Our units have been tested for up to 8,000 feet. We cannot guarantee the operation of the device above 8,000 feet.
No, we currently do not sell solar chargers. Additionally, we are not aware of a solar charger that works with our device.
Yes, the Z1 and Z2 CPAPs are FAA compliant for use on airplanes. The FAA compliance letter is in the back of the User Guide. Detach it from the Guide and bring it with you on your flight.
The Z1 and Z2 run on electricity from 100-240V which means you will not need a converter for international travel. You will only need a plug adapter to fit the right configuration for the country you are visiting.
The minimum voltage you will need to charge your PowerShell is 12 volts.
The PowerShell auxiliary plug is designed to work with 12v systems. If the system drops below 12v the system may shut off.