CPAP Machine Runtime on 50Ah Battery
A 50Ah battery is the minimum viable option for CPAP backup. It provides 1-2 nights of power without the humidifier, making it suitable for emergency backup or short camping trips. The compact size (15-20 lbs for LiFePO4) makes it highly portable.
Disclaimer: This calculator provides electrical power estimates only and is not medical advice. Always consult your healthcare provider and device manufacturer for medical device power requirements. Have backup plans for life-critical equipment.
Typical Runtime
13hrs
Efficient/Low Power
20hrs
Worst Case
6.5hrs
Battery Energy
480Wh usable
- ✓Emergency backup for power outages (1-2 nights)
- ✓Weekend camping trips
- ✓Travel when you have daily charging access
- ✓Testing if battery backup works for you before investing more
- !Only 1-2 nights without recharging
- !Must disable humidifier to get reasonable runtime
- !No buffer for cloudy days if relying on solar
- !Not suitable for extended off-grid use
- ↑You need humidifier function (cuts runtime in half)
- ↑You want 3+ nights of backup
- ↑You camp frequently without shore power
- ↑You live in an area with frequent multi-day outages
- ↓This is the minimum recommended size for CPAP
Minimum Solar
50W
Ideal Solar
100W
Recharge Time
~6 hrs
A 100W panel provides comfortable daily recharging even on partly cloudy days.
Tips for CPAP Machine on 50Ah
- •Disable heated humidifier to nearly double runtime
- •Use a DC-to-DC adapter instead of inverter to gain 15-20% efficiency
- •Keep battery above 50°F for optimal performance
- •A 100W solar panel can fully recharge this battery in 6-8 hours
- •Consider a travel CPAP (20W) like ResMed AirMini for maximum runtime
Frequently Asked Questions
Will a 50Ah battery run my CPAP all night?
Yes, if you disable the humidifier. At 30W, a 50Ah LiFePO4 battery provides about 13 hours of runtime - enough for 1-2 nights. With the humidifier enabled (60W), expect only 6-7 hours.
Is 50Ah enough for camping with CPAP?
For a weekend trip with daily solar charging, yes. For longer trips without reliable charging, upgrade to 100Ah for peace of mind.
What inverter size for CPAP with 50Ah battery?
A 150-300W pure sine wave inverter is sufficient. However, using a DC-to-DC adapter (if your CPAP supports 12V input) is more efficient and recommended.