CPAP Power Guide 2026: Every Major Brand, Runtime Tables, and Best Generators
Table of Contents
How Long Will a Solar Generator Run Your CPAP?
The short answer: a lot longer than most people think. A ResMed AirSense 10 without humidifier draws 37W on average. On a 1000Wh solar generator, that's roughly 23 hours of therapy — enough for two full nights of sleep on one charge. With the humidifier running at full power (95W), that same unit lasts about 9 hours. The humidifier is the variable that changes everything, and it's the first setting to disable when power conservation matters.
This guide covers every major CPAP model with actual wattage figures, a full runtime table across generator sizes, and specific product recommendations based on how many nights of backup you need.
CPAP Power Draw by Model: Real Wattage Numbers
These figures are drawn from manufacturer specifications and independent measurements. "Average" wattage reflects typical therapeutic use at moderate pressure settings. Actual draw varies with prescribed pressure and breathing pattern.
| CPAP Model | Type | Avg Watts (No Humidifier) | Avg Watts (Max Humidifier) |
|---|---|---|---|
| ResMed AirSense 10 | CPAP/APAP | 37W | 95W |
| ResMed AirSense 11 | CPAP/APAP | 30W | 90W |
| ResMed AirMini | Travel CPAP | 12W | N/A (no humidifier) |
| Philips DreamStation 2 | CPAP/APAP | 28–45W | 65–90W |
| BMC RESmart | CPAP/APAP | 30–50W | N/A (varies by model) |
| BiPAP (any brand) | BiPAP | Add 15–25W to CPAP equivalent | Add 15–25W to humidifier figure |
The AirSense 11 is measurably more efficient than the AirSense 10 — 30W vs 37W without humidifier. That 7W difference adds up to roughly 2 extra hours of runtime per charge on a 1000Wh unit. If you're on an older machine and prioritize power backup, this is one legitimate reason to consider upgrading.
Runtime Table: CPAP Hours by Generator Capacity
Calculations use a 0.85 efficiency factor for inverter losses when running on AC. DC cable usage (see next section) eliminates most of this loss.
Without Humidifier
| CPAP Model | 300Wh | 512Wh | 1024Wh | 2048Wh | 3600Wh |
|---|---|---|---|---|---|
| AirSense 10 (37W) | 6.9 hrs | 11.8 hrs | 23.5 hrs | 47 hrs | 82.7 hrs |
| AirSense 11 (30W) | 8.5 hrs | 14.5 hrs | 29 hrs | 58 hrs | 102 hrs |
| AirMini (12W) | 21.3 hrs | 36.3 hrs | 72.5 hrs | 145 hrs | 255 hrs |
| DreamStation 2 (35W avg) | 7.3 hrs | 12.4 hrs | 24.8 hrs | 49.6 hrs | 87.4 hrs |
| BiPAP (55W avg) | 4.6 hrs | 7.9 hrs | 15.8 hrs | 31.6 hrs | 55.6 hrs |
With Humidifier at Maximum Setting
| CPAP Model | 300Wh | 512Wh | 1024Wh | 2048Wh | 3600Wh |
|---|---|---|---|---|---|
| AirSense 10 (95W) | 2.7 hrs | 4.6 hrs | 9.2 hrs | 18.3 hrs | 32.2 hrs |
| AirSense 11 (90W) | 2.8 hrs | 4.8 hrs | 9.7 hrs | 19.4 hrs | 34 hrs |
| DreamStation 2 (77W avg) | 3.3 hrs | 5.7 hrs | 11.3 hrs | 22.6 hrs | 39.7 hrs |
| BiPAP with humidifier (115W avg) | 2.2 hrs | 3.8 hrs | 7.6 hrs | 15.1 hrs | 26.6 hrs |
The DC Cable Advantage: 30% More Runtime
Most CPAP users plug into AC (120V wall outlet). When running from a solar generator, that means: DC battery → inverter converts to AC → CPAP power supply converts back to DC. Every conversion loses energy — typically 15–18% at each stage.
Running a CPAP via DC cable directly from a 12V output eliminates the inverter stage entirely. The result: roughly 20–30% more runtime on the same battery capacity. The EcoFlow DELTA 2 and DELTA Pro series both have a 12.6V DC car port that works with compatible CPAP DC cables. The AirSense 10 and 11 accept DC power via a specific ResMed power supply cable (sold separately) or third-party DC cables for specific generator brands.
Before buying, verify that your CPAP model has a DC input option and confirm compatibility with your generator's DC output voltage. Most ResMed machines accept 12–24V DC. Running via DC at 12W instead of 37W AC (with humidifier off and AirMini model) on a 512Wh unit gives you 36+ hours instead of 11.8 — a transformative difference for camping or extended outages.
The Humidifier Decision
The heated humidifier on a CPAP machine is a major power draw. The AirSense 10's humidifier alone draws approximately 58W on top of the machine's 37W base draw — more than doubling consumption. If you're on battery power, this is the first thing to reduce or disable.
Strategies to manage humidifier power draw:
- Reduce humidifier level: Setting from 5 to 3 reduces power draw by roughly 30–40%.
