Minimum DC Voltage to Operate CPAP?

[daddyoh]

No Worries JJJ I hope it works out for you  .

[JJJ]

JJJ:
I picked up the inverter this morning, and tonight we'll see what happens.

I have two 5.0AH batteries and two at 6.0AH, so I put one of the 5.0AH batteries in the inverter. I don't have a meter to tell very accurately what happened, but the batteries have four LED lights to indicate the amount of charge remaining. I started at 11:30PM and at 5AM the S9 stopped working. I checked the battery and only one light was still lit. I swapped it for the other 5.0AH fully charged battery, and at 8AM it was down to two lights, i.e., about half charge. Tonight I'll try the 6.0AH batteries and see if they give me better performance, but so far I'm not getting the same results as the users on Home Depot's site reported. One of them said he was using the same S9 VPAP Auto that I have, at 12-20cm (I'm at 15-25cm), and he got eight hours out of a 4.0AH battery with charge remaining. Neither of us use a humidifier or heated hose. I'm not very pleased with the results that I got, but my 5.0AH batteries are several years old, so I'm reserving judgment for now.

This was also my first night with my gently used S9 VPAP Auto, and it was also not a good experience. I set it to the same settings as my Dreamstation BIPAP. In fairness I was having massive mask problems all night long, and this morning OSCAR told me that I was in large leak 37% of the time, so that may have contributed to the discomfort level. My AHI was 4.58, where my Dreamstation averages about 1.5 and rarely gets close to 5.0. 

I'll work on the mask problems today, and I'll try again tonight.

[BB63]

[quote pid='362471' dateline='1597516097']

I have two 5.0AH batteries and two at 6.0AH, so I put one of the 5.0AH batteries in the inverter. I don't have a meter to tell very accurately what happened, but the batteries have four LED lights to indicate the amount of charge remaining. I started at 11:30PM and at 5AM the S9 stopped working. I checked the battery and only one light was still lit. I swapped it for the other 5.0AH fully charged battery, and at 8AM it was down to two lights, i.e., about half charge. Tonight I'll try the 6.0AH batteries and see if they give me better performance, but so far I'm not getting the same results as the users on Home Depot's site reported. One of them said he was using the same S9 VPAP Auto that I have, at 12-20cm (I'm at 15-25cm), and he got eight hours out of a 4.0AH battery with charge remaining. Neither of us use a humidifier or heated hose. I'm not very pleased with the results that I got, but my 5.0AH batteries are several years old, so I'm reserving judgment for now.

I'll work on the mask problems today, and I'll try again tonight.
[/quote]

I've followed this thread with great interest, thanks to all who contributed by posting.

As an electrical person, I find the amount of power used by these PAP's to be appalling! In fairness, they do need to pump a lot of air, which is real physical work. Datalogging consumes a little more power than I previously believed, but I've re-estimated it based on current research done my me. But, it appears CPAPs just suck more battery power than they (probably) should. I recently learned that CPAP's use conventional brushed motors, which wastes huge amounts of power for technical reasons, especially since the load presented by the need for variable speed (variable flow actually) is so dynamic.....and the rotating mass of the motor is so large!

We often have power outages, some which can last for days if the entire East Coast also gets knocked out too, so I was very seriously considering emergency power for my CAP-literally, I CANNOT SLEEP without the CPAP running!!! The ice storm of '98 left us without power for 13 days, with a newborn in the house! My sleep isn't good to begin with, so a day without sleep is devastating for me. It appears I would need at least a 35 amp hour deep cycle battery with a small-ish sized generator to keep the CPAP battery charged. OUCH, there goes the budget::>

Thanks again for all who contributed to this thread!

ABA

[JJJ]

BB63

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We often have power outages, some which can last for days if the entire East Coast also gets knocked out too, so I was very seriously considering emergency power for my CAP

I live in a milder climate than you do, but about ten years ago we got a freezing rain (silver thaw) which gave us about 5cm of ice on everything. Half the city was without electricity for up to a week, although at my house it lasted only three days before they could get it back on. Otherwise my power failures are brief, like some fool wrapped their car around a power pole. 

Still, Murphy says that if I am prepared for such things, they will never happen. I'd rather waste my time and money now in August than in the middle of the winter.

[BB63]

BB63

---

We often have power outages, some which can last for days if the entire East Coast also gets knocked out too, so I was very seriously considering emergency power for my CAP

I live in a milder climate than you do, but about ten years ago we got a freezing rain (silver thaw) which gave us about 5cm of ice on everything. Half the city was without electricity for up to a week, although at my house it lasted only three days before they could get it back on. Otherwise my power failures are brief, like some fool wrapped their car around a power pole. 

Still, Murphy says that if I am prepared for such things, they will never happen. I'd rather waste my time and money now in August than in the middle of the winter.

You're so right JJJ, Murphy is always near!

And, if you wait for a disaster before preparing-it will likely cost you 3 times more! During our survival of the Ice Storm of '98, we got 3/4 inch of ice, telephone poles snapped off under the ice load, sometimes a whole row of them came down like domino's! A family member living just outside the ice storm, and drove 450 miles to deliver a new generator-300 of those miles were through the disaster area. We were lucky! Our White Birch trees all snapped, except for a few that bent over so the tops were laying in ice puddles on the ground.

I plan on preparing now-though the the weather people claimed the ice storm was a '100 year event'.

Enjoy!

ABA