
CPAP energy stations: autonomy & 12V/AC
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CPAP Power Stations: 300-700 Wh , 12 V direct vs AC 230 V pure sine wave , full night 's runtime, humidifier & UPS - the 2025 guide
Need to power a CPAP (sleep apnea) while traveling , in a van or during a power outage ? This guide simply explains how to choose a suitable power station : capacity (Wh) to last the night, power (W), direct 12V DC output (higher efficiency) or pure sine wave AC 230V , impact of the humidifier & heated hose , real autonomy calculations, USB-C/mains/MPPT solar charging, UPS mode to automatically switch over in the event of a micro-outage, and the LymobileShop selection ready for purchase.
1) Understand the needs of a CPAP (W & modes)
A CPAP generally consumes between 25 and 60 W in basic operation. With a humidifier and/or heated hose , consumption can rise to 60–100 W (or more depending on temperature & settings).
- Without humidif./heating pipe : 25–45 W typical.
- With humidification : +15–30 W depending on heating level.
- With heated pipe : +10–20 W on average.
- “Eco” mode on certain machines: reduces heating and consumption.
Tip: If you sleep warm , lowering the heat on the humidifier and hose will drastically increase battery life.
2) Wh (autonomy) & W (power): the formula that works
The capacity of a station is measured in Wh (Watt-hours). The inverter power (W) indicates what it can supply instantly.
Formula for estimating autonomy:
Autonomie ≈ Capacité(Wh) × Rendement / Charge(W)
- AC 230 V connection (station mains socket): assumes an efficiency of ~0.80–0.85 (inverter losses + heat).
- 12V DC connection (cigarette lighter output/regulated DC socket): takes ~0.90–0.95 (best efficiency).
Examples (512 Wh station):
- CPAP 35 W at 12 V : 512 × 0.92 / 35 ≈ ~13.5 h .
- CPAP 35 W in AC : 512 × 0.85 / 35 ≈ ~12.4 h .
- CPAP 70 W (humidif.+hose) in AC : 512 × 0.85 / 70 ≈ ~6.2 h .
3) 12 V direct vs AC 230 V : which connection should you choose?
-
12 V DC direct (recommended when possible):
- Higher yield → more hours for the same station.
- Less heat, less noise (fans).
- Often requires an official 12V cable from the CPAP manufacturer (polarity & regulation).
-
AC 230 V (pure sine):
- Compatible with the mains power supply supplied with the CPAP.
- Essential if you don't have a 12V adapter for your model.
- Slightly lower autonomy than with 12 V direct (inverter losses).
Conclusion: If your CPAP accepts a certified 12V cable , this is the best choice. Otherwise, use the 230V pure sine wave AC outlet of a suitable station.
4) Humidifier & heated hose: massive impact on autonomy
These two elements are the “big consumers”. Some pointers:
- Humidifier = +15–30 W depending on the level. In dry weather, use a larger station.
- Heating pipe = +10–20 W. The cooler the room, the more it consumes.
- Tips : Reduce the heat by 1–2 notches, use an insulating cover on the pipe, avoid direct drafts.
Example: CPAP 35 W → + medium humidification (+20 W) → + hose (+12 W) ≈ ~67 W. The same station will last almost half as long as in “dry” mode.
5) Which capacity to choose: 300/500/700 Wh
300 Wh (compact)
- Without humidification. ~25–40 W: 300 × 0.92 / 35 ≈ ~7.9 h (at 12 V).
- With humidif. ~60–70 W: 300 × 0.85 / 65 ≈ ~3.9 h (in AC).
- For whom : “short” night, emergency assistance , summer trip/hotel/van (heat = less heating).
500–512 Wh (balance)
- Without humidity. 35 W: 512 × 0.92 / 35 ≈ ~13.5 h (12 V).
- With humidif. 60–70 W: 512 × 0.85 / 65 ≈ ~6.7 h (AC).
- For whom : a peaceful night's sleep , room for variation, better weight/battery life ratio.
700 Wh (advanced all-rounder)
- Without humidity. 35 W: 700 × 0.92 / 35 ≈ ~18.4 h (12 V).
- With humidifier 70 W: 700 × 0.85 / 70 ≈ ~8.5 h (AC).
- For whom : winter , altitude, heated pipe, van + margin for recharging smartphone/tablet.
6) Charging: fast mains, 12V car, MPPT solar
- Mains : 200–600 W input depending on model (512 Wh at 300 W ≈ ~2 h ).
- 12V car : practical on the road (60–120W), slower but free during the journey.
-
MPPT solar : typical torque
- 300 Wh → 100–120 W foldable = ~3–5 h strong sun.
- 512 Wh → 120–160 W = ~4–6 h.
- 700 Wh → 160–200 W = ~4–7 h.
- Pass-through : You can charge the station during the day (solar/car) while using it at night. Avoid unnecessary 24/7 loops.
7) UPS mode: anti-power cut-off safety for the night
A UPS -compatible station switches from mains to battery power in the event of a power outage (short transfer time), without turning off the CPAP. It's the "zero stress" solution for your home.
- Usage : Plug the station into the mains, and the CPAP into the station. Normally, the CPAP is powered by the mains via the station. In the event of a power outage, the station takes over.
