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Power station guides 17 articles
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By use
Buying too small means dead batteries halfway through an outage. Buying too big means paying for capacity you’ll never use and lugging extra pounds around. You can get the size right in three steps with a pen and paper.
Step 1: Find the watts of each device
Look at the label on the device or its power brick. You want the watts (W). If only volts and amps are listed, multiply them: watts = volts × amps (for example, 120V × 1.5A = 180W).
For anything with a motor or compressor (fridge, pump, power tool, AC unit), note that start-up surge can be 3–5 times the running watts.
Step 2: Check the output rating (W)
Add up the watts of everything you’ll run at the same time. Your power station’s continuous output must be higher than that total, and its surge rating must cover the start-up spike of the biggest motor.
Example: fridge (150W running, ~900W start-up) + TV (100W) + router (20W) = 270W running. Any unit rated 1,500W continuous with 2,000W+ surge handles it easily. A 300W unit doesn’t — the fridge’s start-up spike alone exceeds it.
Step 3: Size the capacity (Wh)
For each device, multiply watts by the hours you’ll use it, then add everything up. Divide the total by 0.85 to account for inverter losses:
Capacity needed (Wh) = (watts × hours, summed for all devices) ÷ 0.85
Worked example: an overnight outage
| Device | Watts | Hours | Watt-hours |
|---|---|---|---|
| Refrigerator (averaged) | 60W | 12 | 720Wh |
| Wi-Fi router + modem | 20W | 12 | 240Wh |
| CPAP (no humidifier) | 40W | 8 | 320Wh |
| Two LED lamps | 20W | 4 | 80Wh |
| Phone charging | 15W | 3 | 45Wh |
| Total | 1,405Wh | ||
1,405 ÷ 0.85 ≈ 1,650Wh needed. A 2kWh-class unit such as the Jackery Explorer 2000 v2 (2,042Wh) covers it with margin. A 1kWh unit would get you through if you skip the router overnight and run the fridge in shifts.
Common device wattages
| Device | Typical running watts |
|---|---|
| Phone charging | 10–20W |
| Laptop | 45–100W |
| LED bulb | 8–15W |
| Wi-Fi router + modem | 10–25W |
| Starlink Mini / Standard | 25–40W / 75–100W |
| CPAP (no humidifier / with humidifier) | 30–60W / 70–100W+ |
| TV (LED) | 50–150W |
| Full-size fridge (running / daily average) | 100–250W / 40–80W |
| Chest freezer (daily average) | 30–60W |
| 12V compressor cooler (daily average) | 15–25W |
| Box fan | 50–100W |
| Microwave | 1,000–1,500W |
| Coffee maker / electric kettle | 800–1,500W |
| Space heater | 750–1,500W |
| Window AC unit | 500–1,200W |
Always check your own device’s label; these ranges are typical, not exact.
Quick size guide
| If you need to… | Look for | Example |
|---|---|---|
| Charge phones and laptops, run lights for a weekend | 250–500Wh, 300W+ | EcoFlow RIVER 3, Jackery Explorer 300 Plus |
| Run a CPAP for one or two nights | 300–1,000Wh | Jackery Explorer 300 Plus, Anker SOLIX C1000 Gen 2 |
| Keep a fridge and internet running for a day | 1,000–2,000Wh, 1,500W+ output | Jackery Explorer 1000 v2, Explorer 2000 v2 |
| Cook with a kettle, microwave, or induction plate | 1,800–2,000W+ output | Anker SOLIX C1000 Gen 2, EcoFlow DELTA 3 Plus |
| Back up home circuits or 240V loads for days | 4,000Wh+, 240V | EcoFlow DELTA Pro 3 |
Don’t forget recharging
For multi-day use, capacity matters less than how fast you can refill. Solar input in watts × hours of good sun ≈ energy you get back. A 400W solar input with about 5 hours of strong sun can return roughly 1,500–2,000Wh in ideal conditions; real-world results are usually lower due to clouds, panel angle, and heat.
How long will a power station last? Runtime chart
Find your power station’s capacity in the left column and your total load across the top. Values use runtime ≈ capacity × 0.85 ÷ watts.
| Capacity | 50W load | 100W load | 300W load | 500W load | 1,000W load |
|---|---|---|---|---|---|
| 300Wh | 5.1 h | 2.6 h | 51 min | 31 min | 15 min* |
| 500Wh | 8.5 h | 4.3 h | 1.4 h | 51 min | 26 min |
| 1,000Wh | 17 h | 8.5 h | 2.8 h | 1.7 h | 51 min |
| 2,000Wh | 34 h | 17 h | 5.7 h | 3.4 h | 1.7 h |
| 3,000Wh | 51 h | 25.5 h | 8.5 h | 5.1 h | 2.6 h |
*Only if the unit’s output rating is high enough for the load. Most 300Wh units are limited to about 300W.
Common questions
How long will a 300W power station last?
“300W” in a model name usually describes output; these units typically hold 250–300Wh. That runs a 50W load (a CPAP without humidifier, or a small fan) for about 4–5 hours, or keeps phones and lights going for a weekend.
How long will a 1000W power station last?
A 1kWh-class unit runs a 100W load for about 8.5 hours, a TV for roughly 6–17 hours depending on its size, or an efficient fridge for most of a day. Check the chart above for other loads.
How long will a 2000W power station run a 1500W heater?
About 70 minutes on a 2kWh unit (2,000 × 0.85 ÷ 1,500 ≈ 1.1 hours), assuming its output rating is at least 1,500W. Heaters are the fastest way to drain any battery.
Is it better to buy bigger than I need?
A 20–30% margin is sensible: batteries lose a little capacity over the years, cold weather reduces output, and needs tend to grow. Beyond that, extra capacity is extra cost and weight. Expandable units like the EcoFlow DELTA 3 Plus let you start smaller and add batteries later.
Does the inverter waste power?
Yes — converting battery DC to household AC typically costs 10–15%, which is why we use the 0.85 factor. Use the USB-C and 12V ports for phones, laptops, CPAP DC cords, and 12V coolers to skip the inverter. Also, switch the AC output off when nothing is plugged in; an idle inverter slowly drains the battery.