gregoryabell@bellsouth.net Report post Posted April 15, 2021 I will be renting a RV in Alaska that does not have an inverter. I need to purchase an inverter that can run inside the unit connecting to the cigarette lighter to power my CPAP machine. I want to be able to use the CPAP machine with the humidifier and heat tube features engaged. Is there an inverter made with a cigarette lighter connection that has sufficient continuous wattage power to run my CPAP machine with these features engaged, and if so, who is the manufacturer and what is the model? Share this post Link to post Share on other sites
hermanmullins Report post Posted April 15, 2021 Gregory, Welcome to the Forum. A problem that you may have is the Battery in the rental RV. To run all you have described you may need to purchase a charger for the battery to keep the power reserve up the be able to run what you described. It shouldn't be an issue when hooked to shore power. But dry camping will be another issue where you don't have a place to plug in the charger. Are you sure the unit you will be renting doesn't have an inverter? Herman Share this post Link to post Share on other sites
rayin Report post Posted April 15, 2021 Locate the nameplate/dataplate on your CPAP machine, write down the total wattage draw for each function, add them together. This is the absolute minimum inverter size you require, not including starting draw of anything with an electric motor. Now you must know the battery size, total amps available and how many batteries are in the rental before you can calculate how long you can use your CPAP machine before the house battery bank is dead. Welcome to the FMCA discussion forums, please return often! Share this post Link to post Share on other sites
bm02tj Report post Posted April 15, 2021 You need to test before you go as you may need a pure sine unit as modified sine does not work for a lot of stuff Share this post Link to post Share on other sites
rossboyer Report post Posted April 15, 2021 I have had two different manufacturers of CPAP machines. I bought for one a cord to operate directly from a 12 volt lighter type outlet. The other was a power brick that doubled the 12 volt to 24 volt, because that machine was 24 volt. You will have greater efficiency powering with one of these solutions vs inverter from 12 volt to 120 volt and then back down to 12 or 24 volts as needed. Be aware that many auto manufacturers are not powering what use to be lighter outlets with high amperage, because so many users are now only using the outlet to power USB converters or low power electronics. Share this post Link to post Share on other sites
manholt Report post Posted April 16, 2021 If your rental does not have a inverter/charger, find a rental firm that does! You can rent a RV, mostly class C or B anywhere in the world and I have never heard of one that can't boondock! Share this post Link to post Share on other sites
C-931549 Report post Posted April 19, 2021 On 4/15/2021 at 10:08 AM, bm02tj said: You need to test before you go as you may need a pure sine unit as modified sine does not work for a lot of stuff I second this. Check with your CPAP manufacturer. You don't want to fry your machine. I tried using a modified sine inverter to charge my CPAP's battery backup. Maybe it's just coincidence, but the battery failed after the second time I charged it this way. Share this post Link to post Share on other sites
kaypsmith Report post Posted April 20, 2021 On 4/15/2021 at 12:47 PM, rossboyer said: I bought for one a cord to operate directly from a 12 volt lighter type outlet. The other was a power brick that doubled the 12 volt to 24 volt, because that machine was 24 volt. You will have greater efficiency powering with one of these solutions vs inverter from 12 volt to 120 volt and then back down to 12 or 24 volts as needed. I second this post. Share this post Link to post Share on other sites
