CPAP Battery Backup Calculator

→ CPAP users who lose power during sleep face immediate health risks — untreated sleep apnea causes oxygen desaturation and cardiac strain.

→ A CPAP with heated humidifier draws 30–60W, while without humidifier it draws only 10–30W — this 2× difference dramatically changes battery requirements.

→ Most CPAP users need 6–10 hours of runtime per night. Undersizing the battery leaves you without power before morning.

→ Camping, travel, and emergency preparedness all require portable CPAP power — but not all power stations handle the load efficiently.

→ Cold weather reduces lithium battery capacity by 10–30%, which can leave CPAP users short during winter outages.

✗ Ignoring the heated humidifier's power impact — it adds 20–40W, effectively doubling or tripling battery consumption versus running without it.

✗ Using AC inverter when 12V DC direct connection is available — inverter losses (10–15%) reduce runtime; most CPAPs have 12V DC adapters.

✗ Assuming the CPAP's power adapter label wattage is the only draw — actual consumption varies with pressure setting and breathing pattern.

✗ Sizing battery for exactly one night without safety margin — cold weather reduces capacity 10–30%, and battery degradation over years reduces usable capacity.

✗ Using a portable power station with low DC output efficiency — some stations lose 20–30% converting battery DC to regulated DC output for CPAP.

✗ Forgetting that higher pressure settings increase power consumption — a CPAP at 15 cmH₂O draws more than one at 8 cmH₂O.

✗ Not accounting for travel altitude and temperature changes — cold camping environments reduce lithium battery capacity significantly.

✗ Assuming all portable power stations handle CPAP loads overnight — a 300Wh station may only last 6–8 hours without humidifier, less with it.