OUPES uses LiFePO4 battery, LiFePO4 battery is eco-friendly and more stable, the safest battery on the market with no heavy metal elements that are harmful to people.

Most CPAP machines are between 30-60 Watts. Watts is a unit of power and a function of current (amps) and volts (Watts= amps x volts).
OUPES 600W and 1100J are enough to power a CPAP machine. the working hours = Watt-hours *0.85 / watts.

Please kindly store the power station within 0-40℃. And please recharge it every 6-month to keep the battery power above 50% if you don't use it. Are all OUPES Portable Power Stations come with pure-sine wave inverter? Yes, all Oupes portable power stations use Pure-sine wave inverters.

Yes, all Oupes portable power stations use Pure-sine wave inverters.

First, you need to check out your device's operating power (measured by watts), if it is no more than the output power of the portable power station's AC port, it can be supported by the power station.
Then, you can calculate the charging time by the formula: Working time = power station's Watt-Hous * 0.85 / operating power of your device.
For reference, assuming power consumption of your device is 60W (might be a box fan), and you want to use the OUPES 600W to run your device. The working time will be 595wh*0.85/60w=8.5 hrs (rough calculated). Please note the actual power consumption varies from different usages, consult OUPES for a better purchase decision.

Unfortunately, you can't. Under FAA regulations you are not allowed to take any battery exceeding 100Wh on a plane.

Modified sine wave inverters are very affordable. Using a more basic form of technology than pure sine wave inverters, they produce power that is perfectly adequate for powering simple electronics, like your laptop. Modified inverters are best suited for resistive loads which don't have a start up surge.

Pure sine wave inverters use more sophisticated technology to protect even the most sensitive electronics. Pure sine wave inverters produce power which equals – or is better than – the power in your home. Appliances that may not function properly, or which may be permanently damaged, without pure, smooth power will be safe with pure sine inverters.