Oxygen Concentrator Runtime on 400Ah Battery
A 400Ah battery provides 9+ hours for a home oxygen concentrator - true overnight capability. This is the recommended size for those who need reliable overnight backup without running a generator while sleeping.
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
9hrs
Efficient/Low Power
32hrs
Worst Case
5.3hrs
Battery Energy
3840Wh usable
- ✓Overnight backup without generator noise
- ✓Extended power outages (8-12 hours)
- ✓Remote locations with unreliable power
- ✓Maximum peace of mind for oxygen-dependent users
- !Significant cost and weight
- !Should be 24V or 48V system at this capacity
- !Still need generator for multi-day outages
- !Large inverter required (1000W+)
- ↑You need to power additional medical equipment
- ↑You are building a whole-home backup system
- ↑Outages in your area commonly exceed 12 hours
- ↓You have reliable generator backup for overnight
- ↓Budget constraints make 300Ah more practical
Minimum Solar
800W
Ideal Solar
1000W
Recharge Time
~5 hrs
1000W solar can nearly keep up with daily oxygen concentrator use, reducing generator dependency significantly.
Tips for Oxygen Concentrator on 400Ah
- •400Ah at 24V or 48V is far more practical than 12V at this capacity
- •This provides true overnight backup for home oxygen concentrators
- •Combine with auto-start generator for unlimited unattended runtime
- •Consider medical-grade UPS for instant switchover
- •Keep backup portable concentrator for generator failure scenarios
Frequently Asked Questions
Is 400Ah enough for overnight oxygen concentrator?
Yes, for most home concentrators. A 5L unit (350W) gets 9+ hours - enough for a full night. You can sleep without running a noisy generator.
What voltage system for 400Ah oxygen backup?
Strongly recommend 24V or 48V. At 12V, a 350W load draws 29+ amps continuously - requiring very heavy cables and causing efficiency losses. 24V or 48V is much more practical.
Can I run oxygen concentrator and CPAP on 400Ah?
Yes. Together they draw about 380-400W. You get approximately 8 hours of runtime - enough for overnight. Add 800W+ solar to recharge for the next night.