How long will a power station run a CPAP?

A CPAP is the purchase that tolerates the least hand-waving: if the battery dies at 3am, the machine stops. The good news is that the machine itself is a light load — most draw 30–60W with the humidifier off. The heated humidifier and heated hose are what drain batteries: they can more than double the draw, which is why the table below shows both columns.

Two practical notes before the numbers. First, runtimes here use a 40W / 90W average draw at 85% usable capacity — if you know your machine's actual wattage (it's on the power brick), scale accordingly. Second, most CPAPs run on 24V DC internally; a brand DC adapter cable skips the inverter and typically stretches runtime 20–40% beyond the AC numbers below. The table is the plug-into-the-AC-outlet case — conservative relative to a DC adapter, but not relative to a higher-wattage machine, so still scale by the number on your own power brick.

How the table is computed: runtime = rated capacity × 85% usable ÷ average draw. Prices are today's price at each brand's official store (including on-page promo prices where we can verify them); the table re-ranks every night. Omitted: out-of-stock models, models without a current battery-only price, models whose runtime rounds below half a night, and stations below 150W continuous output (or without a published rating) — they can't run this load regardless of capacity. Methodology.