Camping With a CPAP: Battery Math for a Full Night

In a hurry? A CPAP with the humidifier turned off draws roughly 25–45 watts at typical prescribed pressures; with the humidifier on it climbs to 55–90. That means a 300Wh portable power station is a single-night, humidifier-off solution — about 7 to 8.5 hours of therapy on a 292Wh station at 30W, or 6 on the same station at 40W. For a second night you either add a 100W solar panel, drop to a travel CPAP, or step up to a 500Wh+ station.

Sleep apnea is one of the most common reasons people quietly stop camping. Nobody wants to be the one who has to drive home at 6 a.m. because the machine died at 3. The good news is that the power problem is entirely solvable — and it is smaller than most guides make it sound, because almost every published "you need 1,000Wh" figure assumes you are running the heated humidifier all night.

This is the math, by machine and by setting, so you can size the battery once and stop thinking about it. If you are the one organizing a trip that spans three generations — the grandparent with the CPAP, the kids, the dog — our multigenerational camping guide covers the rest of that trip, and the camping for seniors guide covers the sleep-system side of it.

How Much Power Does a CPAP Actually Use?

CPAP draw is not one number. It is a range set by three things: the machine, the pressure you are prescribed, and whether the humidifier and heated hose are on.

Two reference points behind that table. ResMed rates the AirSense 10's power supply at 90W (24V DC, 3.75A) and the AirSense 11's at 65W — the 10 genuinely draws more in every configuration, which matters because most used and hand-me-down machines are AirSense 10s. And field measurements at typical pressures with the humidifier off cluster around 35–45W, not the peak on the label.

The practical translation: the machine you already own, with the humidifier off, is roughly a 40-watt device. That is a lightbulb. It is not a space heater.

One more number worth knowing: the AirSense 10 has no native DC input port — DC adapters connect to the same barrel connector the AC brick uses, and the adapter does the 12V-to-24V conversion for you. The AirSense 11 does have a native DC port. This detail decides whether you can skip the inverter entirely (more on that below), and it is the single most common thing people get wrong when they buy a DC cord for the wrong generation of machine.

The Humidifier Is the Whole Ballgame

The heated humidifier is not a side feature. It is a heating element, and it is the largest single variable in your overnight power budget.

• Humidifier off: draw is the blower motor alone — roughly 30–45W at typical pressure.
• Level 1–2: the heating element adds about 15–25W.
• Level 3–4: adds up to 35W on top of the motor.
• Heated hose (ClimateLine-class): another 15–20W on top of that.

A night at 40W draws about 320Wh. The same night with the humidifier at level 2 and a heated hose draws about 520Wh. Same machine, same sleep, 60% more battery.

For camping, turning the humidifier off is the highest-leverage change you can make, and it does not gut your therapy: the American Academy of Sleep Medicine's position is that humidification is a comfort feature, not a therapy requirement. What you may notice is a dry mouth or nose, especially in cold, dry fall air.

If dryness is the problem, work the problem in this order before you spend money on a bigger battery:

1. Drop the humidifier to level 1, not off. That is roughly 15W — usually under 60Wh for a night.
2. Use pass-through humidity. A pan of water near the tent's heat source, or camping somewhere humid, does more than people expect.
3. A heat-and-moisture exchanger (HME) — the small passive filter many travel CPAPs ship with — recycles some exhaled moisture without drawing a watt.
4. Accept dry and drink water in the morning. Zero watts, and the honest answer for a one-night trip.

Battery Sizing: One Night, a Weekend, a Week

Here is where the published tables and the sticker on the box disagree, and it is worth being blunt about it: a power station's watt-hour rating is battery capacity, not what comes out of the AC outlet. The inverter loses about 10–15% converting DC to AC. So a 292Wh station delivers roughly 250Wh to a CPAP through its AC outlet, and roughly 270Wh through a DC adapter.

Add a 15% buffer if you are camping below 50°F: cold, denser air raises motor load, and lithium batteries lose usable capacity in the cold as well. Add another buffer if the battery is more than three years old.

That table is why the honest recommendation for most tent campers is not "buy the biggest box." It is turn the humidifier off, and size for 300–450Wh. A 300Wh station covers a single night at moderate pressure with margin. Two nights without recharging is a 600Wh+ purchase, which is a different price bracket entirely — and for a family weekend, a 300Wh station plus a foldable solar panel is usually cheaper than one big station and keeps working trip after trip.

Which Station Actually Fits a Camping Trip

Our picks below are sized for tent and car camping. Read the runtime column, not the marketing copy — the numbers are computed at 85% inverter efficiency, humidifier off at 40W unless noted. If you want the wider buying logic across watts, ports and solar input, the portable power station camping guide has the full comparison.

