Portable Power Station Runtime Calculator | How Long It Runs Your Appliances, Required Capacity (Wh) and Rated Output, Solar Panel, Car and AC Charging Time, mAh to Wh and Flying with Batteries
The Portable Power Station Runtime Calculator answers questions such as “how long will a 1000Wh power station run a fridge?”, “how many Wh do I need for an electric blanket overnight while car camping in winter?” and “how many days does a 200W solar panel take to fill it up?”. Set the capacity (Wh) and conversion efficiency, then list your appliances from 17 presets (fridge, electric blanket, fan, CPAP, kettle, microwave, rice cooker and more, with editable wattage) along with how many and how many hours a day you use them. It shows how long everything lasts if run together, how many days your daily use lasts, whether the total load fits within the rated output, and whether motor appliances’ start-up power fits within the surge output, then suggests the minimum capacity and rated output for the number of days you need. Power cut, winter car camping, summer camping and two nights of CPAP are one tap away. For charging, it works out the time from a wall outlet (AC input), a car socket (12V or 24V) or a solar panel (with system efficiency and seasonal peak sun hours), plus the electricity cost of a full charge. It also converts a power bank’s mAh to Wh, estimates how many times it charges a phone and checks whether it can go on a plane (the 100Wh and 160Wh limits). A runtime table by capacity, LiFePO4 versus NCM battery life and a glossary (rated output, pure sine wave, pass-through, UPS and more) are included.
How long a portable power station runs your appliances
Enter the capacity (Wh) and the appliances you will use to see how many hours or days it lasts, whether they can run together (rated output) and what capacity you need. Runtime = capacity × conversion efficiency ÷ power draw.
Conversion efficiency (AC output loss)
Start from a common scenario
| Appliance | Power | Qty | Hours a day | Energy a day | |
|---|---|---|---|---|---|
| Fridge (about 400 L) Calculated at an average of 35 W (it cycles on and off) Needs a lot of power to start | 840 Wh | ||||
| LED bulb (60 W equivalent) | 96 Wh | ||||
| Phone charging | 60 Wh | ||||
| Wi-Fi router | 240 Wh | ||||
| LCD TV (32 inch) | 150 Wh |
Wattages are typical values. Enter the power consumption (W) from the appliance’s label or manual for a more accurate result.
Running everything together
6 h 2 min
Average 141 W, usable energy 850 Wh
Days at your daily use
0.6 days
Uses 1,386 Wh a day
Total power used at once
256 W
Within the 1,500 W rated output, so they can run together
Start-up power (estimate)
556 W
Within the 3,000 W surge output
What capacity do you need?
The capacity needed to use the appliances above for their daily hours. You can add a reserve so the battery isn’t fully drained.
Capacity needed
1,812 Wh
1,386 Wh × 1 days ÷ 85% efficiency
Suggested capacity
2,000 Wh or more
Your 1,000 Wh is not enough
Suggested rated output
300 W or more
256 W used at once
How long one appliance runs on its own
Runtime with 1,000 Wh and 85% efficiency when only that appliance is running.
| Appliance | Power | Runtime | Rated output |
|---|---|---|---|
| Phone charging | 15 W | 2.4 days (57 h) | Yes |
| Laptop | 50 W | 17 h | Yes |
| LED bulb (60 W equivalent) | 8 W | 4.4 days (106 h) | Yes |
| LED lantern | 5 W | 7.1 days (170 h) | Yes |
| Wi-Fi router | 10 W | 3.5 days (85 h) | Yes |
| LCD TV (32 inch) | 50 W | 17 h | Yes |
| Fan (DC motor) | 15 W | 2.4 days (57 h) | Yes |
| Fan (AC motor) | 35 W | 24 h 17 min | Yes |
| Electric blanket | 55 W (average 25 W) | 34 h | Yes |
| Fridge (about 400 L) | 150 W (average 35 W) | 24 h 17 min | Yes |
| Car fridge (portable fridge) | 45 W (average 20 W) | 42 h 30 min | Yes |
| CPAP (without humidifier) | 40 W | 21 h 15 min | Yes |
| Rice cooker (small, 3 cups) | 350 W | 2 h 26 min | Yes |
| Electric kettle | 1200 W | 43 min | Yes |
| Microwave (heating at 500 W) | 1000 W | 51 min | Yes |
| Hair dryer | 1200 W | 43 min | Yes |
| Electric griddle | 1300 W | 39 min | Yes |
Results are estimates. Appliances’ power use changes with how you use them, their settings and the temperature, and batteries deliver less in the cold (near 0°C) and as they age. For life-critical equipment such as CPAP or home oxygen, check with the equipment maker too and choose a capacity with plenty of margin.
ABOUT
About Portable Power Station Runtime Calculator | How Long It Runs Your Appliances, Required Capacity (Wh) and Rated Output, Solar Panel, Car and AC Charging Time, mAh to Wh and Flying with Batteries
The Portable Power Station Runtime Calculator is a free tool that works out, from the capacity (Wh) and the appliances you plan to use, how many hours or days a power station lasts, whether the appliances can run at the same time (rated and surge output) and what capacity you need. It also gives solar panel, car and wall outlet charging time and cost, converts mAh to Wh and checks whether a battery can go on a plane.
