ResMed S9 with a battery?

[B_4]

ttt

Any more news from ResMed on this issue? I am about to buy a 2nd CPAP from second wind for camping because of this.

[Uncle_Bob]

ttt

Any more news from ResMed on this issue? I am about to buy a 2nd CPAP from second wind for camping because of this.

I've seen a S9 price list that inlcudes the following :

S9 Series Parts - 12V DC Power Cord (for "Cigarette" Style Sockets) - Coming soon

[Tip10]

I've seen a S9 price list that inlcudes the following :
S9 Series Parts - 12V DC Power Cord (for "Cigarette" Style Sockets) - Coming soon

Just sent them a note using their Contact Us form on their web site asking if there's any updates on availability. We'll see what response (if any) they give.

[NoUser]

I just asked ResMed about the availability of the DC converter and was told that it's newly available as of today!

[billbolton]

See..... viewtopic/t60506/Resmed-DCDC-Converter- ... or-S9.html

Cheers,

Bill

[mk9]

I've been following this thread for a while as I have a new S9 and am planning trips that require at least one day on battery. I cobbled together a simple measurement apparatus, measured the current used by the S9 (without humidifier) and bought the following which I have tested at home now successfully. Weight and size are important factors as well and the ability to transport and use it on planes is necessary. Prices are current as offered at Amazon.

1) Battery: GoalZero Sherpa 120. 120 watt-hours, lithium ion battery, very well constructed, a bit over 2 pounds: $320. Falls under FAA "larger lithium ion spare battery" rules and can be transported in carry-on luggage (not checked).

2) Tripp-Lite PV150 150-watt inverter, about half a pound: $29 (same as what ResMed sells except doesn't include battery clamps).

This combination runs my S9 (in APAP mode, 11-15 cm) for 8 hours with 20% remaining in the battery pack and the entire package including battery, inverter, cables, S9 and its brick is about 6 pounds. I plan on getting the S9 30 watt AC adapter which is significantly smaller and lighter than the 90 watt brick. While this is heavier than, say, an Everest 3 with battery pack (3.5 pounds), it's a much better machine and you get a general use battery pack with the option (see below) of solar charging.

I too am concerned about the inefficiencies of converting from 12VDC to AC and back into 24VDC and I have measured the standby loss to be roughly 3.8 watts (that is the power used by the inverter + brick combination at 12.5V without the S9 plugged in). That by itself accounts for about 1/4 of the total energy required. The ResMed brick wastes about 2.1 watts doing nothing, the inverter about 1.7 watts. I am hoping that the 30 watt ResMed brick is more efficient.

The new DC/DC converter from ResMed may be a superior solution but since it is sized for the full S9 + humidifier it is large and potentially heavy. I haven't found physical specs on it yet.

In any case the Sherpa 120 battery unit is something I can highly recommend. The same company also offers a large, foldable solar panel for about $300 that can charge the battery pack in 8 hours of sunlight for extended trips off the grid. I didn't get that as I'll only need one day at a time of battery power.

[Glowbug]

Below is a link from Paul C. Buff's website. He manafactures photo lighting equipment and this is one of his newest products. It is a complete very light and small LiPo battery pack/inverter which is a pure sine wave one. It is very hard to get as the photo industry is buying them as fast as he can make them. They are made in USA as much as possible and I own one. I have used mine for the S9 Autoset twice and it should get you ~ 2 nights. I have only used it with the flow generator as the unit is rated @ 120 Watts continuos. I think this is the most portable, light, and best system for CPAP since sliced bread:-)

He had Samlex Inc. build these specifically for his flash units as the capacitors demand high surges that conventional small inverters would not work.

Am I excited about this little power pack...YES I AM!:-) I have no affiliation with him and only own this one product but know how hard it is for us who need lightweight portability in a power supply for our CPAPs.

http://www.alienbees.com/vmini.html

[billbolton]

I have used mine for the S9 Autoset twice and it should get you ~ 2 nights. I have only used it with the flow generator as the unit is rated @ 120 Watts continuos.

According to the web site you linked to, the Vagabond Mini battery capacity is 130 Watt Hours...... that means ~130W for 1 hour or, say, ~10W for 13 hours.

The Resmed Battery Guide (http://www.resmed.com/us/assets/documen ... lo_eng.pdf) indicates that even at the lowest effective titration settings (6cms H20 and EPR3), an S9 is still going to be drawing ~10W, so you'd get a single 8 hour sleep session (but not 2 x 8 hour sleep sessions) out of a fully charged Vagabond Mini. It should also be OK for a single 8 hour session for someone with a 16cm titration (draw ~15W).

The Vagabond Mini is an interesting device, and I can easily see why photographers etc would love it, but it may not meet all CPAP usage needs.

Cheers,

Bill

[billbolton]

but since it is sized for the full S9 + humidifier it is large and potentially heavy. I haven't found physical specs on it yet.

Its in the exact same physical case as the 90W AC mains power adapter and feels to be about the same weight (that is not noticeably heavier or lighter).

Cheers,

Bill

[Glowbug]

I have only used the Vagabond Mini for one night at a time and the battery gauge indicated ~ 1/2 left. The unit comes with the ability to swap batteries, and I have an extra battery if I need an additional night. The battery holds it's charge much longer than a lead acid battery as well. Also, you can remove the battery and hook the unit to a deep cycle battery if desired for longer runtimes which is described in the owners manual.

I use the S9 Autoset @ 4-9 cm so my milage may a little better, but with an extra battery, I can charge the depleted one in my car, or use the car battery to power the inverter if needed. It seems to have a lot of options but as you say, it may not work for every CPAP user but it should work for most.

