inverter question

[dog_soldier]

my wife has to use a cpap at nite to sleep. i got thinking that instead of running the genset just for that why not get a inverter.
so my question is what watt would i need to get?
i found a 400 watt and was wondering if it would work?
here is the link to the 400 watt
Cobra Power Inverter 400 watt - DonRowe.com or would i need something bigger?

[TandW]

Determine the wattage drawn by the cpap unit. Then multiply by 1.8. Purchase an inverter that is rated at least for that figure. Then you will have an inverter that will run reliably for the long term. I run thru the night with my oxygen concentrator on inverter and batteries when boondocking. You may need more batteries. I have eleven 12 volt batteries. Good luck!!

[GaryKD]

Hi dog_soldier,
My wifes machine runs at about 50 WATTS. 12 VDC X 4.16 AMPS = 49.92 WATTS. Look at the machine and determine the WATTs needed (Volts X AMPS) = WATTS. Then you will know how large an inverter to purchase. Make sure your batteries are up for the workout.