The power brick on your CPAP says 90W. The battery you're looking at says 500Wh. Dividing one by the other suggests 5.5 hours before losses. But the adapter's output rating is not your machine's overnight energy use. Choosing a backup starts with knowing which number you are reading.
The short answer: CPAP machine wattage depends on the model, settings, and power path. ResMed lists typical system consumption of 53W for AirSense 10, 56.1W for AirSense 11, and 6.3W for AirMini in the manuals linked below. These are published specifications, not our overnight measurements. For battery sizing, multiply your average watts by hours of use, then account for the backup's conversion losses.
Jump to: manufacturer wattage table, battery sizing for one or two nights, or the CPAP runtime calculator.
Updated October 15, 2026: added direct manufacturer citations and battery-sizing tables. Corrected earlier advice that treated adapter output and system consumption as interchangeable, assumed a particular humidifier setting for the typical figures, and promised runtime from specification-only calculations. We have not tested these machines or power stations.
CPAP Wattage by Model: The Manufacturer Figures
These are different kinds of specifications. An adapter's DC output rating is not the same measurement as a system's input consumption. The Philips and Luna manuals below list AC input limits but do not give a comparable typical wattage in their cited electrical sections. We do not fill those gaps with an assumed overnight draw.
| Machine | Typical / peak consumption | Power supply or input | Manufacturer source |
|---|---|---|---|
| ResMed AirSense 10 | 53W / 104W | 90W adapter; 24V, 3.75A DC output | User guide, printed p. 16 |
| ResMed AirSense 11 | 56.1W / 73.2W | 65W adapter; 24V, 2.71A DC output | User guide, printed p. 22 |
| ResMed AirMini | 6.3W / 27W | 24V, 0.83A DC output | User guide, printed p. 24 |
| Philips DreamStation 2 | Not specified in the cited section | 100-240VAC, 50/60Hz, 2.0-1.0A input | User manual, printed p. 55 |
| React Health Luna G3 APAP (LG3600) | Not specified in the cited section | 100-240VAC, 50/60Hz, 2A maximum input | User manual, section 6 |
Sources checked October 15, 2026. Use the manual and approved accessories for your exact model and region. The ResMed technical-specification blocks do not identify a humidifier setting for their typical figures. Do not interpret them as a measured humidifier-off average, or infer the reason for a model-to-model difference.
The Three Numbers on a CPAP, and Which One to Use
Power-supply output rating: voltage multiplied by current describes the adapter's rated output. It does not tell you how many watt-hours the complete setup uses overnight. Keep input and output measurements separate; do not assume an AC system-consumption figure is the required DC-port current.
Typical consumption: a manufacturer reference for the specified system. It is a useful starting scenario when you lack a measurement, but it does not establish your average draw or a guaranteed battery reserve.
Peak consumption: useful when checking the power source's output requirements. Follow the device and accessory specifications for waveform, voltage, connector, and current as well as wattage. A sufficiently large battery does not establish electrical compatibility.
Measured overnight average is the figure that improves the runtime estimate. Measure watt-hours at the AC outlet feeding the machine's approved adapter, then divide by hours of use. That includes the adapter in the measurement. For VA-rated equipment, check the apparent-power limit too; watts and volt-amps are not interchangeable.
What Actually Sets the Draw
A heated humidifier, heated tube, pressure, ambient conditions, and standby time can change the energy budget. Use your normal prescribed setup when measuring it; changing therapy settings is not part of this sizing calculation. Our humidifier battery-drain guide explains the planning trade-offs.
DC operation needs a manufacturer-approved, model-specific converter. A power station's 12V socket is not automatically compatible with a CPAP's input. See the CPAP DC vs AC guide and the port wattage limits guide for the separate connection checks. The table below models AC operation only.
From Watts to Watt-Hours to Nights
What Battery Size Does Your CPAP Machine Wattage Require?
For an AC power station, our published method uses:
- Nightly energy = average watts x hours of use
- Required rated capacity = nightly Wh x nights / 0.85
- Usable energy = rated Wh x 0.85
- Estimated nights = usable energy / nightly Wh, rounded down to half nights
Apply 0.85 once, on the capacity side. The required-capacity figures below round up to whole Wh and contain no reserve allowance. Choose additional capacity for uncertainty, aging, temperature, standby time, and other loads; a calculated minimum is not a backup recommendation.
| AC planning scenario | Energy for 8 hours | One night: rated Wh, no reserve | Two nights: rated Wh, no reserve |
|---|---|---|---|
| AirSense 10 at published typical 53W | 424Wh | 499Wh | 998Wh |
| AirSense 11 at published typical 56.1W | 448.8Wh | 528Wh | 1,056Wh |
| Illustrative measured average of 30W | 240Wh | 283Wh | 565Wh |
The 30W row is a hypothetical input, not a claim about a particular machine or humidifier setting. A 500Wh station has 425Wh usable in this model: only 1Wh above the first row's nightly requirement. It leaves effectively no reserve. Use the runtime calculator for your measured draw and sleep length.
