's watt rating and add the monitor separately.
Coffee maker
A coffee maker uses about 980 watt-hours a day while brewing it draws 700–1,500 W, so a 1 kWh power station gives about 34 minutes of running time at the higher figure, and its output must be above that wattage.
The range: 700 to 1,500 W while on, 336 to 2,880 Wh a day. Heating elements draw hard but briefly. The brew cycle matters for output sizing, not for energy.
Check this yourself: Read the nameplate on the base of the machine.
Television
A TV uses about 330 watt-hours per 6 hours of use (about 55 W on average). A 1 kWh power station runs it about 16 hours of use.
The range: 40 to 250 W while on, 72 to 1,500 Wh per 6 hours of use. A modern LED set sits near the low end. Large OLED and older plasma sets sit at or above the high end.
Check this yourself: Read the back-panel label. Screen size and panel technology drive the difference.