DIY POWER SOURCE

[Caedus]

So is a deep cycle marine battery and an inverter all I need to power my Phillips repironics in a power outage?

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[Guest]

So is a deep cycle marine battery and an inverter all I need to power my Phillips repironics in a power outage?

Sent from my SAMSUNG-SM-G935A using Tapatalk

If you have a Respironics cpap you will do better if you buy (or make) the DC adapter for your cpap then connect directly to the battery. Plenty of discussions about using battery power for camping or during a power outage on this forum if you do a search.

[CapnLoki]

So is a deep cycle marine battery and an inverter all I need to power my Phillips repironics in a power outage?

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It works just fine. However, inverters tend to be about 60% efficient, so you get almost twice the power using the direct 12Volt power cord, cost about $25. Also, the humidifier/heated hose uses 3-6 time more power than the pump itself, so a battery that can carry a pump for a week may not last 2 nights with full humidity.

For a study in usage:
viewtopic.php?t=102179

For a description of a backup system:
viewtopic.php?t=102775

[ClayL]

My Xantrex Prowatt 600 pure sine wave inverter claims to be 90% efficient.
Access to the 12 dc line in my motor home was a problem since the bedroom was in one of the slides. It was much simpler for me to mount the inverter next to the house batteries and use a transfer switch to connect it to the 120 house wiring.

[CapnLoki]

My Xantrex Prowatt 600 pure sine wave inverter claims to be 90% efficient.
Access to the 12 dc line in my motor home was a problem since the bedroom was in one of the slides. It was much simpler for me to mount the inverter next to the house batteries and use a transfer switch to connect it to the 120 house wiring.

Yes, they invariably claim 90%, but if you can find the real specs, or measure them, you usually find that the 90% only holds true near the peak rating. In your case, assuming a humidifier, you're running at about 8% of peak rating, maybe less.

BTW, I have two Xantrex inverters, a small one that I measured 57% efficiency with a cpap, and a large (2000 Watt) that is very efficient when powering a microwave, but I'm sure is well under 50%, maybe 10%, with a small load. I live on battery power for several months in the summer, and I've learned to have a variety of inverters for different power loads, and I try to run as much as possible (cpap, refrigerator, computers, etc) directly from 12V. The goal is only use power I get from solar - in three months this summer I only ran the engine briefly a couple of time to make hot water.