Propane use with Generator

[Ins. Man]

I have a built in Onan 2500 Propane generator. I must now use a sleep apnea machine and am going camping where there is no electricity. I have 2 30lb tanks and am wondering if anyone could tell me how much propane per hour I might use?

[boo_n_sue]

I too have a CPAP machine and was considering installing a Onan in our 31' Excella II. I'm interested in the propane usage rate as well but equally interested in how you like the Onan? Is it quiet enough for you? Did you install it yourself or did your AS come with already installed?

[Dave Park]

A 12v operable CPAP machine only draws between 2.5 and 4.5 amp-hours. If you sleep for 8 hours, that's 40-72 Amp hours. A pair of AGM batteries can handle this and be charged in the morning.

That's what I would do, because DC is more efficient, without conversion efficiency losses from AC to DC.

[DaveFL]

Most cg require generators to be shut down before 11pm, so to give you the most leeway in where you can camp, batteries are your best option.

[HiHoAgRV]

Originally Posted by Ins. Man

I have a built in Onan 2500 Propane generator. I must now use a sleep apnea machine and am going camping where there is no electricity. I have 2 30lb tanks and am wondering if anyone could tell me how much propane per hour I might use?

Funny, I just had this conversation with my Dad today...his general rule for a slightly larger ONAN was 1lb per hour...it was usually less but not by much. Even at 1/2 of that you are still talkin 'bout a bunch of propane.

[boo_n_sue]

Originally Posted by Dave Park

A 12v operable CPAP machine only draws between 2.5 and 4.5 amp-hours. If you sleep for 8 hours, that's 40-72 Amp hours. A pair of AGM batteries can handle this and be charged in the morning.

That's what I would do, because DC is more efficient, without conversion efficiency losses from AC to DC.

I may not be reading it correctly but I put a Kill A Watt meter on my AC cord for my Respironics REMStar Pro with CFlex and it read .2 to .4 amps when running without the heater and .6 to .75 amps running with the heater/humidifier.

It doesn't have a DC plug so I'll test it running on an inverter off the battery and post those numbers tomorrow.

[Ginder75]

2.5 to 4.5 amps on 12 volts correlates .2 to .4 on 120 volts.