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Capacity class

What a 4,000Wh power station actually runs

A capacity figure describes what the battery holds, not what reaches your outlet. Reserve and conversion losses take a share before any appliance sees a watt, and the output rating decides what you can plug in at all.

Research by the Power Station Station Editorial Team

Rated capacity
3,977 Wh
Average across the 3 records in this class.
Usable through AC
3,150 Wh
After 90% usable capacity and 88% conversion efficiency.
Records in class
3
Each one source-checked against the manufacturer’s own published specifications.

Our answer

A 4,000Wh station delivers roughly 3,150Wh through its AC outlets once reserve and conversion losses are taken out, which is what actually drains during an outage.

Current records in this class

Capacity puts these records on the same shelf, not on equal footing. Continuous output, published surge behaviour, solar acceptance, and carrying weight reveal the practical differences.

Source-checked power station records in the 4,000Wh class
RecordCapacityContinuous outputPublished peakWeight
Anker SOLIX F38003,840 Wh6,000 W9,000 W132.3 lb
Goal Zero Yeti PRO 40003,993.6 Wh3,600 W7,200 W115.7 lb
EcoFlow DELTA Pro 34,096 Wh4,000 W8,000 W113.54 lb

A record with no published peak needs model-level verification before a motor start can be relied on.

What this much energy buys you

Each figure is calculated against a station in this class using the same visible planning profile. They are calculations rather than measured results, and a load with a motor still has to clear its startup demand first.

  • Household refrigerator: about 63 hours on the EcoFlow DELTA Pro 3.
  • Chest freezer: about 112 hours on the EcoFlow DELTA Pro 3.
  • Upright freezer: about 68 hours on the Anker SOLIX F3800.
  • Mini fridge: about 140 hours on the Anker SOLIX F3800.
  • 12V portable fridge: about 198 hours on the EcoFlow DELTA Pro 3.
  • Starlink Mini: about 98 hours on the EcoFlow DELTA Pro 3.
  • Wi-Fi router and modem: about 180 hours on the EcoFlow DELTA Pro 3.
  • Laptop computer: about 76 hours on the Anker SOLIX F3800.
  • Television: about 36 hours on the Anker SOLIX F3800.
  • CPAP machine: about 93 hours on the EcoFlow DELTA Pro 3.

When to move up a class, and when not to

Move up when a full day of use exceeds the delivered AC energy above, when a load runs for long unbroken periods, or when you cannot count on recharging between uses.

Do not move up to solve an output problem. If an appliance exceeds the continuous rating, or starts harder than the inverter can supply, a larger battery in the same output class changes nothing. Capacity and output are separate specifications.

Continue through this cluster

Use the next page that answers your unresolved constraint

The 3,000Wh class belowLess weight and lower cost, if the energy still covers the plan.The 5,000Wh class aboveMore delivered energy when a full day of use runs past this class.Every current product recordCompare the full database across capacity classes.Appliance power requirementsStart from the load rather than the hardware.Calculated runtime answersSee every station measured against every load.Outage load plannerSize a whole outage plan rather than one appliance.Portable power guide hubBrowse completed capacity, electrical, appliance, and planning guides.

Evidence used on this page

Important fields are tied to a specific source. Manufacturer claims, government guidance, calculations, and planning assumptions remain separate.

  1. Published specification table plus the comparison chart and FAQ for the banded solar input current.

    official product page

  2. Published specification table covering capacity, chemistry, lifecycles, inverter output, both solar input channels with their voltage and current limits, weight, and warranty.

    official product page

  3. Capacity, output, surge, voltage, chemistry, cycle life, solar inputs, weight, UPS, expansion, and warranty checked.

    official product page