1 kWh: carries the essentials of a 24-hour blackout if you’re disciplined. 2 kWh: the modern sweet spot — fridge + electronics + a microwave or two. 3 kWh: weekend off-grid territory, or a blackout where you don’t have to ration. Runtimes below are calculated, not marketing — with inverter losses and DOE duty-cycle adjustments baked in.
How these tables are calculated
Each runtime in the tables below is computed from three numbers:
- Usable Wh = nominal battery Wh × 0.90 for inverter efficiency. This matches the typical pure-sine inverter loss in modern LFP power stations and is conservative — top units publish 92–94% efficiency under common loads.
- Appliance running watts are taken from the WattBunker wattage chart, which sources from the U.S. Department of Energy’s appliance estimator and the Virginia Tech Cooperative Extension energy publication.
- Duty-cycle adjustment: for compressor-driven loads, the DOE recommends dividing total plugged-in time by three to estimate true compressor runtime. 1 The “Wall-clock hours” column applies that ÷3 factor where it matters.
1,000 Wh tier — runtime by appliance
Representative units: Jackery Explorer 1000 v2 (1,070 Wh, LFP, 4,000 cycles per Jackery’s spec sheet), EcoFlow DELTA 2 (1,024 Wh, LFP), Goal Zero Yeti 1500 (1,505 Wh, the high end of this tier).
Usable AC capacity at 90% inverter efficiency: ~963 Wh (Jackery 1000 v2 reference).
| Appliance | Running W | Active hours | Wall-clock hours |
|---|---|---|---|
| Refrigerator (modern, ~150 W) | 150 | 6.4 | ~19 (× 3 duty) |
| Mini-fridge (80 W) | 80 | 12.0 | ~36 (× 3 duty) |
| CPAP, no humidifier (30 W avg) | 30 | 32 | 32 |
| CPAP w/ humidifier (75 W avg) | 75 | 12.8 | 12.8 |
| 55″ LED TV | 100 | 9.6 | 9.6 |
| Wi-Fi router + cable modem | 15 | 64 | 64 |
| Laptop (45 W) | 45 | 21 | 21 |
| LED ceiling light (15 W) | 15 | 64 | 64 |
| Microwave | 1,000 | ~58 min | ~58 min |
| Window AC, 5,000 BTU | 500 | 1.9 | ~5.7 (× 3 duty) |
Real takeaway for 1 kWh: if you pick one essential — fridge, or CPAP+humidifier, or Wi-Fi+laptop+lights — the 1 kWh tier gets you through the day. Trying to run two or more simultaneously (fridge + microwave + TV at once) and you’ll watch the battery die in half a day.
2,000 Wh tier — runtime by appliance
Representative units: Jackery Explorer 2000 v2 (2,040 Wh), Anker SOLIX C2000 Gen 2 (2,048 Wh), Bluetti AC200L (2,048 Wh), EcoFlow DELTA 2 Max (2,048 Wh). All four are LFP, 3,000–4,000 cycles per their published specs.
Usable AC capacity at 90% inverter efficiency: ~1,840 Wh (using Anker C2000 Gen 2 reference).
| Appliance | Running W | Active hours | Wall-clock hours |
|---|---|---|---|
| Refrigerator (modern, ~150 W) | 150 | 12.3 | ~37 (× 3 duty) |
| Refrigerator (older, 200 W) | 200 | 9.2 | ~28 (× 3 duty) |
| CPAP, no humidifier | 30 | 61 | 61 |
| CPAP w/ humidifier | 75 | 24.5 | 24.5 |
| Window AC, 5,000 BTU | 500 | 3.7 | ~11 (× 3 duty) |
| Window AC, 8,000 BTU | 800 | 2.3 | ~7 (× 3 duty) |
| Sump pump (½ HP, 900 W) | 900 | 2.0 (active) | depends on inflow |
| 55″ LED TV | 100 | 18 | 18 |
| Microwave (cumulative) | 1,000 | ~110 min | 110 min |
| Coffee maker (drip) | 1,000 | ~110 min | 110 min |
Real takeaway for 2 kWh: this is the tier where you stop having to choose. Fridge for a full 24 hours + Wi-Fi + a few microwave heatups + phone charging fits comfortably with margin. The reason this class exists.
