Why this is the band to buy
Two reasons, and they point the same way.
It covers the load people actually care about. A refrigerator is the appliance that turns an outage from an inconvenience into a loss, and a kilowatt-hour runs one overnight with room for lighting and the network alongside.
Cost per watt-hour bottoms out here. Below about 500Wh the fixed cost of the inverter and electronics is spread over very little capacity. Above about 3,000Wh you start paying for split-phase output and expansion hardware. The middle is where the money goes furthest — the cost page covers that shape.
What a kilowatt-hour runs
| Load | Average draw | Hours from 1,056 Wh |
|---|
| Refrigerator | 150 W cycling average | About 6 hours continuous, far longer in blocks |
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| Router, modem and a laptop | 85 W | About 10.5 hours |
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| Fridge, network and LED lighting | About 250 W | About 3.6 hours continuous |
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| CPAP without humidifier | 30-40 W | About three nights |
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| Furnace blower, cycling | 200-330 W average | 2.7-4.5 hours |
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| Space heater on low | 750 W | About 72 minutes |
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| Window air conditioner | 1,200 W | Under an hour |
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Hours are capacity x 0.85 / draw, using the inverter efficiency figure on the methodology page. Refrigerator draw is the 150W cycling average used throughout this site.
The refrigerator row deserves the caveat. Six hours is the continuous figure; in practice a closed fridge holds temperature for hours between compressor runs, so running it in blocks stretches a kilowatt-hour across a much longer outage — the refrigerator roundup covers that properly.
Three specifications separate units in this band
Capacity is effectively identical across the band — 1,024 to 1,152Wh is noise. What actually differs is these.
1. Recharge speed. Anywhere from under an hour to six hours from a wall outlet. This is the most underrated specification in the category, because outage restoration is usually intermittent before it becomes permanent.
2. Surge rating. Continuous output is 1,800W across most of the band; surge varies from about 2,000W to 2,400W and above. That is what decides whether a refrigerator or a sump pump actually starts — the starting watts page covers why.
3. Weight and expandability. Whether it moves, and whether it grows.
Chemistry is not on the list because everything worth buying in this band is now LiFePO4. If you find one that is not, that is the deciding factor and the answer is no — the chemistry page covers the cycle gap.
Is this the right band for you?
| If your situation is | Band |
|---|
| Devices, lighting and the router only | 500Wh — see that roundup |
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| A refrigerator and the critical list, outages of hours | 1,000Wh — this page |
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| Fridge and freezer through a long outage | 2,000Wh — see that roundup |
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| A full day of critical loads, or a well pump | 3,000Wh — see that roundup |
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| Anything hardwired at 240V | A split-phase unit — see home battery systems |
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Work it from your own load list rather than from the price. The sizing page does that arithmetic, and a meter replaces the guessing entirely.
Making a kilowatt-hour last
- Run the fridge in blocks. Two hours on, four off keeps food safe and roughly triples what the battery covers.
- Unplug standby loads. The microwave clock, the cable box and idle chargers add up to a meaningful share of a kilowatt-hour across a day.
- Use DC where you can. USB output skips the inverter, which saves the 15% conversion loss on everything you charge.
- Recharge in every window. When power returns briefly, plug the battery in first and everything else second.
- Add a panel for anything past a day. The panel arithmetic is less flattering than ratings suggest, but 200W changes the picture.
The short version
- A kilowatt-hour is a refrigerator overnight plus the network and lighting.
- Capacity is identical across the band. Buy on recharge speed and surge.
- LiFePO4 or walk away. Everything worth buying here is.
- Run in blocks. It roughly triples what the battery covers.
