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WATTMATRIX LAB BENCH // 230V 50Hz
WattMatrix
☕
WILL POWER YOUR CPAP MACHINE230V AC
35.2HRS
Continuous: 40W
Surge Peak: 65W

≈ 4.4 nights (8h/night) · Safe motor start buffer (98.6% margin).

Ready to Run
Motor Start Margin+4735W Safe Buffer(65W Peak / 4800W Max)

How long will an EcoFlow DELTA 2 Max run a CPAP machine?

CPAP machine running (65 W max) and start-up (90 W max) draw fit the EcoFlow DELTA 2 Max's 2,400 W continuous / 4,800 W surge ratings.

LOW LOAD
2.7DAYS

humidifier and heated tube off (15 W)

15 W31.17 W net
TYPICAL SPECNOMINAL
35.2HRS

standard pressure with humidifier active (40 W)

40 W58.17 W net
HIGH LOAD
24.0HRS

high pressure with HumidAir and heated tube at max (65 W)

65 W85.23 W net
TELEMETRY // PRIMARY READOUT230V AC
CALIBRATED RUNTIME
35.2HRS

≈ 4.4 nights (8h/night)

NET PACK DRAW
58.17W

System standby power: 15W (25.8% of total draw)

CONTINUOUS_LOAD_UTILIZATION2% (40W / 2400W)
APPLIANCE_DRAW40W RUN / 65W PK
SOURCE_LIMIT2400W CONT / 4800W PK
SOLAR_RECHARGE (1000W)2.69H (0.67D)
PARAMETER_SANDBOX // ENGINE v1.0.0

Live Load, Duty Cycle & Usage Simulator

40 W
MIN 7WNOMINAL 40WMAX 2000W
100%
5% INTERMITTENT50% CYCLING100% CONTINUOUS
8 h/night
1H / NIGHT8H OVERNIGHT24H CONTINUOUS
0 W
0W (OFF)200WMAX 1000W
OUTPUT_PATH
TEMPERATURE DERATE
CONTINUOUS
35.2HRS
OUTAGE SPAN
4.4nights
AVG LOAD
40W
PACK DRAW
58.17W
Stack CPAP machine with other devices on EcoFlow DELTA 2 Max in the Load BuilderOpen Builder →
HARDWARE_INTERFACE // ELECTRICAL AUDIT

EcoFlow DELTA 2 Max × CPAP Machine Electrical Interface

1. AC RECEPTACLE & PLUG MATCH
BS 1363 / Europlug (230V 13A Domestic) → DIRECT FIT

Provides 6× CEE 7/3 (230V) (120V 60Hz).

2. WAVEFORM & THD SENSITIVITY
PURE SINE WAVE // THD-SENSITIVE LOAD

Pure sine wave inverter output. Safe for sensitive medical electronics and variable-speed motors.

3. STARTING SURGE (MOTOR INRUSH) MARGIN
65W TYP (90W MAX) VS 4800W LIMIT

Inductive motor/compressor load with 1.6× starting surge (motor inrush) (98.6% worst-case surge margin).

4. UPS SWITCHOVER & EXPANSION
UPS: UPS (20MS) · EXPAND: UP TO 6144WH

Wall AC fast charge at up to 1800W (66m to 80%, 80m to 100%).

PHYSICS // TRANSIENT DRAW ENVELOPE

Dynamic Inrush Surge Curve (Locked Rotor Amps vs Steady State)

SAFE INRUSH HEADROOM (+4735W BUFFER)
0ms250ms500ms750ms1000ms0W2s Surge Limit (4800W)4800WContinuous Rating (2400W)2400WInrush (LRA): 65WRunning (FLA): 40W

Safe envelope verified: Starting surge (65W) remains comfortably below the 4800W surge trip line, with steady-state operation settling into the safe continuous zone at 40W.

