CPAP machine

cpu266 wrote:
some cpap manufactures have a 12v adapter one can get. hooks to 12v source and powers machine. some even shut unit off if voltage of battery drops to low.

what make/model cpap does he have?
bumpy

We use a cpap and Dw a Bipap, powering them from inside a rv is not difficult.
If the unit has a brick (large plastic box transformer) in the cord check the voltages on that. It likely is a 12 volt unit. If so, you can get 12 volt power cords to allow you to connect it to the trailers 12 battery power. My Respironics CPAP is listed as drawing a maximum of 5 amps at 12 volts, since I dont use the humidifier, it actually draws less than half that.
12 volt cords are available from most manufacturers for their models, you just need your model # .
If your unit will require 120VAC an inverter will be required to convert the 12 volt DC from the battery to 120 VAC, a pure sine wave inverter would be the safest for protecting the machine and will need to be more than 300 watt continious in size, preferably 500 watts.
Either way you will need a good battery/batteries on the RV with at least 40 amp/hrs available to maintain power for the unit, and a suitable method of recharging during the day.

some cpap manufactures have a 12v adapter one can get. hooks to 12v source and powers machine. some even shut unit off if voltage of battery drops to low.

Well, there are battery powered Cpap machines that might work for you.
What you need probably is an INverter. That takes 12VDC and converts it to 120VAC. Depending on the amp draw of his machine a 1000 watt unit will probably work just fine. INverters need to be placed as close to the battery bask as possible. Then its a matter of adding an inline fuse between the batteries and INverter and using sufficiently large gage wire to carry the load. From the INverter you can simply run a dedicated line to new receptacle near the bed.

Are you looking to run the CPAP machine off of batteries versus plugged into power?