Batteries, BiPaps, and Really High Pressures

Well, I have spent literally hours now reading all about batteries here at cpaptalk.com, and I still have questions!!

I have a very high pressure (20cm), and am consequently going to be getting an auto-bipap soon. I'm still unsure as to which battery I should get, because the Respironics M Series BiPap Auto that I am looking at runs at 24V, not the 12V that CPAP's use.

I am interested in a Xantrex or something similar that is an "all-in-one" unit. I'm willing to pay more for the convenience. I'm just not sure which model is appropriate given the fact that I will be using a BiPap Auto and have very high pressure. Also, I tend to sleep a lot so I want something that will let me go a good 10 hours strong. I don't need it to last for more than one night because I can just charge it from my car during the day.

Thanks to everyone for your advice! Happy sleeping!

P.S. My Dr. gave me some Ambien yesterday and I think that I am having a paradoxical reaction. After 30mg I am WIRED!

30 mg?????

I was told that 10 mg is the "normal" dose and 20 mg the max. Sleep lab doc wouldn't let me take more than 15 mg the night of my titration....

Mindy

Anonymous wrote:30 mg?????

I was told that 10 mg is the "normal" dose and 20 mg the max. Sleep lab doc wouldn't let me take more than 15 mg the night of my titration....

The prescription is for 10mg but I was being bad. I took one, waited two hours and nothing, so I took another and waited another two hours, then I took another. Still nothing. I am not going to take any more of that crap!

Bert,

First, do some math. You need to know how many amps your bi-pap will pull at 20 cm. I would guess somewhere in the neighborhood of 3 amps, but you need to check. It may be more. Not likely much less.

Multiply the amperage draw times your 10 hours sleep per night. 3 amps X 10 hours = 30 amp-hours.

You don’t want your battery to be drawn down much more than 50% before recharging, else it will have a very short life. Therefore, double the battery capacity to find what is necessary. 30 amp-hours X 2 = 60 amp-hours.

You need a battery of at least 60 amp-hour capacity, based on an assumed 3 amp draw from your bi-pap.

I’m not sure what Xantrex you’re considering. The Xantrex XPower Powerpack 1500 has a 60-amp-hour battery. Anything less won’t do what you want.

According to its data sheet, the Xantrex XPower Powerpack 1500 takes 6 to 8 hours to recharge from a car. Running the V-8 at fast idle in the driveway for 6-8 hours is not the most efficient way to charge a battery, and it’s bad for your car, too. (Look at the 1500 and you’ll realize it is impractical to plug it into your cigarette lighter socket while you commute.) Better to get a small generator or 100-watt solar panel to recharge.

I find a deep cycle battery and a battery box more convenient, and a lot less expensive.

Wayne

On edit: BTW, the above is assuming you will be using the bipap with the 12VDC adapter from Respironics and without the heated humdifier.

If you want to run the bipap on 120 VAC, the Xantrex Xpower Powerpack 1500 may not be enough power, since you’ll have to use the inverter feature to get 120 VAC. How many amps does the bi-pap draw on household current? Multiply times 120 to get the number of watts it pulls. Compare this wattage draw to the chart in the data sheet to find out how long it will run your bi-pap. I’m guessing maybe 3 hours, much less with heated humidifier. (Inverters are inefficient.)

BigGayBert wrote:I have a very high pressure (20cm), and am consequently going to be getting an auto-bipap soon. I'm still unsure as to which battery I should get, because the Respironics M Series BiPap Auto that I am looking at runs at 24V, not the 12V that CPAP's use.

I have the R M Bi Auto and got the Resprionics battery. (where do you get the 24V???? it's a 12)

I run at 19cm, and have gotten 9-10 hours out of the battery. BUT that is without the heated humidifier. (make sure the humidifier is set to 0 ) It works Ok as just a by-pass humidifier when camping or such.

I had wanted the Geek product, but they were out and I was leaving the next day camping, so took what they had in stock. I re-charged it from 110, so dont know how it will go trying to re-charge from the car, but you can always get a converter to charge it.

msheda wrote:. . . but you can always get a converter to charge it.

