Does a BiPAP use more power than a CPAP?

BiPAP vs CPAP power draw

Yes. A typical BiPAP draws about 12W against a CPAP's 8W without humidification — 50% more, which makes runtime about a third shorter. With the humidifier on the gap narrows to roughly 50W against 40W, because the heating element dominates both.

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Bluetti Elite 100 V2
The bilevel tier
At 1,024Wh a bilevel machine still gets about 65 hours dry — eight nights. The smaller 300Wh class drops to roughly two nights on a BiPAP, which is where it stops being an outage battery.
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Power-draw figures for the machines below are provisional estimates, not yet our own meter readings. See how we test.

A bilevel machine cycles between two pressures instead of holding one, so the blower works harder. The interesting part is that the penalty is large when you run dry and small when you run humidified — because once a heating element is in the circuit, it swamps the difference.

The draw figures

At a typical therapy pressure, comparing a ResMed AirCurve 10 bilevel against an AirSense 11 CPAP:

Typical running draw
Machine	Humidifier off	Humidifier on
CPAP (AirSense 11)	8W	40W
BiPAP (AirCurve 10)	12W	50W
Difference	+50%	+25%

Provisional estimates at around 10 cmH₂O, not yet meter-verified by us — see How We Test. Bilevel draw varies more with the pressure difference between IPAP and EPAP than fixed-pressure CPAP does.

What it costs in runtime

Converted to hours on the two most common battery sizes:

Runtime per charge, from the AC outlet
Battery	CPAP dry	BiPAP dry	CPAP humid.	BiPAP humid.
292Wh	27.9 h	18.6 h	5.6 h	4.5 h
1,024Wh	97.9 h	65.3 h	19.6 h	15.7 h

90% usable capacity, 85% inverter efficiency.

The practical rule

Running dry, size up by about a third. Where a CPAP user would buy 292Wh for three nights, a BiPAP user needs closer to 450Wh for the same three.

Running humidified, the difference barely registers — about 20% — because the humidifier is doing most of the drawing in both cases. The decision that dominates is still the humidifier, not the machine type.

Bilevel draw also varies more between users than CPAP does. A large gap between inhale and exhale pressure costs more than a small one, so your own machine is worth measuring.

How many watts does a BiPAP use?: Roughly 12W without humidification and roughly 50W with the heated humidifier at a mid setting, at a typical pressure. Higher pressure support raises both.
Will my CPAP battery run a BiPAP?: Yes, but for about a third less time when running dry. A 95Wh battery that gives a CPAP about 9 hours gives a bilevel machine about 6.
Does an ASV or ventilator draw more than a BiPAP?: Generally yes — more adaptive machines do more work. Check your own model's plate rating, and measure it if runtime matters to you.

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