Jackery Explorer 300 — 292Wh, $199

The Explorer 300 is the default answer for one camper with a CPAP: 292Wh, 300W continuous AC (600W surge), pure sine wave, LiFePO4 rated for 2,000+ cycles, and 7.1 pounds with a handle. Pure sine wave matters here — CPAP power bricks are electronics, not motors, and modified sine inverters are a known source of buzzing and dropped therapy.

Runtime for a CPAP: about 7.3 hours at 30W, 5.5 hours at 40W, 3.5 hours at 60W. In practice that is a comfortable full night with the humidifier off at pressure 8–10, and a marginal one at pressure 12–15. It also runs a phone, a headlamp and a string of lights on the same charge.

EcoFlow RIVER 2 — 256Wh, $169

The RIVER 2 is the cheaper, faster-charging option: 256Wh, 300W AC, LiFePO4 rated for 3,000+ cycles, and a 0–100% wall recharge in about 60 minutes — which is the real advantage on a road trip where you are topping up at a rest stop or a friend's house between legs.

Runtime for a CPAP: about 6.4 hours at 30W, 4.8 hours at 40W, 3.2 hours at 60W. If your pressure is in the 8–10 range and the humidifier is off, this is a full night for $30 less than the Jackery. If you are at 12+, it is not.

Anker SOLIX C300 — 288Wh, $329.99

The SOLIX C300 is the pick when the same box has to charge a laptop: 288Wh, 300W AC, a 60W USB-C PD port, and a 55-minute wall recharge. Runtime for a CPAP is essentially the Jackery's (7.2 hours at 30W, 5.4 at 40W) — you are paying for the USB-C PD and Anker's build, not for more therapy hours.

EGO Power+ 3000W Station — the basecamp and RV route

The EGO Nexus ($499) is a different class of machine: 3,000W of output that runs off EGO's 56V ARC Lithium packs, so its total capacity depends on which batteries you already own. It is not something you carry into a tent — it is what makes a CPAP plus a 12V fridge plus lights a non-issue at an RV site or a family basecamp, and it doubles as home backup. If you are car camping with a trailer, this is the honest answer; if you are in a dome tent, it is not.

Jackery SolarSaga 100W — how you get the second night

A 100W folding panel ($179) plugs straight into the Explorer 300's DC input with no adapter. Real-world output is 50–70W in decent sun with the panel angled, which means roughly 200–300Wh per day — one CPAP-night's worth of recharge, with some left over for phones and lights. That is what turns a one-night station into a multi-night setup: sleep, then recharge while you hike. The camping solar guide has the panel-angle and shading rules that decide whether you actually get that yield.

DC Adapter vs the AC Brick: A Free 15% of Runtime

This is the most under-used trick in CPAP camping, and it costs $20–40 for most machines.

Inverter route (what most people do): battery DC → inverter to 120V AC → the CPAP's own power brick back down to 24V DC. Two conversions, each losing 8–15%.

DC direct route: battery 12V → a 12V-to-24V DC adapter → the machine. One conversion, losing 5–10%.

At 40W over eight hours, the inverter route wastes 30–50Wh compared with DC direct. On a 292Wh station that is 45 to 75 extra minutes of therapy — real, but not the difference between a night and no night. Where it matters is a 256Wh station at pressure 12: DC direct turns a 4.8-hour night into something closer to 5.5.

Two cautions. First, the adapter must match your machine's generation and connector — an AirSense 10 adapter will not run an AirSense 11, and the AirSense 10 needs a 24V output, not 12V. Second, buy the adapter from a seller who states the output voltage and the model compatibility explicitly; a generic 12V car cord that happens to fit the barrel is not the same thing.

Solar at Camp: What a Panel Really Delivers

A panel's rating is a lab number at 25°C with the sun directly overhead. Expect 50–70% of nameplate in real camping conditions: morning and evening sun, angled panels, haze, tree cover.

• 100W panel: 50–70W real output, 200–300Wh on a good day — enough to recharge a 300Wh station for a second CPAP night with margin.
• 200W panel: 100–140W real output, 400–600Wh on a good day — a weekend of CPAP plus lights and phones without rationing.
• RV or trailer with a roof panel and a house battery: this is the answer that needs no math at all. If you are camping with hookups, your CPAP is a non-issue; if you are boondocking with a 100Ah lithium house battery, you have about 1,000Wh usable at 80% depth of discharge — three CPAP nights plus normal loads.

One rule: recharge during the day, not at night. Panels do nothing while you sleep, and a station that reads 40% at 7 a.m. will not fill itself by bedtime unless you actually set the panel out before you leave for the trail.

Four Camping Setups, and Where the Machine Goes

Tent. Run the machine off the station inside the tent, with the station outside the sleeping bag but inside the tent — below about 40°F a lithium battery loses meaningful usable capacity, and a cold battery at 3 a.m. is the most common way a correctly-sized setup fails. Keep the machine off the tent floor (a folded pad or the top of a duffel), route the hose so it does not kink, and expect some condensation in the hose on a cold night — that is normal, and a hose cover solves most of it.

