If accurate then that decal is saying the device draws 5 amp hours per hour. So if you are running the machine for 8 hours you would be pulling 40ah. That is pretty high. Therefore you would want a big battery to keep the battery happy and long lasting. Something in the 90-100ah range. You will see this repeated over and over again by me in other threads. AGM batteries as in anything other than lithium-ion do not like to be drained down below 50%. It kills the lifespan of the batteries.
Here's a lengthy discussion on EP:
http://forum.expeditionportal.com/threads/172079-CPAP-Power-Questions
Wiring up something like this between your CPAP machine or fridge will give you much more accurate power consumption readings.
T-Trees FT08 RC 150A Watt Meter Power Analyzer With Backlight LCD Hight Precision
by T-Trees
Link:
http://a.co/bOIokeo
A fridge, for example, may have a 2.5AH draw. That of course is only when it is running. So depending on ambient temp and fridge temperature setting the amp draw will vary greatly. For the CPAP I would assume the power consumption would be a lot more predictable.
