Thursday, Mar 13, 2014 at 20:06
Well folks, I haven't been ignoring you. I have been very busy conducting tests using a friend's set of 150W panels and the math is in! It seems that the 75W figure as quoted in the CPAP manual for flight mode is, shall we say, not as accurate as it could be.
OK here goes.... Fisher and Paykel Nova machine set to "flight mode" (all humidifier and hose heating off)
150W inverter.
150W solar panels.
120 Ah battery
I measured the DC load going into the inverter with nothing plugged into the inverter but the switch ON. = 360mA @ 11.78 Vdc
Next
test, inverter plus CPAP machine on in flight mode, CPAP pressure at 4cmH2O =1.5AmpsDC @11.7Vdc.
So, if my math is correct, this should give me a power consumption figure of 17.55W
A far cry from the 75W quoted in the manual.
So, I'm back to 30 Ah for my Waeco CF50, 11.7Ah for 8 hrs CPAP running plus 6Ah or so for
camp lights etc. A tick under 50Ah.
Given an ideal solar gathering day and a healthy 120Ah battery, I reckon I should be able to get away with the 150W panel set?
Thoughts?
FollowupID:
810764