How to Power a CPAP Machine During a Power Outage
A portable power station or a dedicated CPAP battery is the most practical way to keep a CPAP running through a power outage — sizing depends on the machine's wattage (roughly 7-75W depending on model and humidifier setting) and how many nights of backup you want, which the CPAP Runtime Calculator estimates directly from your battery's capacity and your machine's typical draw.
For anyone who depends on CPAP therapy nightly, this is a genuinely important, high-stakes planning question worth working through before an outage happens, not during one.
The two main backup options
A general-purpose portable power station covers a CPAP alongside other needs (phone charging, lights, a small fridge), while a CPAP-specific battery is purpose-built and often more compact, though typically with less capacity and no ability to power anything else — the right choice depends on whether you want single-purpose reliability or multi-use flexibility.
Testing before you actually need it
As covered in the medical disclaimer on the calculator itself, the single most valuable thing anyone dependent on CPAP therapy can do is test their exact machine and battery combination in advance — actual wattage varies enough by model, pressure setting, and mask type that a real test removes the uncertainty a calculator alone can't fully resolve.