Field notes
W, Wh and mAh: reading specifications with confidence
Two stations can have similar names yet different capabilities. A useful comparison starts with three units often seen side by side: W, Wh and mAh.
Updated:
Fictional household scenario · not a customer account
When this becomes a household question
Imagine a buyer choosing longer backup from the largest watt figure, then comparing it directly with a power bank’s large milliamp-hour number. The problem is not arithmetic: those numbers describe different things.
Watts describe demand now
Watts describe power. Add simultaneous appliance demand and check brief startup requirements separately. Rated and surge figures are not interchangeable. A short advertised peak is not permission to run that load continuously.
Watt-hours describe energy over time
A device actually drawing 100 W for an hour uses about 100 Wh at its input. The battery must also cover losses and station overhead. Its stated watt-hours cannot become exact runtime for any appliance without adjustments. Our calculator lets you change those assumptions.
Milliamp-hours also need a voltage
Milliamp-hours alone do not fairly compare the energy in different batteries. Converting to watt-hours needs the relevant nominal voltage: Wh = mAh × V / 1000. Do not substitute an arbitrary USB output voltage for the battery rating. Without the data, leave the comparison unresolved.
Verification and selection references
Original specification evidence is retained in the editorial research archive. Links below lead to Ukrainian shop pages. Calculations do not guarantee compatibility, runtime or stock.