You still need a source of power. Generator, solar panel, whatever.

Letting a car’s engine idle for 10 hours (Respironics battery pack charge time) every day to charge a battery is wasteful and does the car no good.

And if you mean inverter, they are very inefficient. They waste as heat about half the power they use. (Notice the cooling fins?)

If you don't let the car idle, it will also drain your car's battery.

Wayne

I have the R M Bi Auto and got the Resprionics battery. (where do you get the 24V???? it's a 12)

Some of the Respironics BiPAPs run on 24 volts, but I am not sure about the M.

Yup, meant inverter... don't know, I dont have one.

The M-Series Bi-Pap Auto that I have is 12 V, that is why I was questioning it since that's what he seems to have been talking about.

I'm just going by the Cpap.com website. I haven't actually seen the machine in person so I don't really know. =)

"# AC Voltage Source 100 to 240 V, 50/60 Hz
# DC Voltage Source 24V (when operated with the external DC power adapter accessory)"

https://www.cpap.com/productpage-advanced.php?PNum=2335

Thanks, everyone, for your responses. Very helpful!

I see the reference on the cpap.com product page to 24 VDC, but it also mentions the Respironcs DC power cord for 12 VDC operation. Confusing. And probably wrong WRT the 24 VDC reference.

According to the User’s Manual (see page 3-6) the BiPAP Auto M takes the Respironics DC Power Cord to run from a 12 VDC battery. However the power may be converted internally, it runs off of a 12 VDC power source. No need to worry about a 24 VDC power source.

To run straight from a battery using the Respironics DC power cord, you’ll need a battery clip to cigarette socket adapter. The Respironics version costs another $25. Go to Radio Shack and get one for $7.00.

Wayne

The Better built BiPAPS run on 24 volts, because BiPAPs work harder than Cpaps. It use to be BiPAPS were rated to 30 CM. Now some of them are rated at 25 CM. You could call this progress, I call it cheap. Jim

Bert, get an AGM battery, size large if you can afford it. I went to Batteries Plus for a generic house brand, 12 Volt, 80 amp hour. Then I went to Harbor Freight and bought a 400 watt inverter. And I plugged my unit in.

I have a device called "Kill-A-Watt" that tells me what the actual power consumption is. I use the Respironics BiPap Auto SV, with HH turned on and I think it drew around 65-90 watts. Just the BiPap Auto SV running, no HH and it is around 35-50 watts. I think the SV pulls more power than other units, with pressures of 30 for minutes at a time.

Pep Boys, Kragen (Checkers, etc.) or Harbor Freight (on the web if nothing else) have inverters. Respironics told me the 400 watt inverter was plenty.

The AGM has no water to spill (with acid in it), no explosive gases to explode but it is more expensive. That is why I recommended a reputable place like
Batteries Plus.

Good Luck

Inverters will work well, and if you need to run the heated humidifier they are the only solution for running off a battery.

Be aware, however, that running an XPAP with an inverter will consume about twice as much battery capacity as running with the XPAP maker’s DC power cord. As I said before, inverters are very inefficient. You will have to spend about twice as much time recharging the battery. Or recharge the battery twice as often.

With an inverter you are converting 12 VDC to 120 VAC, then the XPAP converts 120 VAC back to the 12 (or 24) VDC that the XPAP really runs on. I prefer to minimize the changes in voltage.

When camping, I use an inverter to run a boom box. It needs 9 VDC and 6 C batteries last only 4 or 5 hours. I have 220 amp-hours of battery capacity (golf cart batteries) in the camper and I run a generator every day or two to recharge them. Using the extra battery power for the inverter and boom box is almost a non-issue for me. But I run my REMstar Auto on 12 VDC using the Respironics DC power cord.

Last summer, I went to one of those fly-in fishing camps in Canada for a week. I bought the 75 amp-hour deep-cycle battery to run the APAP for that trip. (The two 6 VDC batteries from my camper weigh about 140 pounds.) I’ve also used this battery in the house during a power outage. I charge it in the garage or on the back porch, not the bedroom, so off-gassing during charging is a non-issue.

Wayne