Contributor III
I haven't been camping since I've started using a c pap machine. Any suggestion on how to power it if not at a campsite with electric hookups.?
Contributor III
Pathfinder II
1358
Off-Road Ranger I
1519
The pic above your post shows 5A at 12V. So at 60W, that falls in the range you posted. I assume its a continuous load (?). If so, assuming the user hits the rack at 9PM and is awake by 6AM (at least off the CPAP machine) then thats 9 hours of use at 5A. 9H x 5A = 45AH (Amp Hours) at 12V. Some loss will occur via the inverter. 15% loss is pretty common in smaller, usually less efficient, inverters so thats gives us 45AH x 1.15 = 51.75AH.Looks like for the standard c pap your typical consumption is 53w with peak at 104w.
I have a 1000w inverter installed in my truck which would be far more than you'd need to run a c pap. You could do with a 250 watt inverter (pure sine wave inverter is what I recommend).
I didn't do the calculation to determine what kind of battery or battery bank you'd need because I don't recall the formula off the top of my head, but I would have an additional battery to run the c pap from rather than your cranking battery
Ha, just looked at the image again. It shows the device is DC, so scratch inverter loss if you CPAP can be directly 12V driven.The pic above your post shows 5A at 12V. So at 60W, that falls in the range you posted. I assume its a continuous load (?). If so, assuming the user hits the rack at 9PM and is awake by 6AM (at least off the CPAP machine) then thats 9 hours of use at 5A. 9H x 5A = 45AH (Amp Hours) at 12V. Some loss will occur via the inverter. 15% loss is pretty common in smaller, usually less efficient, inverters so thats gives us 45AH x 1.15 = 51.75AH.
So, a fully charged 100AH battery should be about 50% discharged by 6AM...or still at about 12V. You dont want to go much lower than that because its bad for the battery. This should be a deep cycle battery so it can handle repeated deep discharges, not a starting battery. (Note: there are a number of different methods used to calculate a battery AH ratings. Which method is used may change the logic above).
If the machine uses a power supply ("wall wart") then those are often very inneficient and could add significantly to total AH's used.
A CPAP driven directly by 12V would be more efficient.
Contributor III
Steward I
8750
I'm pretty sure I saw a portable battery operated cpap advertised on tv.I haven't been camping since I've started using a c pap machine. Any suggestion on how to power it if not at a campsite with electric hookups.?
http://www.thecpapshop.com/our-cpap-machines/travel-cpap-machines. This is one of many sites. Transcend is a big player with great quality. No need for AC conversion.I'm pretty sure I saw a portable battery operated cpap advertised on tv.
Member III
8300
Just a standard battery? I was worried that I would drain the vehicle battery, so I bought a deep cycle and built something similar to this. While heavy, it's portable, so I can use it in a tent as well, and not be limited to sleeping in the truck.With just the truck battery I could go two night running my machine and not driving the truck. However the battery was weak on the second morning start up.
Member III
8300
I used about a 30 foot extension for the 12v cord.Just a standard battery? I was worried that I would drain the vehicle battery, so I bought a deep cycle and built something similar to this. While heavy, it's portable, so I can use it in a tent as well, and not be limited to sleeping in the truck.
Off-Road Ranger I
8730
On behalf of everyone in the campsite of those of you bringing your cpaps, let me say, Thank you. My dad never took me camping but if I got stuck in a car, hotel room, pretty much anywhere he was sleeping, I would go insane. He was so loud that once, when another kid was spending the night at my house, he woke my brother up to tell him someone was running a motorcycle through our yard.Camping all these years people would talk about the Bear they heard through the night. About 2011 I got my resmed 9s with humidifier. Ran it with my Honda 2000 generator for years until I found the 12v plug. With just the truck battery I could go two night running my machine and not driving the truck. However the battery was weak on the second morning start up. If you are driving the truck each day; you should be fine. I just got the resmed 10s and ordered the 12v plug. Looking forward to testing it out.
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