How we calculate

Simple, published formulas — so you can check every number yourself.

Runtime

Runtime (hours) = capacity (Wh) × 0.85 ÷ device watts. Inverters and conversion lose energy, so not all of a battery's rated capacity reaches your device. We use 0.85, the planning factor Jackery publishes; real results range roughly from 0.8 to 0.9 depending on load and temperature. Cold weather reduces it further.

Cycling appliances

Fridges and freezers don't draw power constantly. Their compressor switches on and off, running about a third of the time according to Virginia Cooperative Extension. We count them at their average draw.

Sizing

• Energy: watts × hours for every device, added up, divided by 0.85.
• Power: the station's continuous AC output must exceed the sum of everything running at once. Motors (fridges, pumps) briefly need more on start-up; a higher surge rating handles that.

Specs

Each model's figures come from the page linked on its spec table, with the date we checked it. We update the list regularly. If a source doesn't state a value, we show "—" rather than guessing.

Independence

WattReckon is not owned by or affiliated with any manufacturer. If we add shop links in the future, they may earn us a commission at no cost to you; that will never change the calculations or the order of results.