How to use Portable Power Station Runtime Calculator | How Long It Runs Your Appliances, Required Capacity (Wh) and Rated Output, Solar Panel, Car and AC Charging Time, mAh to Wh and Flying with Batteries
- 1Enter the power station’s capacity (Wh), the conversion efficiency (about 85% for AC output) and your model’s rated output and surge output
- 2Pick a scenario such as “Power cut” or “Winter car camping”, or add appliances and enter how many, hours a day and wattage (W)
- 3Check how long everything lasts if run together, how many days your daily use lasts and whether it all fits within the output
- 4In “What capacity do you need?”, enter the number of days and how much charge to keep in reserve to see the capacity and rated output you need
- 5Use the “Charging time” tab for wall outlet, car and solar charging, and the “mAh to Wh and flying” tab for power bank Wh and airline rules
Great for
- Working out what size power station you need for a fridge and phone charging during a power cut or while sheltering at home
- Checking whether an electric blanket lasts the night when car camping in winter, or how long a fan or car fridge runs while camping in summer
- Finding out how many nights a CPAP can run when travelling or during an outage
- Comparing models to see whether a kettle, microwave or hair dryer fits within the rated output
- Estimating how many days a solar panel of a given wattage takes to fully charge the battery in each season
- Converting a power bank’s mAh to Wh to see whether you can take it on a plane
Good to know
- Runtime is capacity (Wh) × conversion efficiency ÷ power draw (W). The battery stores direct current, so running appliances from the AC outlet loses about 15-20% in the inverter. With 1,000 Wh and 85% efficiency, for example, a fridge averaging 35 W runs for about 24 hours and an electric blanket averaging 25 W for about 34 hours.
- Fridges, electric blankets and car fridges switch on and off to hold their temperature, so their energy use is calculated from their average power rather than the power while running (a fridge using about 300 kWh a year ÷ 8,760 hours ≈ 35 W). Opening the door often or hot weather raises the average.
- If the total power of appliances used at the same time exceeds the rated output, the power station shuts off. Fridges and AC-motor fans need several times their power to start, so the tool estimates start-up power at 3 times the running power and compares it with the surge output.
- Required capacity is daily energy × days ÷ conversion efficiency ÷ (1 − reserve). Batteries deliver less in the cold (near 0°C) and lose capacity over the years, so choosing a model 20-30% larger than the result is safer.
- Daily solar input is estimated as panel watts × system efficiency × peak sun hours. A panel’s rating is measured under ideal conditions, and heat, angle, shade and conversion losses bring the real output to about 60-80%. The cost of a full charge uses Japan’s standard guide price of 31 yen per kWh, which you can change.
- On planes, power banks of 100 Wh or less can be carried in the cabin, those over 100 Wh up to 160 Wh need airline approval and are limited to two, and anything over 160 Wh is not allowed. None of them can go in checked baggage. Airlines may have their own extra rules, so check before you fly.
Questions this tool answers
Use Portable Power Station Runtime Calculator | How Long It Runs Your Appliances, Required Capacity (Wh) and Rated Output, Solar Panel, Car and AC Charging Time, mAh to Wh and Flying with Batteries for searches like these:
- Calculate how many hours a portable power station runs my appliances
- Find the power station capacity I need for a power cut, car camping or camping
- Check whether a power station can run a fridge, electric blanket or CPAP
- Work out the charging time with a solar panel or car
- Convert mAh to Wh
- Check whether a power bank or power station can go on a plane
FAQ
- How do I calculate how long a portable power station will last?
- Capacity (Wh) × 0.85 ÷ the appliance’s power (W). The 0.85 is a typical AC conversion efficiency. A 500 Wh power station running a 50 W laptop gives 500 × 0.85 ÷ 50 = about 8.5 hours.
- How long will a 1000Wh power station run a fridge?
- About 24 hours for a typical household fridge of around 400 L averaging 35 W. It needs several hundred watts to start, so choose a model with at least 500 W rated output and plenty of surge output. Hot weather and frequent door opening shorten the time.
- How many Wh do I need to run an electric blanket overnight in the car?
- An electric blanket averaging 25 W for 8 hours uses 200 Wh. Adding phone charging and a lantern, and allowing for efficiency and a reserve, about 400 Wh is a good target, so a 300-500 Wh model lasts the night. The cold reduces usable capacity, so leave some margin.
- How many days does a solar panel take to fully charge a power station?
- Daily input is roughly panel watts × 0.7 × peak sun hours. A 200 W panel on a sunny spring or autumn day (4 hours) gives about 560 Wh a day, so a 1,000 Wh power station takes about 1.8 days to fill.
- What is the difference between rated output and surge output?
- Rated output is the most power the station can supply continuously, and surge output is the most it can supply for a moment at start-up. A kettle or hair dryer (around 1,200 W) needs at least 1,200 W rated output, and appliances that draw a lot when starting, such as fridges, need headroom in surge output.
- How many Wh is 10000mAh, and can I take it on a plane?
- At a cell voltage of 3.7 V it is 10,000 × 3.7 ÷ 1,000 = 37 Wh. That is 100 Wh or less, so it can go in the cabin but not in checked baggage. At 3.7 V, 100 Wh is about 27,000 mAh and 160 Wh about 43,200 mAh.
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