3,000 Wh tier — runtime by appliance
Representative unit: Bluetti Elite 300 (3,014 Wh, LFP, 6,000 cycles per Bluetti’s spec sheet — the highest cycle count in this tier). Other units in or near this tier: Anker SOLIX F3800 (3,840 Wh, technically a step above).
Usable AC capacity at 90% inverter efficiency: ~2,713 Wh (Bluetti Elite 300 reference).
| Appliance | Running W | Active hours | Wall-clock hours |
|---|---|---|---|
| Refrigerator (modern) | 150 | 18.1 | ~54 (× 3 duty) |
| Window AC, 8,000 BTU | 800 | 3.4 | ~10 (× 3 duty) |
| Window AC, 10,000 BTU | 1,100 | 2.5 | ~7.4 (× 3 duty) |
| Mini-split, 12,000 BTU (efficient) | 900 | 3.0 | ~6 (with inverter modulation) |
| Space heater (1500 W max) | 1,500 | 1.8 | 1.8 |
| Induction cooktop, single burner | 1,800 | 1.5 | 1.5 |
| CPAP w/ humidifier | 75 | 36 | 36 |
| 12 V cooler (compressor avg) | 40 | 68 | ~140 (50% duty) |
| EV charger Level 1 (1,440 W) | 1,440 | 1.9 | ~6 EV miles |
Real takeaway for 3 kWh: this is where you can run a window AC for a meaningful chunk of an afternoon — about 7 hours of wall-clock time on a 10,000 BTU unit factoring its compressor cycling. Or 36 hours of CPAP. Or two days of fridge plus all the small loads of a normal household.
Mixed loads: what happens when you stack
The tables above are single-load runtimes. Real life is mixed. Two simple rules:
Energy adds. Fridge (1,500 Wh/day adjusted) + router (250 Wh) + laptop charging (200 Wh) + lights (100 Wh) + 4 phone charges (60 Wh) + a 30-minute microwave session (500 Wh) = ~2,610 Wh. That’s a 2 kWh battery being insufficient and a 3 kWh battery covering 24 hours with margin.
Surge multiplies. Two compressor-driven loads can spike simultaneously. A 1,500 W microwave already at full draw plus a fridge compressor restart adding another 600 W of surge can briefly demand 4,500 W. Most 2 kWh power stations cap at 4,000 W peak. A 3 kWh class unit (with 4,800–6,000 W peak) handles this without sweating.
“(Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption.”
The picks by tier
1 kWh: Jackery Explorer 1000 v2
Smallest viable unit for “fridge through the night.” 1,070 Wh, 23.8 lb, 4,000-cycle LFP per Jackery’s product page. The travel-friendly choice when weight matters more than headroom. Full review →
2 kWh: the all-rounder slot
Jackery Explorer 2000 v2
The 2 kWh class is where 90% of buyers should land. Jackery 2000 v2, Anker SOLIX C2000 Gen 2, and Bluetti AC200L are the three top contenders. The Jackery wins on Amazon ratings and recharge speed; Anker on weight and idle draw; Bluetti on a slightly larger inverter peak. Compare them →.
3 kWh: Bluetti Elite 300
3,014 Wh nominal, 6,000-cycle LFP — the highest cycle rating in the catalog as of April 2026 — and a 2,400 W inverter. The “I want one battery that runs an AC and the fridge for an afternoon” answer. Full review →
Use the calculator
Pick the appliances you actually want to run, set the runtime, and let the calculator return the closest-fit power station with the math already done:
Sources
Battery capacities, chemistry, cycle ratings, and AC inverter peak figures cited above come from each manufacturer’s published spec sheet (Jackery, Anker, Bluetti, EcoFlow). Refresh against the live Amazon US listing before any consequential purchase. Inverter efficiency at 90% is a working assumption that matches typical pure-sine performance under steady load; actual values can be a few points higher or lower depending on the load level. The Virginia Tech Cooperative Extension publication 2901-9014 underpins the appliance running-watt figures used throughout the runtime tables.
Footnotes
-
U.S. Department of Energy — Office of Energy Efficiency & Renewable Energy. Estimating Appliance and Home Electronic Energy Use. Formula and refrigerator duty-cycle rule. energy.gov/energysaver/estimating-appliance-and-home-electronic-energy-use ↩
FAQ
Does a 1,000 Wh power station really run a fridge for 24 hours? +
How is the runtime calculated? +
What if I run multiple appliances at once? +
Which 2 kWh power station has the highest real-world runtime? +
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