CPAP help, new

Originally posted by TheBum I also have a Respironics System One with dual GC2 batteries, except that mine are 230Ah. The AC power supply is rated at 65W, so I figure I could run my CPAP for 21 hours (115Ah * 12V = 1380WA / 65W) with the humidifier on if that's the only load on the batteries, so the batteries will easily handle a single night of the CPAP with humidifier and all other loads.

Using two of those batteries (230 ah @ 6V), each battery has a total of 1380 WH, for a total of 2760 WH to full depletion. Assuming they are wet batteries, they can safely be depleted to ~~ 50%, for a total of 1380 WH. If they are AGM batteries, they could be depleted (typically) to ~~ 75% depletion, so that would give you ~~ 2070 WH.

It's funny. We went out on a hike yesterday, and because we were traveling to an area where we don't often go, we turned on the local news/weather/traffic station while going there. Coincidentally, they were advertising a Transcend mini-CPAP, and promoting the low power/DC operation.

What I did was purchase the two 6V batteries plus the cable needed to connect them together and took them with me when I went to pick up our 179. Because I did not take the 12V battery, the dealer did give me a credit which I used in the store to purchase some of the accessories we needed.

Originally posted by NAP1947 As you all realize I am no electric expert and typing skills are not great either. Thank you for the advice, I did not realize that we could turn off the CPAP heaters, in fact we do not even need to use the tank and being that I have read humidity can be a problem in the Pod perhaps that might meet our needs. I will go with the single 12 volt or get the dealer to not provide a battery at all and then get golf cart batteries and case in the US. Assuming your calculations are better than mine, I believe it is worth going the battery route, that is my first choice and if we find the need we could consider a generator at a later date. Cheers

Here is a bit of rub.. you can't "tow without a battery installed. It's what powers the emergency breakaway for the braking system. ANY 12v battery that works, will do. But you have to have one installed and functional, to tow.

+1 on the dual GC2 batteries. I use a CPAP machine. I installed 12V outlets so I could run it directly (Respironics System One). I use the humidifier at home but when I am in the R-Pod, I put water in the tank but set it to "0" to save power. That way, I have passive humidification from the air passing over the water but I save power. I have gone multiple nights with the CPAP with the furnace also running.

I think the power draw mentioned above is the maximum use. Mine has 12V 6.67A on the label and to use with either a 60W or 80W power supply. The 80W is for use with a heated hose, which I don't have. Doing the math on the label figures, the maximum power draw is 80.04 Watts. Most of that power is used to heat the water in the humidifier. Turn the humidifier off, and the power draw is much less, but there is no label to tell how much of that power draw is for the humidifier and how much for the main unit. The best I can find out by searching is that without the humidifier, the CPAP unit will draw approximately 1.8A, depending on pressure. It will draw less when you exhale. Let's say 2A per unit. That would be 4A/hour to run the two CPAP machines without the humidifiers. If you go with the GC2 batteries, you should not have any problems powering them at night. Then you could use a generator during daytime hours to charge the batteries.

If you look at my mods, you will see my batteries. I got the 215 AH Duracell batteries at Batteries plus Bulbs. You can get a discount if you order online and pick up in your nearest store. They do have a military discount.