One more thing about the battery from the website.
"The 14.8V 8.8AH LiCoxNiyMnzO2 Lithium battery pack provides 130 watt-hours of energy and may be discharged to approximately 95% of its capacity before the internal protection circuitry causes shut down. Recycle time of attached lights remains constant from the first shot to the battery depletion point.

By contrast, a 10lb 12V 12AH SLA (Sealed Lead Acid) battery stores 144 watt-hours of energy, but can typically supply only about 60% of its capacity to an inverter system (about 90 watt-hours). This is because SLA batteries suffer from increasing internal resistance as they are discharged. This robs the usable power and causes recycle times to get longer and longer as the battery is discharged. Thus, the Vagabond Mini™ Lithium may be compared, in terms of energy delivered, to SLA systems using 15AH batteries weighing about 12lbs or more."

Weight / Dimensions 3.5 pounds total weight / 2.75” x 4.3” x 7.5” dimensions including battery

[mk9]

Am I excited about this little power pack...YES I AM!:-) I have no affiliation with him and only own this one product but know how hard it is for us who need lightweight portability in a power supply for our CPAPs.

http://www.alienbees.com/vmini.html

Yes, this is a really interesting unit! 130 watt-hours is plenty for my setup and would power an S9 (FG only) for about 10 hours at my settings of 11-15 cm. I use up 80% of a 120 watt-hour battery in 8 hours as a reference, with (as described) about 30 watt-hours of wasted energy in the voltage conversions over that same time. Maybe the Vagabond Mini's overall system is more efficient.

One thing to consider and test with the Vagabond Mini is whether its response to the short current spikes that occur when breathing heavily in at a higher pressure don't result in too big an output voltage drop (a lot of the Vagabond Mini web page talks about this particular dynamic that seems optimized for studio flashes). I measured these spikes to be upwards of 5 A coming out of the battery but for a fraction of a second. The PV150 inverter handles this fine, but a small 130-watt inverter I tried could not, and the S9 would cut out and turn off. In other words, the unit should be tested with a high pressure, a nearly depleted battery, and a heavy inward breath which causes the S9 to pull a lot of current, and see if it all works reliably. I would be really interested in it if so, since it is smaller and cheaper than my setup (but with the Sherpa battery unit, there is the possibility of solar charging).

[bradbev]

I found Michael's post interesting in that I'm into electronics and wanted to build my own 12 to 24 volt converter for my S9. Has anyone investigated the purpose of the third pin that Michael measured at 3.25V ? And of course why his setup didn't work.

We travel in a travel trailer quite a bit and use solar power to charge our batteries. So, I'm looking for the most efficient setup possible.

Brad

Hello everyone,

I plan to go camping next week so I need a 12V DC/DC converter. I measured the voltage on the 3 Pins of the connector the small one is 3,25V one of the bigger ones is GND and the other 24,2V. So I searched for the connector and finally found it at some electronic online shop. By the way its called "MDP-401-3P". Now I bought one Laptop Caradapter supplying 24V till 4Amps and another caradapter for camcorder or cell supplying 3 and 3,3 Volts till 2Amps. Today I combined those two in one housing and so on, it took me about 4 hours of work. The bad thing is that the S9 somehow recognizes that there is something different and writes a message, that I should connect the Powersupply correctly, no matther if i put the small one to 3V or 3,3V. But with the AC converter it still wors fine.
I even can start the flow for a couple of seconds but than it stops, displaying this message.
Has anybody an idea what the reason for this could be? Is the small connector some type of a bus connector sending messages? Are they really that crazy?

Cheers, Michael

[JeffL]

Here's the R#sMed battery operation guide: http://www.resmed.com/us/assets/documen ... lo_eng.pdf

[Glowbug]

The third pin (white wire) is to send a digital message to a chip in the CPAP. The chip in the CPAP identifies the message being sent from the inverter to validate that it is in fact a Res Med sanctioned power supply....So...unless you have a reader to capture the digital message and install it into a chip placed into the third party powersupply to send the correct message to the CPAP, there will be no solution but to buy a Res Med product.

I found Michael's post interesting in that I'm into electronics and wanted to build my own 12 to 24 volt converter for my S9. Has anyone investigated the purpose of the third pin that Michael measured at 3.25V ? And of course why his setup didn't work.

We travel in a travel trailer quite a bit and use solar power to charge our batteries. So, I'm looking for the most efficient setup possible.

Brad

Hello everyone,

I plan to go camping next week so I need a 12V DC/DC converter. I measured the voltage on the 3 Pins of the connector the small one is 3,25V one of the bigger ones is GND and the other 24,2V. So I searched for the connector and finally found it at some electronic online shop. By the way its called "MDP-401-3P". Now I bought one Laptop Caradapter supplying 24V till 4Amps and another caradapter for camcorder or cell supplying 3 and 3,3 Volts till 2Amps. Today I combined those two in one housing and so on, it took me about 4 hours of work. The bad thing is that the S9 somehow recognizes that there is something different and writes a message, that I should connect the Powersupply correctly, no matther if i put the small one to 3V or 3,3V. But with the AC converter it still wors fine.
I even can start the flow for a couple of seconds but than it stops, displaying this message.
Has anybody an idea what the reason for this could be? Is the small connector some type of a bus connector sending messages? Are they really that crazy?

Cheers, Michael

[squid13]

I use this and my battery to run my S9 AutoSet. https://www.cpap.com/productpage/DC-Con ... hines.html