LAB_RECORDS // EMPIRICAL OBSERVATIONS

Field Engineering Quirks & Operational Failure Modes

Hardware Bench Constraints (EcoFlow DELTA 2 Max)
  • ›X-Boost engages automatically above 2,400 W and runs resistive loads up to 3,400 W at reduced voltage. EcoFlow says it's meant for heating loads, not voltage-sensitive devices, and it's unavailable during wall-charging bypass.
  • ›UPS: switches to battery within 20 ms per the manual and product page (EcoFlow's FAQ says 30 ms). EcoFlow says it is not 0 ms and not suitable for servers or workstations.
  • ›The AC output switches off after 12 hours with no load; set the app's AC timeout to 'Never' for intermittent loads.
  • ›Two 500 W solar inputs give 1,000 W combined; EcoFlow's 43-minute 0–80% figure needs 1,800 W wall charging plus solar at the same time.
  • ›The car socket and both DC5521 ports share one 126 W budget.
  • ›All six AC outlets are 20 A T-slot NEMA 5-20R.
Cycle Physics & Dwell Behavior (CPAP Machine)
  • ›Turning off the heated humidifier and ClimateLineAir heated tube cuts power draw by more than half (from 40–65 W down to ~15 W), more than doubling battery runtime.
  • ›Running from a power station's 12 V car socket via ResMed's Air11 DC/DC Converter (part 39231) avoids turning on the station's AC inverter and its ~15 W idle drain.
  • ›The AirSense 11 uses a 24 V DC input with a proprietary 3-pin sense pin, so it requires the official Air11 DC/DC converter rather than a passive 12 V barrel cord.
KNOWLEDGE_BASE // VERIFIED QA

Frequently Asked Questions: EcoFlow DELTA 2 Max & CPAP Machine

How long will an EcoFlow DELTA 2 Max run a CPAP machine?

About 35 hours on AC power, with the CPAP machine averaging 40 W (standard pressure with humidifier active (40 W)). The EcoFlow DELTA 2 Max then draws about 58 W from its battery, including 15 W for the inverter itself. Best case: about 66 hours (humidifier and heated tube off (15 W)). Worst case: about 24 hours (high pressure with HumidAir and heated tube at max (65 W)). At 8 hours a night, that's about 4.4 nights.

Is it better to run the CPAP machine from DC on the EcoFlow DELTA 2 Max?

Yes. Using the ResMed Air11 90 W DC/DC Converter (part 39231) on the EcoFlow DELTA 2 Max's 12 V car socket, the CPAP machine runs about 52 hours instead of 35 hours on AC, 49% longer, because it skips the inverter's conversion loss and its 15 W idle draw. That's 6.6 nights instead of 4.4 nights.

Why isn't the runtime just 2,048 Wh ÷ 40 W?

That simple division gives 51 hours, but the EcoFlow DELTA 2 Max's inverter draws about 15 W whenever its AC outlets are on. At this light load that's 26% of everything the battery supplies, and inverter conversion losses take a further share. EcoFlow doesn't publish an idle figure and we haven't found an independent measurement, so this uses our 15 W estimate.

How long does the EcoFlow DELTA 2 Max take to recharge?

On wall power: about 66 minutes to 80% and 80 minutes to full (EcoFlow figures). With its maximum 1,000 W of solar input connected, expect about 800 W in full sun, so a full recharge takes roughly 2.7 hours of full sun, so it can refill in a single day with 4 peak sun hours.

Can the EcoFlow DELTA 2 Max keep a CPAP machine running during a power cut?

It can act as a backup supply: with the CPAP machine plugged into the EcoFlow DELTA 2 Max and the EcoFlow DELTA 2 Max plugged into the wall, it switches the CPAP machine to battery in about 20 ms when the grid fails (EcoFlow calls this UPS mode).

AUDIT_LOG // DATA PROVENANCE & CITATIONS
NODE: ecoflow-delta-2-max/cpap-machineSYSTEM HASH: 0x7D96361C28B4VERIFIED TIMESTAMP: 2026-10-21T00:00:00Z
SOURCE_CITATIONS // ECOFLOW DELTA 2 MAX (5)
LOAD_CITATIONS // CPAP MACHINE (3)

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