If you’re trying to figure out how long a power station will run your devices, this portable power station runtime calculator gives you a fast, realistic estimate.
It’s designed for planning real-world usage—whether you’re running a refrigerator during an outage, powering an RV, or building an off-grid setup. Estimates are based on typical efficiency losses found in inverter-based systems.
Disclosure: This calculator uses generalized efficiency assumptions and does not account for every real-world variable.
Table of Contents
- How to Use the Runtime Calculator
- Runtime Calculator Tool
- What Affects Runtime
- Example Runtime Scenarios
- Why Real Runtime Is Lower Than Advertised
- How to Size the Right Power Station
- FAQs
How to Use the Runtime Calculator
Enter:
- Your battery capacity (Wh)
- Your device wattage (W)
- Adjust efficiency if needed (default is 0.85)
You’ll get an estimate of how many hours your setup can run.
Runtime Calculator Tool
Portable Power Station Runtime Calculator
Estimate how long a battery can run a device using battery capacity, device wattage, and a typical efficiency factor.
What Affects Runtime
1. Inverter Efficiency
Most power stations lose 10–15% of energy converting DC to AC.
2. Device Power Draw
Appliances cycle on and off:
- Refrigerators don’t run 24/7
- Heaters and microwaves spike usage
3. Battery Size
Larger batteries scale runtime directly.
4. Environmental Factors
Cold weather and heavy loads reduce performance.
Example Runtime Scenarios
Refrigerator (150W average)
- 1000Wh → ~5–6 hours
- 2000Wh → ~10–12 hours
- 4000Wh → ~20–24 hours
TV + WiFi (120W)
- 1000Wh → ~7 hours
- 2000Wh → ~14 hours
CPAP Machine (40W)
- 1000Wh → ~20 hours
- 2000Wh → ~40 hours
Why Real Runtime Is Lower Than Advertised
Manufacturers list total battery capacity, but usable energy is lower due to:
- inverter losses
- heat
- system overhead
That’s why this calculator uses an efficiency factor (0.85).
How to Size the Right Power Station
Instead of guessing, use this approach:
- List your essential devices
- Estimate average wattage
- Multiply by hours needed
- Add 20–30% buffer
For details, see my power station sizing guide
FAQs
How accurate is this runtime calculator?
It provides a realistic estimate based on typical efficiency losses. Actual runtime varies based on device behavior and environment.
What is a good efficiency factor?
0.85 is a solid general estimate. High-end systems may perform slightly better.
Can I calculate multiple devices?
Yes—add up total wattage and enter it as one value.
Does this work for solar generators?
Yes. “Solar generator” is just another name for a portable power station.