Car and minivan. This is the easiest setup there is: a 12V DC adapter plus a running vehicle, or a station charged from the car's 12V socket while you drive. Do not run a CPAP all night from the car's starter battery — that is how people end up needing a jump pack at sunrise. If you want to camp repeatedly from the vehicle, a dedicated auxiliary battery (or a power station charged while driving) is the version that does not strand you.

RV and trailer. With hookups, plug in as you would at home. Boondocking, run the machine off the house battery through an inverter — but check the inverter's idle draw, because a 2,000W inverter can burn more overnight than the CPAP itself. The RV boondocking guide walks through the battery and inverter side if that is your route.

Van and full-time. The pattern that works is a house battery with DC-DC charging from the alternator plus solar, and a dedicated 12V outlet at the head of the bed. It is a bigger project than a power station, and worth it only if you are sleeping in the vehicle more than a few nights a month.

CPAP Camping Checklist

• Machine and its own power brick — for hookup sites you will still want it.
• DC adapter for your exact model, if you are running off a station's 12V output.
• Power station sized to your draw, humidifier off — 300Wh for moderate pressure, 450Wh+ for high pressure.
• Watt meter ($20–30) for the first trip. Run one full night at home on the meter and you will know your real number instead of guessing from a table.
• Foldable solar panel if you are going more than one night.
• Hose cover or a fleece wrap for cold nights, and a spare filter.
• Extension cord (a short 12V one) so the station can sit where it stays warm.
• A dry bag or stuff sack for the machine when it is not in use — tent condensation is real.
• Your prescription or a photo of the settings, in case you need to replace or reconfigure anything on the road.

Camping With a CPAP FAQ

Can I run my CPAP off a portable power station all night?

Yes, at humidifier-off settings on a 300Wh-class station — roughly 7 to 8 hours at 30W, which covers moderate pressure. The catch is the humidifier: with it on, the same station covers about 4 hours. Turn the humidifier off, or size for 500Wh+.

How many nights will a 300Wh station last?

One, at humidifier-off pressures of 8–10. At 40W it is closer to 5.5 hours, so a full second night needs either a recharge or a bigger battery. Add a 100W solar panel and it becomes a renewable one-night-at-a-time setup.

Can I use the humidifier while camping?

You can, if you carry 500–700Wh of battery. Most campers find the trade is not worth the weight: level 1 costs about 15W (under 60Wh a night), which is a reasonable middle ground, while level 3–4 more than doubles the battery you need.

Do I need a special DC adapter?

If your station has a 12V car socket output (most do), yes — a 12V-to-24V DC adapter made for your specific machine, or a 12V cord for machines that take 12V natively. It recovers roughly 10–15% of runtime versus the AC brick. Match the generation: AirSense 10 and AirSense 11 adapters are not interchangeable, and the AirSense 11 has a native DC port while the 10 does not.

What if my campsite has no electricity at all?

That is the normal case for tent camping, and it is exactly what the power station is for. A 300Wh station plus a 100W panel is a self-sustaining one-person CPAP setup for as long as the sun shows up.

Is it safe to use a CPAP in a tent?

Yes. The machine draws a few dozen watts, produces no combustion, and has no flame — it is far safer in a tent than any propane heater. The real risks are mundane: condensation in the hose, a battery that gets too cold, and a cord someone trips over at 2 a.m.

Will cold weather drain the battery faster?

Yes, on both sides. The machine's motor load rises about 10–15% below 50°F, and a lithium battery loses usable capacity in the cold. Add a 15% buffer to your sizing, and keep the station inside the tent rather than in the car.

What about a travel CPAP?

A travel machine (AirMini-class) draws 6–15W, which changes the whole equation: a 292Wh station runs it for two nights with room to spare, and the humidifier question mostly disappears because most travel machines use a passive HME instead of a heated humidifier. If you camp often enough to justify one, it is a bigger upgrade than any battery.

The Bottom Line

Camping with a CPAP is a 300-watt-hour problem, not a generator problem — as long as you turn the humidifier off. Buy a 300Wh LiFePO4 station with pure sine wave output, spend $20–40 on the right DC adapter, measure your actual draw once with a watt meter, and add a 100W folding panel if you want more than one night. That setup fits in a tote bag, weighs under ten pounds, and costs less than a single night in a hotel.

TrailMapz earns a commission on purchases made through links on this page, at no extra cost to you. Power figures are drawn from manufacturer specifications (ResMed AirSense 10: 90W supply; AirSense 11: 65W supply) and published field measurements; your machine's actual draw depends on pressure, humidifier settings and battery age. This is gear advice, not medical advice — talk to your sleep clinician before changing therapy settings.