Originally Posted by JD57
Hi. Just purchased our first RV yesterday and will pick up in couple of weeks. 2015 3050S. Dealer advised it has 1000w inverter, and solar. Plugs will only work when docked or on generator, otherwise 12v plugins throughout unit. I have a CPAP machine, so do I have to purchase a DC adapter for it? I thought inverter allowed me to "plug" in AC items into trailer plugs, limiting my draw to unit demands. Is this a common thing for Sunseeker or all Class C's? Should I be considering upgrading/modifying with larger inverter? Appreciate all assistance, and looking forward to future adventures!
There are a few things you must understand about your CPAP machine and your settings before you size batteries, reserve power and solar panels.
1. If you have an adapter for 12V direct current for your CPAP machine you will save energy lost in the conversion via the inverter. If you get an inverter, you should get a pure sine wave inverter (expensive). Some CPAP machines will allow modified sine wave inverter (cheaper). There is also a square sine wave inverter. Use recommended type of inverter from CPAP manufacturer. If you do not use the recommended type inverter you will most likely damage your CPAP machine.
2. Your CPAP machine uses current based on your pressure settings, so to size how much battery power you need, you will need to get those numbers together.
3. If you use a humidifier on your CPAP machine, then your power consumption most likely will triple. If you are using ResMed CPAP, you are in luck, in that their site published DC power requirements for pressures and humidification, and has diagram. ResMed S9 DC Converter is around $80.
In summary, before you buy an inverter, converter, battery or solar panels for your CPAP machine, understands your requirements.
One last thought, if you are buying a separate battery as reserve power for your CPAP machine, then you could also use it as backup at home if you have a power failure. Size it based on amperage CPAP uses and available battery reserve capacity needed. Plan not to discharge your battery down to 50% when in use.