My battery backup setup

[OMyMyOHellYes]

I said it was "basically" a USB cable, as in meaning no electronics involved. As you described it fits my meaning exactly. The manufactured cost of that cable is close to a USB cable. To give them the benefit of the doubt lets say it costs $5 and they sell it for $40 provides them an 87.5% profit margin.

As for Resmed at least they have a boost converter in the cable.

Comparing a USB cable to a 16 ga wire assembly is like comparing a dad-gummed Toyota Prius to a Kenworth tractor. It is just silly. Following the USB logic, we could just a easily say that the main lines bringing power off the transformer to the house is a USB cable. Enough of that nonsense. If you want to draw a comparison, an extension cord would be better than a USB cord. But it would be a fancy extension cord. So what if the cable is cheap to manufacture? I bought one and sent it back because I thought it was a stupid design anyway.

And rather than praising the overpriced Resmed piece of, well, fertilizer (which also probably has direct costs of less than $10 to manufacture), the question should be "Why the frack does Resmed make products that require one? And when they do, why do they add insult to injury by requiring that you buy their stupid cord with their stupid box with the 'boost converter'?"

OMMOHY

[PoolQ]

Obviously we are not making a connection on this communication. I stand by my statements and you of course are free to disagree. I will leave it at that. Have a nice day.

[Richard3r]

have you done this? used two batteries? can you provide details on equipment and how to do this? thanks

[Richard3r]

so, how often do you have to charge these batteries? thanks

[Richard3r]

can you provide details of your setup so I can copy please?

[justMongo]

OMMOHY has a PR system which is 12 Volts. He has an elegant way of using a Schottky diode bridge as a switch-over from charge to providing power directly to his PR machine.

For the 24 V Resmed machine -- best bet is to buy their 12V to 24V up converter; buy a 12V SLA (Sealed Lead-Acid) Battery in the 35 Amp-Hr or greater range; and put it on a Battery Tender. Search for Battery Tender on Amazon.

[Richard3r]

thank you!

[drgrimes]

        Not sure if anyone has already posted this. It is a simple approach, that some told me it would not work but it does. I was able to run S9 for three nights. This unit is rechargeable by 110 or 12v. The battery jumper unit is available at Wallyworld for about $70 and the 12v to 24v converter is avail. from Amazon or cpap suppliers for $50-70.

Pretty handy, has usb charging built in, a small flashlight, and can jump start your vehicle if need be.

[justMongo]

The SLA in that unit is around 15 Amp-Hr; and the built in charging circuit is crap.
Sure it will work.

My choice is: 12v, 35 AHr, SLA

plus: 12V, 5 Amp, Battery Charger/tender.

plus: ResMed 12V to 24V converter.

plus:

plus (optional)

[verbatim1]

I've found that the A10 will run from a +24 volt power supply (non-ResMed) when the center pin is connected to +3.3 volts thru a 2.7k ohm resistor. I use a +3.3 volt three-terminal voltage regulator fed from the +24 volt power supply. The resistor functions as a pull-up resistor to +3.3 volts and tells the cpap the power rating of the supply. I've tested this on two units.

Hi Steve,
I just found out about the non-standard voltage and signal line of the A10, and was wondering if you have current (or power) requirements scoped out?

For example, what is the current sourcing need for the 3.3VDC voltage regulator?

For example, the LD1117V33 listed here [direct commercial link removed] or the LD1117-3.3 TO-220 listed here [direct commercial link removed].

Less important than the power of the voltage regulator is the wattage of the resistor.

Will a typical 1/4 Watt resistor do?

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