Compare Power Stations Against the Same Load
These examples use rated capacity and the same AC method. Prices are dated retailer records; Amazon listings can change. None is a manufacturer endorsement of a CPAP/power-station pairing.
| Station and Amazon price | Rated / usable capacity | Estimated nights at 53W | Estimated nights at 56.1W |
|---|---|---|---|
| Anker SOLIX C1000 Gen 2 (currently $699.99 · checked Oct 19, 2026 · see on Amazon) | 1,024 / 870.4Wh | 2 | 1.5 |
| Jackery Explorer 1000 v2 (currently $499.00 · checked Sep 21, 2026 · see on Amazon) | 1,070 / 909.5Wh | 2 | 2 |
| EcoFlow DELTA 2 Max (currently $1049.00 · checked Oct 19, 2026 · see on Amazon) | 2,048 / 1,740.8Wh | 4 | 3.5 |
How to choose: for one-night planning at either full-size machine's published typical draw, start by comparing the 1kWh models. For two nights with more energy headroom, compare the 2kWh option. The Jackery's two-night estimate at the higher load leaves only 11.9Wh in this model; do not treat the rounded night count as a comfortable reserve.
These are capacity calculations, not measured overnight runs. Actual AC efficiency varies, especially at light loads. Low-load inverter overhead and automatic output shutoff matter for a travel CPAP such as AirMini; its low typical wattage does not justify promising weeks from a large station. Confirm supported operation and output settings before relying on any backup. Broader choices are in our CPAP power-station buying guide.
How to Find Your Machine's Real Number
- Identify the exact model and approved adapter. Read the electrical requirements in its manual; do not use a different model's rating.
- Measure a representative night. A suitable plug-in energy meter between the AC source and approved adapter records Wh. Divide by elapsed hours to get average watts, including any standby time you intend to cover.
- Use that average in the calculator. Include every night between recharges and any other devices sharing the battery. Keep a reserve beyond the calculated minimum.
A reading taken at the CPAP's DC input is a different power path. It cannot be substituted into the AC calculation without considering the converter's losses.
FAQ
What is CPAP machine wattage?
It is the machine or system's power draw in watts. Average watts determine energy use over time; peak consumption and the manufacturer's electrical requirements help assess the power source. The adapter's output label is a separate specification, not an overnight measurement.
How many watts does a CPAP use per night?
Watts measure power; watt-hours measure the energy used over a night. Multiply average watts by hours. An illustrative 30W average over 8 hours uses 240Wh. Use the battery-sizing table above to account for the AC inverter loss once.
Does a CPAP use a lot of electricity?
Calculate energy from your own draw and hours rather than the adapter label. For example, 30W for 8 hours is 0.24kWh per night. Annual use at that same load is 87.6kWh; multiply by your electricity rate for cost. This is an example, not a measured CPAP result.
How many watts does a CPAP with a humidifier use?
There is no single figure for every model and setting. Check the exact manual and measure your normal setup. The typical figures in the manufacturer table do not specify a humidifier setting, so they should not be relabeled as a universal humidifier-on or humidifier-off draw.
What is the ResMed AirSense 10 wattage?
The linked ResMed user guide lists 53W typical and 104W peak system consumption, alongside a 90W adapter output rating. Those are different specifications. The typical figure gives a planning scenario of 424Wh over 8 hours; actual overnight energy use needs measurement.
What is the ResMed AirSense 11 wattage?
The linked ResMed user guide lists 56.1W typical and 73.2W peak consumption, alongside a 65W adapter. The typical figure gives 448.8Wh over 8 hours. It does not establish a particular humidifier setting or a guaranteed runtime.
How many amps does a CPAP draw on 12V?
Current equals power divided by voltage only for the power measured at that point. A 60W load at a 12V input would draw 5A, before any additional conversion losses. Do not divide a published AC consumption figure by 12V and call it the manufacturer's DC requirement. Check the approved converter's input specifications.
What size inverter does a CPAP need?
Follow the exact machine and approved adapter's power-source requirements, including waveform and peak demand. Battery capacity in Wh does not establish inverter compatibility. A USB-C power rating alone also does not establish the correct voltage, connector, or approved power path.
Can a 300Wh power bank run a CPAP all night?
It depends on the measured load and supported power path. With our AC planning factor, 300Wh gives 255Wh usable. At an illustrative 30W average, 8 hours needs 240Wh, leaving only 15Wh; at 40W, the same night needs 320Wh and exceeds that capacity. Do not assume a full night from the battery label alone.
What size battery do I need for two CPAP nights?
For AC operation, multiply average watts by hours per night and by two, then divide by 0.85 for rated Wh before adding a reserve. An illustrative 30W average over two 8-hour nights needs at least 565Wh rated, rounded up, before reserve. Check the calculator and the manufacturer's compatibility requirements before buying.
The Bottom Line
Use measured overnight energy when available, and the exact model's published consumption as a clearly labeled planning scenario when it is not. Check the power connection separately, leave capacity beyond the calculated minimum, and compare current offers after the arithmetic. The CPAP runtime comparison and runtime calculator extend the same method to other stations and sleep lengths.