SiriusWatts

How long will the EcoFlow River 2 Pro run a cpap machine?

Will the EcoFlow River 2 Pro run a cpap machine?

Yes — the River 2 Pro runs a cpap machine comfortably

Its 800W continuous output easily covers the 40W draw, with 1600W of surge on tap for startup.

Estimated runtime
about 15 hours
on a single full charge
Est. usable (AC): 587 Wh
Appliance draw: 40 W
Continuous output: 800 W

How we calculated this

We start from the EcoFlow River 2 Pro's 587 Wh of estimated usable energy at the outlet — its 768 Wh rating, derated for a safe depth of discharge and ~15% inverter loss — then divide by the cpap machine's 40W draw:

587 Wh ÷ 40 W ≈ 14.7 hours

Heads up: a cpap machine is a motor/compressor load that spikes 2–3× on startup. The EcoFlow River 2 Pro's 800W continuous / 1600W surge output has plenty of headroom for that spike.

Real-world runtime varies with temperature, cable losses, and how hard the appliance actually cycles. Treat this as a solid estimate, not a guarantee.

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