- Use a HumidX: The ResMed AirMini uses waterless humidification via a HumidX filter, adding virtually zero watts while still providing moisture. If you travel and need humidification, the AirMini with HumidX is the most power-efficient option available.
- Disable during extended outages: Most CPAP users adapt to no humidification within a few nights. Dry air can cause throat irritation, but saline nasal spray is an effective interim solution.
Recommended Solar Generators by Use Case
1 night of backup (no humidifier): A 300–512Wh unit handles most CPAP machines for a single night. The EcoFlow DELTA 2 Min (256Wh) or any budget 300Wh unit works. For the most efficient small option, check the best solar generators for CPAP guide. Check price on Amazon.
2–3 nights of backup (no humidifier): A 1024Wh unit provides 23+ hours for AirSense 10 users — 3 full nights with margin. The EcoFlow DELTA 2 (1024Wh) with its DC output for cable charging is the top pick here. See the EcoFlow DELTA 2 review. Check price on Amazon.
5+ nights or with humidifier: A 2048Wh unit provides 18+ hours with humidifier running — covering most multi-day outages. The EcoFlow DELTA Max 3 or Bluetti AC200L fit here. Check price on Amazon.
Extended outage or BiPAP users: BiPAP draws 15–25W more than equivalent CPAP. For reliable extended backup, a 3600Wh unit like the EcoFlow DELTA Pro provides 50+ hours for most BiPAP users without humidifier. Check price on Amazon.
Common Mistakes When Running CPAP on Battery
- Leaving the humidifier on full: Immediately cuts runtime by 60%. This is the single most impactful change you can make.
- Not having a DC cable: Running via AC inverter wastes 20–30% of your battery. DC cable compatibility should be confirmed before any camping or backup planning.
- Buying a unit that's too small: A 300Wh battery for an AirSense 10 with humidifier provides only 2.7 hours — not enough for a single night. Know your machine's actual wattage before buying.
- Not testing before relying on it: Test your full setup — generator, cable, and CPAP — at home before you need it during an outage or on a camping trip. Some DC cable combinations have compatibility issues that appear only when the devices interact.
Frequently Asked Questions
How long will a solar generator run a ResMed AirSense 10?
A ResMed AirSense 10 without humidifier draws 37W on average. On a 1024Wh solar generator (at 0.85 efficiency), that's approximately 23.5 hours — nearly 3 full nights. With the humidifier at maximum (95W), runtime drops to about 9.2 hours on the same unit. Disabling the humidifier is the single most effective way to extend CPAP runtime on battery.
What is the best solar generator for CPAP use?
For 1–2 nights without a humidifier, a 512–1024Wh unit like the EcoFlow DELTA 2 is ideal and has DC output for efficient cable charging. For 3–5 nights or humidifier use, the EcoFlow DELTA Max 3 (2048Wh) provides 18+ hours even with humidifier. For BiPAP users needing extended backup, the EcoFlow DELTA Pro (3600Wh) provides 50+ hours of BiPAP runtime without humidifier.
Does a CPAP need a pure sine wave inverter?
Yes. CPAP machines require a pure sine wave power source for safe, reliable operation. Modified sine wave inverters can cause CPAP machines to overheat, perform erratically, or fail prematurely. All major solar generators (EcoFlow, Jackery, Bluetti, Anker SOLIX) use pure sine wave inverters, so this is not an issue with any reputable brand's unit.
Can I run my CPAP from a car battery or 12V DC?
Yes, with the appropriate DC cable. Most ResMed and Philips machines accept 12–24V DC input via a specific cable. The EcoFlow DELTA series provides a 12.6V DC car port. Running via DC skips the inverter conversion, saving 20–30% of battery capacity compared to running via the AC outlet. Verify your specific CPAP model's DC compatibility before purchasing a cable.
How much power does a CPAP use per night?
An average CPAP session of 8 hours at 37W (AirSense 10, no humidifier) consumes approximately 296Wh. With humidifier at 95W, that same 8-hour session uses 760Wh. A travel CPAP like the ResMed AirMini at 12W consumes only 96Wh per 8-hour night — small enough to run multiple nights on a 300Wh unit.
Will turning off the CPAP humidifier affect my therapy?
Turning off the humidifier reduces comfort but does not affect the therapeutic air pressure of CPAP therapy. Some users experience dry mouth, nasal dryness, or mild throat irritation without humidification. Saline nasal spray before sleep and drinking water before bed can mitigate dryness. Many users adapt within a few nights, especially in higher-humidity environments.
How long will a solar generator run a BiPAP machine?
BiPAP machines draw 15–25W more than equivalent CPAP machines due to the pressure differential delivery. An average BiPAP at 55W (no humidifier) on a 1024Wh solar generator will run approximately 15.8 hours. With humidifier at 115W average, that drops to about 7.6 hours. A 2048Wh unit provides 30+ hours of BiPAP runtime without humidifier, sufficient for multi-night backup.
Is the ResMed AirMini good enough for home backup use?
The AirMini is excellent for power backup because of its 12W draw — roughly one-third of a standard CPAP's consumption. However, it lacks a full humidifier chamber (using a waterless HumidX filter instead) and has a smaller, less comfortable hose. For occasional emergency backup, it's outstanding. For nightly home use, most users find the full-size AirSense 10 or 11 more comfortable.
