Shopping listings often arrange portable stations by 500Wh, 1,000Wh or 2,000Wh. It is tempting to call these “small, medium and large refrigerators.” That is a mistake: capacity (Wh) and output power (W) are different constraints.
This comparison owns the capacity-tier choice, not model-specific prices. Use the solar generator buying guide for safety, charging and exact-system evidence, and the battery runtime worksheet for a load calculation.
Compare bands without inventing specifications
| Nominal capacity band | What the number can help with | What the number alone does NOT establish |
|---|---|---|
| About 500Wh | A first-pass estimate for selected small loads and charging | Whether AC inverter output can start a motor or run a heating appliance |
| About 1,000Wh | Longer operation or a wider selected load set | Whether two simultaneous loads exceed continuous or surge output |
| About 2,000Wh | Larger nominal energy reserve or longer use of the same load | Weight, recharge speed, runtime guarantees or building wiring compatibility |
Power-station marketing may also advertise peak output, pass-through operation, solar input and battery chemistry. Every one of these requires exact model evidence rather than inference from the capacity tier.
Worked same-load comparison
For a purely illustrative constant 100W AC load, assume 80% of the advertised Wh is available after the combined reserve and losses. Divide available watt-hours by 100W:
| Station nameplate | Illustrative usable Wh | Simplified 100W load estimate |
|---|---|---|
| 500Wh | 400Wh | 4 hours |
| 1,000Wh | 800Wh | 8 hours |
| 2,000Wh | 1,600Wh | 16 hours |
The 80% fraction is not a measured or standard efficiency. Actual conversion, low-load idle use, temperature, age, reserve and load variability can materially change the result. The DOE energy-data glossary defines kilowatt-hours and related electricity-use units. Those definitions help interpret the illustration; they do not establish an actual station’s output, efficiency or validated runtime.
For a refrigerator, the compressor is intermittent and can draw more power when starting. Do not substitute a daily energy average for its instantaneous starting demand. For a fridge and a separate freezer, use the dual-appliance sizing card.
Three shopping questions matter more than capacity
- Can it run the actual load? Check socket, grounding, continuous AC watts, startup surge and any special waveform or manufacturer limitations.
- Can it be charged and stored safely? Look for exact charger specifications, temperature limits, listed safety/certification evidence, warranty and service support. Do not store a warm or damaged unit in an unsafe enclosure.
- Can someone move and operate it? A large capacity is not useful when the weight, ventilation clearance or noise makes it unsuitable for the household.
Remember that a battery with built-in AC outlets is not a permitted device for backfeeding household wiring. A building-connected system needs professional code-compliant equipment.
Capacity-tier choice card
| Evidence | 500Wh candidate | 1,000Wh candidate | 2,000Wh candidate |
|---|---|---|---|
| Actual loads + Wh/day | |||
| Continuous and surge output | |||
| Usable Wh at chosen load | |||
| Charging sources and time | |||
| Carrying/storing limits | |||
| Verified model and safety records |
Next action: fill the same load and output rows for two exact models before comparing their capacities. Do not rank products by generic capacity alone.