Our answer
On our planning profile the BLUETTI AC70 runs a CPAP machine for about 17 hours, or 14 hours if you keep a reserve back.
The checks behind this answer
Stored energy is the final check, not the first. Voltage, continuous output, and startup demand must clear before runtime means anything. Missing published evidence stays marked unverified instead of being treated as a pass.
| Check | Result | Why |
|---|---|---|
| Voltage | Clears | A CPAP machine runs on 120V and the BLUETTI AC70 supplies 120V AC. |
| Continuous output | Clears | A 35W running load sits inside the 1,000W continuous rating, leaving about 2757% headroom. |
| Startup demand | Clears | The 60W start is covered by continuous output alone, so no surge rating is needed. |
| Inverter self-consumption | Unverified | This is a long, low-power load, so the inverter's own draw materially changes the answer. That figure is not published for this station. |
How the number is built
A battery holds back some of its rated capacity, and converting to household AC costs more on top. Of the 768Wh rated here, roughly 608Wh reaches the outlet under a conservative planning model.
That energy meets an average load of 35W, which applies a 100% duty cycle to a 35W running draw. Holding back a 20% reserve for battery age, cold, and a longer outage leaves 14 hours. These are calculations, not measurements from a test.
What we could not verify
These gaps are in the published evidence, not in the arithmetic. Each one is a reason to check before you depend on this pairing.
- Inverter self-consumption is not published, and it matters more than the appliance load on a run this long.
Before you rely on this
These limits decide whether this appliance belongs on a portable battery at all.
- This page is planning information, not medical advice, and nothing here is a guarantee of therapy continuity.
- Use only the power supply or DC converter that your device manufacturer approves for your model.
- If an interruption in therapy would be dangerous for you, discuss a backup plan with your clinician or equipment supplier rather than relying on a calculation.
Replace our assumptions with your own
Heated humidification and heated tubing can multiply the energy a CPAP uses overnight. Turning both off is the single largest change you can make to backup runtime, and it is a decision to make with your clinician, not a spreadsheet.
Check your device manual for its rated consumption at your prescribed pressure, then meter a full night with your actual humidifier setting.
Continue through this cluster
Use the next page that answers your unresolved constraint
Evidence used on this page
Important fields are tied to a specific source. Manufacturer claims, government guidance, calculations, and planning assumptions remain separate.
- AC70 published specifications
BLUETTI US
Capacity, output, surge, chemistry, cycle life, solar input, weight, UPS, expansion support, and warranty checked.
official product page
Device-specific battery tables, inverter guidance, and the energy difference humidification makes.
official support
- Calculation and compatibility methodology
Power Station Station
Defines the capacity, efficiency, reserve, duty-cycle, voltage, continuous-output, and startup checks applied across the site. Planning defaults are visible on every page that uses them.
planning assumption