Why Your Fridge Runs Longer on a Power Station Than the Math Predicts
A basic runtime calculation assumes an appliance draws its rated watts continuously, but a refrigerator's compressor actually cycles on and off to maintain temperature, typically running only about 30-50% of the time in a well-insulated fridge at normal kitchen temperature — which means the real-world runtime on a power station is often noticeably longer than the simple continuous-draw math suggests, since the battery isn't being drained the whole time.
This duty-cycle behavior is the single biggest reason people are pleasantly surprised by how long their power station actually lasts compared to an online calculator's baseline number.
What a duty cycle actually means
A refrigerator's thermostat only runs the compressor long enough to bring the interior back down to its set temperature, then shuts it off until the temperature drifts back up — over a full day, that adds up to the compressor actively running roughly a third to half of total time, not continuously, even though the fridge appears to be "on" the entire time.
Why the startup surge still matters even with a lower duty cycle
Even though the compressor isn't running constantly, every time it switches back on it still pulls a brief 2-3× surge above its running watts — as covered in the Surge Watts Calculator guide, a power station's surge rating (not just its continuous rating) needs to comfortably cover that repeated restart, which happens dozens of times a day regardless of the lower average duty cycle.