Need inverter info

First thing needed is an adequately sized battery bank. How much will the CPAP, phone chargers & anything else need? From that number you get an idea of the size of inverter needed. Make sure the inverter is not being maxed out. It won't last long that way. Finally determine if you need a pure sine wave or modified sine wave inverter. Learn the difference between the two. What seems like a saving upfront may cost you many dollars more in the long run by going cheap.

I recently had to get a cpap. First concern was, what about camping? My wife said , you can make it work, whatever it takes. I did some research and found out that yes you can use your house or 12v battery but the recharge time is quite a bit. We camp with out power and generator use is limited to 2 hours in the morning and 2hrs at night. Not enough time to recharge the house battery. Next option I looked at was the portable battery offered by the place where I bought my cpap. It allows 13 hrs use without humidifier and heated hose. Best thing is that the recharge time is 2_4 hours. It is very compact, smaller than the cpap itself. Was 450.00 cdn. I have since done a test run at home. 8 hrs sleep, turned off humidifier and heated hose, recharged in 2 hours. I always use those but for camping to save power consumption I will not. It was fine as it was. It's a good chunk of change but well worth it.

I agree with GordonThree,

Victron makes a 350 watt PSW inverter and it retails for under $100.00.

I happen to own one. It weighs 7.5 lbs.

You need one of two bits of info
SOME CPAP's can run on battery power (12 volts) you can even get a car cord for 'em. (Suggestion)>

Option 2: you need to know the maximum power for CPAP and himidifer (if you have one) and then multiply that by at least 1.5. I suspect a 300 watt PURE SINE WAVE inverter (Several on the market most are good) will do the trick.

Victron Energy also makes a very reasonably priced high quality small inverter.

I have and recommend GoPower sine wave inverters. Probably 300 watts will do and makes for an easy install. Check power requirements. Don't forget some extra battery.

A CPAP doesnt mean you have to have an inverter.
Many actually run on 12 volt DC the same as your battery system in most RV's. If your unit has a plastic block (Like a brick) in the power cord there is a good chance its a converter to give the machine 12 volt dc power.
Check your unit, verify brand and model number and then go to either the manufacturer or to an aftermarket seller to look for DC power cords.
Here is one site that sells these products, there are many others.
CPAP

The round cigarette lighter style plugs are usually found somewhere near the bed, so hopefully you wont have to install one.
My unit without the humidifier uses about 4 amps when running, m'ladies with humidifier uses about 7.5, so you may want to increase the size of your house battery.

Start with determining how much power your CPAP uses each night then match your battery reserve to be able to provide the necessary power. From there you can then determine the size of inverter you need.