Power Station Runtime Test Log: Record Your Actual Results
A useful runtime record tells you what equipment was used, which loads were connected and what happened under those conditions. It should not start with a result you want to prove. Use this worksheet for your own observations. It contains an illustrative calculation and blank fields for your results.
Record the setup first
- Date, start time and end time.
- Station model and regional version; battery or approved expansion model.
- Firmware, active output settings and charge percentage at the start.
- Appliance models and operating modes.
- Test location and conditions allowed by the equipment manuals.
- Measurement source: station display, compatible plug-in energy meter or a calculation.
Keep these sources separate. A station’s displayed estimate, an appliance label and an energy-meter result are not interchangeable measurements. Do not open an electrical panel or modify wiring to complete a log.
Watts and watt-hours answer different questions
Watts describe power at a moment. Watt-hours describe energy over time. The U.S. Energy Information Administration explains the distinction between power and energy and the relation between watts, kilowatts and kilowatt-hours.
Hypothetical example: a constant 300-watt load running for two hours uses 600 watt-hours at the load. This is arithmetic, not a measured station result. It leaves out conversion losses, idle consumption, varying loads and operating limits. Nominal battery capacity alone does not prove the runtime available at an AC outlet.
Copy this observation table
| Time | Battery % | Connected loads / mode | Input W | Output W | Energy reading / source | Warnings / changes |
|---|---|---|---|---|---|---|
| Start | ||||||
| During test | ||||||
| End |
For an appliance that cycles, record an observation period that captures its actual behavior. If a load changes, note when it changed. Use a measuring device only within its ratings and instructions. If the equipment shows a fault, stop and follow its manual.
Report what happened
- State elapsed time and the reason the observation ended.
- Record whether the station reached an output cutoff, the load was disconnected or the test ended manually.
- List any periods of charging during the test.
- Keep original readings and photos privately if you need them for later comparison.
- Mark missing measurements as missing; do not replace them with advertised figures.
Compare like with like
A second run is useful only when its conditions are recorded. Changes in loads, settings, charging, temperature or battery configuration can explain different outcomes. Label any calculation separately from observed values. A short test does not establish annual reliability, savings or performance in every outage.
For the choice of backup equipment, see gas generators and battery power stations. For fixed circuits, use the installer checklist.
Source
U.S. EIA: measuring electricity, checked 6 October 2026. The worksheet and 300-watt example are illustrative; they are not reported test data.