How long does a portable power station last on one charge?
Anywhere from about half an hour to several days, depending on what you plug in. A 1,024 Wh station runs a full-size fridge about 16 hours, a laptop about 17 hours and a 1,500 W space heater about 35 minutes.
The formula is runtime (hours) = battery Wh x efficiency / load W. Big battery and small load: long runtime. Heating loads like heaters and kettles drain any battery fast.
How do I work out how long my power station will last?
Multiply the battery's watt-hours by 0.85, then divide by the watts you are drawing. You need three numbers:
- Battery Wh, from the station's spec sheet. Use the base unit's figure, without add-on batteries.
- Efficiency, the share of battery energy that reaches the outlet. Most makers don't publish it, so we use 0.85.
- Load W, from the appliance's label or a plug-in watt meter. For a fridge or freezer, use its average draw over a day, not its running watts (more on that below).
Worked example: an EcoFlow DELTA 3 Plus holds 1,024 Wh [1]. A laptop is listed at 50 W [12]. 1,024 x 0.85 / 50 = 17.4 hours. Try your own station and load in the runtime calculator.
How long do common appliances last on one charge?
This table runs the formula for four battery sizes at 0.85 efficiency. "Won't run" means the load is over the station's rated AC output, so it shuts off no matter how full the battery is.
| Load | Watts used | 286 Wh (RIVER 3 Plus) | 1,024 Wh (DELTA 3 Plus) | 2,048 Wh (DELTA 3 Max) | 3,840 Wh (SOLIX F3800) |
|---|---|---|---|---|---|
| LED bulb | 8.8 W [14] | 27 h | 98 h | 197 h | 370 h |
| Wi-Fi router | 20 W [10] | 12 h | 43 h | 87 h | 163 h |
| Chest freezer (average) | 25 W [16] | Won't run | 34 h | 69 h | 130 h |
| Laptop | 50 W [12] | 4.8 h | 17 h | 34 h | 65 h |
| Fridge (average) | 52 W [13] | Won't run | 16 h | 33 h | 62 h |
| 42 to 44 inch TV | 63 W [18] | 3.8 h | 13 h | 27 h | 51 h |
| Box fan | 85 W [19] | 2.8 h | 10 h | 20 h | 38 h |
| Microwave | 1,000 W [11] | Won't run | 52 min | 1.7 h | 3.2 h |
| Space heater (high) | 1,500 W [22] | Won't run | 35 min | 1.1 h | 2.1 h |
Battery and output figures: RIVER 3 Plus 286 Wh and 600 W [4], DELTA 3 Plus 1,024 Wh and 1,800 W [1], DELTA 3 Max 2,048 Wh and 2,400 W [5], Anker SOLIX F3800 3,840 Wh and 6,000 W [6]. Times are rounded down, like the calculator.
The RIVER 3 Plus can't run the fridge or freezer because both are listed at 700 running watts [11], over its 600 W rating. A low average doesn't help if the compressor can't start.
Why does a fridge last longer than its watts suggest?
Because a fridge's compressor cycles on and off, so over a day it uses far less than its running watts. Generator charts list a fridge at 700 W while running [10], but the median ENERGY STAR full-size fridge uses 457 kWh a year, which is about 52 W on average [13]. For runtime, the average is what counts: 1,024 x 0.85 / 52 = 16.7 hours on a DELTA 3 Plus.
The running and starting watts still decide whether the station can run the fridge at all. For a station-by-station answer, see the fit pages such as DELTA 3 Plus and a refrigerator, or the 24-hour fridge outage plan.
How long does it last with several things plugged in?
Add up the watts, then use the same formula. Say you run a fridge (52 W average), a Wi-Fi router (20 W), two LED bulbs (8.8 W each) and a laptop (50 W). That is 139.6 W in total. On the DELTA 3 Plus: 1,024 x 0.85 / 139.6 = 6.2 hours.
The calculator does this for you: add each appliance as a row and it sums the running watts, checks the starting surge and gives the runtime.
Why does my power station run out sooner than the math says?
Usually because of losses the spec sheet leaves out. Some energy is lost turning the battery's DC into household AC, and the inverter draws a little power just by being on, even with nothing plugged in. That is why we multiply by 0.85. A few makers publish their own figure: BLUETTI's manual puts the Elite 30 V2 at over 90% [8], and Anker's own runtime formula for the SOLIX S2000 uses 0.9 [9]. Where a maker gives a figure, our station pages use it.
Other things that shorten real runtimes:
- Cold. Batteries hold less in the cold.
- Age. Capacity drops as a battery ages.
- Reserve. Most stations keep a little charge back to protect the battery.
- Your appliance. Real appliances differ from published figures. The label on yours, or a plug-in watt meter, beats any table.
The methods page explains every assumption.
How long will a solar generator run?
On battery alone, exactly as long as a power station of the same size, because a solar generator is a power station sold with solar panels. Solar adds energy only while the sun is up. Each station has a maximum solar input (1,000 W on the DELTA 3 Plus [1], 220 W on the RIVER 3 Plus [4]), and panels rarely deliver their full rating all day. Treat solar as a way to refill the battery between nights, not as a way to run a heavy load through the day.
How can I make one charge last longer?
Draw fewer watts. A few ways that follow from the formula:
- Use USB or 12 V outputs for small devices. They skip the DC to AC conversion that costs part of every watt-hour on the AC outlets.
- Turn the AC output off when you aren't using it, so the inverter isn't drawing power on its own.
- Use low settings on heaters, fans and cookers. A heater on 750 W lasts twice as long as on 1,500 W.
- Cut the extras. Every watt you remove from the total adds runtime.
If the hours still come up short, you need more watt-hours, either a bigger station or an expansion battery. Compare capacities on the stations page and appliance watts on the appliances page.
Related questions
Quick answers
How long does a portable power station last on one charge?
It depends on what you plug in. Runtime = battery Wh x efficiency / load W. A 1,024 Wh station at 0.85 efficiency runs a 50 W laptop about 17 hours, a full-size fridge (about 52 W on average) about 16 hours and a 1,500 W space heater about 35 minutes.
How long will a 1000 Wh power station run a refrigerator?
About 16.7 to 18.8 hours for a typical full-size fridge on a station of 1,024 to 1,152 Wh. The ENERGY STAR median works out to about 52 W on average, so 1,024 Wh x 0.85 / 52 W = 16.7 hours, and the BLUETTI AC180's 1,152 Wh x 0.85 / 52 W = 18.8 hours. Your fridge may use more or less; its yellow EnergyGuide label gives its yearly kWh.
How long will a solar generator run?
A solar generator is a power station sold with solar panels, so on battery alone the math is the same, Wh x efficiency / load W. Solar input adds energy only while the sun is up, and panels rarely deliver their full rating all day.
Why does my power station run out sooner than Wh divided by watts?
Some energy is lost turning the battery's DC into household AC, and the inverter draws a little power just by being on. We assume 0.85 efficiency unless the maker publishes a figure. Cold weather, battery age and a built-in reserve also shorten real runtimes.