Xantrex + BiPAP Auto with Biflex: A report on usage

If you own the XANTREX 400 Powerpack AND the Respironics BiPAP Auto with Biflex:

Have you used both together: what has been your experience with the two: please give IPAP and EPAP pressure settings and useable time from battery at those pressures.

Respironics say they cannot give me amp output at different pressures.. So how does CPAP dot com do it when they give usage time for Respironics battery pack for different machines at different pressures? So I am just curious how things have ACTUALLY worked out for you with the XANTREX 400 Powerpack AND the Respironics BiPAP Auto with Biflex.

I know there are better performance batteries and setups out there. I like the convenience of the sealed battery with incorporated charger and dc output. Nice, neat, easy. S hopefully, the Powerpack 400 has givenyou good performance for one night or two. Hope to hear from you.

Thanks

BML

Here is my rather long Initial Report on my experience to date with my XANTREX 400 Powerpack AND the Respironics BiPAP Auto with Biflex.

Brief and to the point


The XANTREX 400 Powerpack has a 22 amp hourAGM battery. I used the powerpack with my xPAP for 3 consecutive nights. It had been initially charge (out of the box) for 72 hours prior to use. The powerpack was recharged fully between each night of usage.

For these 3 nights, my average IPAP was 11 and my average EPAP was 9. There were no large leaks and my average leak was below 40 liters per minute. The C-Flex setting remained at 2. The humidifier was disconnected from a power source and used as a passover humidifier. My AHI hovers around 5 though my time in apnea per night fluctuates from 7 to 14 minutes.

I woke up every morning to a depth-of-discharge of 80%; in other words, my remaining capacity was 20%. Not once did the powerpack shutdown prior to the end of the night. My average night was 7.25 hours running time on the xPAP.

Conclusion: I was hoping for a better performance from the powerpack but I did successfully complete 3 nights sleep without ever being cut short. Recharging took l0-12 hours per day. I am hoping to make a powerpack my power supply for the xPAP on camping trips. I will probably need to get a second unit to camp out 2 nights+.


Why the XANTREX 400 Powerpack ?

Convenience: A sealed AGM battery and a charger combined into one small 22 lbs package. I feel that the unit can be safely left in the house to charge and be used. Easy to carry and store. Could have a unit at home and one at the girlfriends house to make it through a blackout. On sale, (98$can) it was a good deal.

In campgrounds in my area, a site with electricity is 6$ a night. This unit will pay for itself after 16 days of camping. Often, there are no sites with electricity in the campgrounds we select and the powerpack gives you the option to pick your site based on other factors than proximity to a power source. For me, that was very important.

I know many of you prefer the power and performance of larger marine or deep-discharge batteries. I have read these discussions on this site and elsewhere. Again, this was my personal choice balancing cost, convenience and expected return on investment within a relatively short period of time.

Nevertheless, I thought I would get more mileage out of this powerpack using calculations that are described in the next section.


Bernard

Part 2: Using the Xantrex Powerpack 400 and a Respironics BiPAP Auto with Biflex

Using the CPAP.com Respironics Battery Pack page to calculate Battery Performance based on machine pressure

https://www.cpap.com/productpage/produc ... andbattery

Machine Pressure and Battery Performance
Machine: M Series BiPAP Auto with BiFlex
Pressure Setting: Inhale 11 Exhale 9

CPAP.com Battery Pack
10.00 hrs (Battery Weight 2.5 Lbs.) *
Respironics Battery Pack
21.21 hrs (Battery Weight 12 Lbs.) *
* These times are estimates, we do not guarantee hours of operation
** When an inverter is included in series with the battery and the machine, battery life time will be reduced by approximately 1/2 due to power usage by the inverter itself.

Above you see the utility available on that page to estimate battery performance. I used my machine and my average pressures and determined a run-time of 21,2 hours using the Respironics battery pack that has a 14 amp hour battery according to the Respironics site.

http://global.respironics.com/UserGuide ... nglish.pdf

Using, perhaps flawed logic, I extrapolated that if one could get 21.2 hours use from a 14.4 amp battery, one could get 29.4 hours from a 20 amp hour battery. This is not what my results indicate; I got 7.25 hours at best before reaching a depth-of-discharge of 80%.

So either, the utility on the CPAP page is very flawed despite the warning that * These times are estimates, we do not guarantee hours of operation. How far off can an estimate be? Or, the battery used in the Respironics battery pack is quite different from my AGM battery in the Xantrex Powerpack? Or, the C-Flex settings on my machine have something to do with it (don’t think so)? Or, ... I don.t know... you tell me

I contacted Respironics and their only answer was max 3 amp output on DC current. They do not estimate power usage at various pressure settings. I don't know how CPAP.com derived these estimates and what they are based on. They may be more or less accurate depending on the machine xPAP. I am only commenting on my use (perhaps flawed) of this little utility.

My point: Be careful, if you use this utility as others have before me to estimate running time of your xPAP on a selected battery. Of course, accuracy may vary with the xPAP you select. Or, somebody tell me where I went wrong! 


Bernard

And finally:

Other ways to measure power output and estimate battery performance

I had also found this post:

viewtopic/p367758/viewtopic.php?f=1&t=3 ... nt#p298836

Quote>>>
I measured the 12v DC power used by my Respironics M-series Auto machine. This data may be useful if you are designing your own battery backup or estimating how long a battery would last.

Note 1. The power consumption goes up as the flow increases, for a specific pressure. This means when there are leaks the power needed will increase too. The measurement data below was done with a Switf LT nasal pillow, when there is no unintended leak.

Note 2. There is a very high initial current needed when flow starts, for a couple of seconds. This may be as high as 2A. If the voltage drops even 0.5v at that initial time (below about 12v), the machine simply will shut down the flow!!

Note 3. This is not for the 110v AC side of the power brick, people using UPS like boxes cannot use these numbers directly.

Note 4. The humidifier is always off for these, since the humidifier does not work on 12v DC, but needs 110v AC.

Edited: The following was measured at approximately sea level.

Current Pressure
mA cm
~320 4.0
~360 7.0
~390 10.0
~420 13.0 (estimated)

When the above mask is taken off, (when air is freely flowing from the pillows), the consumption will go up to about 1 Amp.
When the blower is not running, it takes about 200 mA.

So with the varying unintended leaks we always have, and the variations in the intended leaks of different mask models, I estimate the average consumption may be about 400-700 mA, depending on your pressure, leak, mask type.
>>>>Endquote

This also gave me hope but has not proven to be reliable for my particular setup.

Cycling the battery to improve its performance?

I read somewhere else on this site ( I am still looking for the exact reference) that most batteries need to be charged and discharge at least 20-25 times before they reach their peak performance. If this is true, i may get up to 2 nights from one Xantrex powerpack at some point. Time will tell. I will continue using this setup and give you an update if my battery performance gets significantly better. Hope this was of some interest to you.

Bernard