Continuous vs Pulse Dose Oxygen Concentrator: The Real Power Draw Numbers

The Actual Difference, Briefly

Pulse dose delivers a burst of oxygen only when a sensor detects the start of an inhale — nothing flows while you exhale or pause between breaths. The concentrator’s compressor works in short bursts matched to your breathing rate, not constantly.

Continuous flow delivers oxygen at a fixed rate measured in liters per minute, running whether you’re inhaling, exhaling, or holding your breath. The compressor runs the whole time the unit is on, not just when you’re actively breathing in.

That difference — bursts matched to breathing versus constant output — is also the entire reason the power draw is so different between the two. A compressor that only works during roughly half of your breathing cycle (the inhale) uses meaningfully less electricity than one running nonstop.

Your doctor decides which mode you need based on how much oxygen you require and how consistently, not based on power consumption — this article is about what powering your specific device actually looks like, not a substitute for that conversation.

The Real Power Draw Numbers

Concentrator Type	Typical Power Draw	Example Models
Portable, pulse dose	40–130W	Inogen One G5 (~40–60W), CAIRE Freestyle Comfort (~50–90W)
Portable, continuous flow	120–300W	Philips SimplyGo (~120W idle, ~150W charging), CAIRE Eclipse 5 (~170–250W)
Stationary, 5-liter continuous	200–350W	Inogen At Home (~100W @ 2 LPM, ~275W max), CAIRE Companion 5 (~280W @ 2 LPM, ~350W max)
Stationary, 10-liter continuous	450–800W	Larger clinical-grade units, commonly ~585W typical

A few things worth pulling out of this table rather than reading past it:

The gap between pulse and continuous isn’t small. Even comparing two portable units, continuous flow can draw two to three times what pulse dose draws for a similar-sized machine. That’s the direct cause of the battery-life gap covered in my portable oxygen concentrator battery life guide — continuous-flow portables consistently run shorter on the same battery, and this is why.

Flow rate matters within each mode, too. Going from 1–2 LPM to 5+ LPM on a continuous-flow unit typically adds 30 to 50% to the power draw at the low end of the range. A concentrator “rated” at a given wattage is usually rated at a specific, often low, flow setting — check which flow rate the number applies to before you size anything around it.

Rated wattage and actual wattage aren’t the same thing either. Manufacturer power ratings are typically measured at steady-state operation. Real draw fluctuates with flow setting, ambient temperature, and how hard the compressor is working at that moment — treat the spec sheet number as a reasonable planning estimate, not a guaranteed ceiling.

The Number Nobody Mentions: Startup Surge

Every compressor-based device — an oxygen concentrator included — draws more power for the first second or two after it switches on than it does once it’s running. This is called startup surge or inrush current, and it happens because the compressor motor needs extra current to overcome its own resting inertia before it settles into steady operation.

For an oxygen concentrator, that surge commonly runs 1.5 to 2 times the running wattage, for roughly one to three seconds. A stationary 5-liter unit rated at 350 watts running might briefly pull 525 to 700 watts at startup. A continuous-flow portable rated at 200 watts running might briefly pull 300 to 400.

This matters enormously for anyone sizing a power station or generator, and it’s the single most common mistake I see: buying backup power sized to the running wattage on the box, then having it shut down or fail to start the concentrator at all — because the power station’s continuous rating covers the running load fine, but its surge rating doesn’t cover that first-second spike. Shopping for backup power for a continuous-flow unit specifically? Look for a power station whose surge rating is comfortably above your concentrator’s running wattage — not just a continuous rating that matches it.

This is also part of why pure sine wave output isn’t optional for this equipment. A compressor motor is a far more demanding load than something like a phone charger, and modified sine wave power can cause a compressor to run hotter, less efficiently, or trip an internal protection circuit — on top of the surge issue, not instead of it.

Sizing Backup Power for Either Mode

For pulse dose units, sizing is fairly forgiving — the low running wattage and modest surge mean most mid-size power stations handle them without much planning. For continuous flow, especially a stationary 10-liter unit, both the running wattage and the surge matter, and it’s worth checking both numbers against the power station’s specs rather than just one.

The free Oxygen Concentrator Runtime Calculator on this site runs this math for your specific model, flow setting, and delivery mode rather than the general ranges above. For the fuller picture on pairing a concentrator with backup power for outages specifically, my battery for oxygen concentrator guide covers that end to end.

FAQs

Does pulse dose use six times less power than continuous flow?

Some sources cite a ratio that large, but it varies a lot by model and flow setting — the more consistent, broadly-supported range is two to three times less power for a comparable unit, not a fixed six-to-one ratio. Treat any single ratio as a rough planning figure, not a guarantee for your specific device.

Can I run a continuous-flow concentrator on a small portable power station?

For a portable continuous-flow unit (120–300W), a mid-size power station usually works, provided its surge rating clears your unit’s startup spike, not just its running wattage. For a stationary 10-liter unit, you’re generally looking at a larger power station built for higher continuous and surge loads.

Why does my concentrator’s power draw change even at the same setting?

Ambient temperature, altitude, and how hard the compressor is working at that instant all cause real-world draw to fluctuate around the rated number — this is normal and expected, not a sign of a problem.

Is pulse dose ever available for a stationary concentrator?

No — pulse dose is a portability feature built around detecting your breathing through a cannula sensor, which only makes sense on a device you’re wearing or carrying. Stationary units are continuous flow only.

Bottom Line

Pulse dose draws less power because it only works during roughly half your breathing cycle; continuous flow draws more because the compressor never stops. In real numbers, that’s 40 to 130 watts for portable pulse dose versus 120 to 300 for portable continuous flow, and considerably more for a stationary unit. The number that actually determines whether your backup power works, though, is startup surge — 1.5 to 2 times the running wattage for the first second or two — and it’s the detail most comparisons of these two modes skip entirely. Size backup power around both numbers, not just the one on the spec sheet.

For runtime specifics by model, see my portable oxygen concentrator battery life guide, and for full outage-backup planning, my battery for oxygen concentrator guide.