Connecting a CPAP machine to a battery?

For me, breathing warm air reduces the need of the humidifier. If the humidifier is sucking 48F sir I need the humidifier. Because of where I am now in an unheated house I will be sticking the entire machine and hose under my comforter starting tomorrow. Letting the mattress pad normalize the temperature. It's supposed to dip to the high thirties F on Thursday. The humidifier does not stand a chance. For the last couple of weeks the temperature has been slumping. Using half a reservoir of water but I wake up with froze-nose and cheeks.

Been there done that. The Respironics did not even get warm under the covers with the humidifier set on 5. Tongue stuck to roof of mouth 5AM is not my idea of good therapy. So I cranked the mattress pad up to PRE WARM, covered the humidifier and then checked it periodically. Getting overly warm was not part of the program. I sleep with the pad on "2"

And yes I have verified the humidifier is grunting and puffing it's little heart out. 3.9 additional amperes worth. Went to far as to shine the heating pad in the reservoir and under the water reservoir. Even put dielectric grease to aid heat transfer. Tomorrow night under the comforter.

Using it in a van, your most economical method would probably be to add a deep cycle battery of at least 85 and preferably 105 amps, on a battery isolator circuit. You could install the battery under your bed in the back and keep it accessable for removal for outside charging and your vans alternator would recharge whenever you are driving, and the isolator would keep the CPAP from killing your starting battery.

A deep cycle marine Battery would run you less than $100 and the isolators are about $50.
Happy motorin

kerrlakeRoo wrote:
DW and I both use machines, mine is a CPAP without the humidifier, (appears to use about 4 amps per hr) and hers is a BIPAP with the humidifier (uses as much as 7 amps per hr) Both are Phillips units capable of running straight from 12 volts.

If you wear the mask 8 hrs the energy consumed can be as high as 50 amps per night. for a single machine. So how big is you house battery? can it carry that usage without totally depleting the battery?

wow, your AH seem way high. My resdmed using the 12V-24V converter and not using the humidifier, a nights use is less than 8AH, e.g. less than 1A per hour.

my lithium Ion 200WH battery pack will typically last 3 nights w/o the humidifier. 200WH= 15-18AH so going on that again, 6AH/night or less than 1A draw.

Now the humidifier depending on temperatures etc. can run that up to between 2 and 3A/hr or 16 to 24AH/night.

with the humidifier, the battey pack is good for 1 night.

Like Mex points out, Worst case has been when the night time temps drop well below freezing and the trailer drops to 45F at night. the I need the humidifier and it uses the most current, around 3ish A.

My Respironics unit is also older, and uses the same exact 12 volt cord that Tiger4x4RV is using/showing.

Are you in one place? Or are you like me, a bit of a rolling stone?

If you must recharge at your gym, then the best fit may be an LI battery pack.

For regular lead acid batteries to have a long life, they need to be recharged to 100% as often as humanly possible. Unfortunately, the closer they are to 100% the slower the charging rate.

ktmrfs, my numbers were based off what I got from the company website, it may be high due to them going by the maximums, I dont know.
My pressure has been raised twice by the docs, DW's has half a dozen times so I would assume those pressure settings change power consumption. The bricks also show the watt ratings at 12 volts as 60 for mine and 90 for hers.

If your number is a measured number, and his unit is similar, he could use a group 27 battery and a 50 watt solar panel and would have a surplus. phone, laptop ets charging would all be helped.

If you need 12V DC, this Powerstream 12 volt portable battery station probably cost less than what Respironics sells.

kerrlakeRoo wrote:
ktmrfs, my numbers were based off what I got from the company website, it may be high due to them going by the maximums, I dont know.
My pressure has been raised twice by the docs, DW's has half a dozen times so I would assume those pressure settings change power consumption. The bricks also show the watt ratings at 12 volts as 60 for mine and 90 for hers.

If your number is a measured number, and his unit is similar, he could use a group 27 battery and a 50 watt solar panel and would have a surplus. phone, laptop ets charging would all be helped.

I found on both my machines, the mfg ratings are way higher than actual. They usually give a consumption based on power from a 120V line worst case including inrush. since internally almost all are really running of either 12V or 24V there is a conversion loss as well.

I'd bet the 60 and 90W ratings account for the high current needed initially for the humidifier till the water warms up as well, then it drops down to a much lower number.

In any case, the humidifier, if needed, is the biggest power hog. I've found turning it off and filling it with water normally is sufficient.

and yes, I suspect higher pressure has an affect as well.

It would be interesting on your units to hook them to a kilowatt meter and see what it actually draws under various conditions.

I have used both a series one and a dreamstation. Both will run on 12v, with the proper cord, available from your supplier. I have a 12v outlet installed under the bed, which is connected to the 12v coach batteries. I hve run it all night several times, don't have any idea what the maximun time is, but probably can do at least two nights without recharge.

Except for outrageous cost a lithium battery would be ideal for a divorced CPAP battery.

2nd Choice a AGM deep cycle battery life a Lifeline that can see routine 70% depth of discharge (30% remaining) without killing the battery.

Way
Way
Way

Further down would be an RV flooded battery. Reminds me that I have to do some work on the toad. Twin 8 gauge charging cables and a breaker - for road charging the 31 XT Lifeline.

This is where one of Mr. Wizard's, long-ago-recommended inductive DC ammeter/voltmeter setups will be installed.

While traveling in the toad, I overnight at a 24-hour gas station. Reclining seat, Bi-PAP with max humidifier and LED reading light.

The seat tilt is what prompted me to elevate the rig and umbilical house beds by 4" at the head. Reduced apnea events dramatically.