- Tips : Check UPS compatibility & advertised transfer time; do a 5 minute test during the day, before night.
8) Noise, heat, placement & safety
- Fans : Activate if the station is charging/charging heavily or becomes hot. Place it on a hard, well-ventilated surface .
- Temperature : avoid radiators and direct sunlight; the electronics limit power in hot weather (perceived reduced autonomy).
- 12 V : locks the plug well (some tips have a twist-lock ).
- Safety : favors LiFePO4 stations (longevity, stability), complete BMS (OVP/OCP/OTP/UVP), pure sine wave in AC.
9) Ready scenarios
Home & Micro-cuts (UPS)
- Station : 500–700 Wh, UPS , pure sine AC, 12 V stable.
- Connection : CPAP on 12 V if official cable; otherwise AC.
- Typical autonomy : 512 Wh, CPAP 35 W 12 V → ~13.5 h .
Van / winter camping
- Station : 700 Wh, LiFePO4, 12 V 10–15 A, MPPT.
- Solar : 160–200W foldable. Charge during the day, sleep soundly.
- Settings : humidif. + hose ≈ 60–80 W → ~8–9 h (AC) on 700 Wh.
Hotel / business trip
- Station : 300–500 Wh compact.
- Connection : often AC (original CPAP mains socket); brings short multi-socket & 12V cable if compatible.
- Tip : Lower the humidity if the air is not too dry.
Illuminated bivouac
- Station : 500 Wh + 120–160 W panel .
- Plus : LED lamps (5–10 W), smartphone/tablet charging via USB-C.
- Objective : to complete the day/night cycle without a sector.
10) Sizing tables (order of magnitude)
10.1 Estimated autonomy according to configuration
Station | Connection | CPAP consumption | Autonomy ≈ |
---|---|---|---|
300 Wh | 12 V DC | 35 W | ~7.5–8.5 h |
300 Wh | AC | 65–70 W | ~3.5–4 h |
512 Wh | 12 V DC | 35 W | ~12.5–14 h |
512 Wh | AC | 65–70 W | ~6–7 h |
700 Wh | 12 V DC | 35 W | ~5–7 p.m. |
700 Wh | AC | 65–70 W | ~8–9 h |
10.2 Recommended folding panels (daytime charging)
Station capacity | Sign | Charging time (strong sun) |
---|---|---|
~300 Wh | 100–120 W | ~3–5 h |
~512 Wh | 120–160 W | ~4–6 h |
~700 Wh | 160–200 W | ~4–7 h |
Notes : Indicative values (effective MPPT, optimal angle, short cables, mild weather). In winter/clouds, allow more.
11) Express shopping checklist
- Capacity : 300 Wh (emergency), 500 Wh (full night), 700 Wh (winter/margin).
- Connection : prefer 12 V DC with official CPAP cable; otherwise AC 230 V pure sine .
- Power : ≥300–500 W inverter for comfort (AC).
- Chemistry : LiFePO4 (longevity, thermal stability) recommended.
- UPS : if used at home → automatic switchover in the event of a power outage.
- MPPT solar : 100–200 W depending on capacity for daytime charging.
- Noise & placement : hard, ventilated surface; avoid fabrics & heat.
- Accessories : 100W USB-C cables (smartphones/tablets), 12V CPAP certified cable.
12) LymobileShop Selection (CPAP-Ready)
Stations ~300 Wh — compact
- For : repairs, hotels, light nights without humidification.
- Advantages : Pure sine AC 300–500 W, stable 12 V, USB-C.
Stations ~500–512 Wh — full night balance
- For : peaceful night, home UPS, mid-season van.
- Advantages : LiFePO4, AC 500–700 W, 12 V 10–15 A, MPPT .
Stations ~700 Wh — winter & comfort margin
- For : humidif. + hose, altitude, cold van.
- Advantages : 700–1000 W inverter, high peak, multi-port.
100–200 W foldable panels
- For : day/night autonomy in van/home base.
- Pros : MC4/DC, kickstands, 70–170W usable output.
13) CPAP & Energy Stations FAQ
12V or AC: Which lasts longer?
Direct 12V lasts longer (less loss). Use your CPAP's official 12V cable if available.
What capacity for a full night with humidifier?
500–700 Wh depending on settings. At 65–70 W AC, aim for 700 Wh for margin.
LiFePO4 mandatory?
Recommended: better longevity (cycles) & thermal stability. Li-ion OK for occasional use/tight budget.
Is UPS mode useful?
Yes, for home use : automatic switchover in the event of a micro-outage, without interrupting the CPAP.
Can I charge while driving?
Yes via 12V car (60–120W) and supplement with a folding panel at the camp.
And the plane?
Stations often exceed 100 Wh → check with the airline (limited tolerance & agreement). For air travel, take a power bank ≤100 Wh in the cabin (not for all-night CPAP).
14) Trust & Services LymobileShop
- Delivery : free in France, fast shipping.
- Payment : secure, several methods to choose from.
- After-sales service : team in France, assistance with CPAP sizing (W/Wh, 12 V/AC, UPS, solar).
- Returns & Warranty : 14 days to change your mind, 2 year warranty .