Question for knowledgeable solar experts
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Forum Discussion
My CPAP draws about 1 amp at 12-VDC. I’m not sure how you could draw 5 amps even at 12-VDC, or about 60 watts, unless you were using a humidifier with the heat turned on.
1) Buy a 12-VDC cord and run your CPAP directly off of 12-VDC. You may need to add a 12-VDC outlet, but that is not difficult or expensive. It is wasteful to run the 12-VDC from the battery through an inverter to make 120-VAC, then have the CPAP convert it back to the 12-VDC that it runs on. You have losses at each step in the conversion, plus the inverter has an overhead of probably about 2 amps even when it has nothing drawing power from it. If you don’t need the inverter for something other than the CPAP, turn it off at night.
2) There is enough humidity in the confined quarters of an RV that you should not need heat with the humidifier. Try leaving it off and you will save a lot of power. (Many heated humidifiers will not work on 12-VDC, but you can use them just fine without the heat.)
Wayne
1) Buy a 12-VDC cord and run your CPAP directly off of 12-VDC. You may need to add a 12-VDC outlet, but that is not difficult or expensive. It is wasteful to run the 12-VDC from the battery through an inverter to make 120-VAC, then have the CPAP convert it back to the 12-VDC that it runs on. You have losses at each step in the conversion, plus the inverter has an overhead of probably about 2 amps even when it has nothing drawing power from it. If you don’t need the inverter for something other than the CPAP, turn it off at night.
2) There is enough humidity in the confined quarters of an RV that you should not need heat with the humidifier. Try leaving it off and you will save a lot of power. (Many heated humidifiers will not work on 12-VDC, but you can use them just fine without the heat.)
Wayne
