camping and/or backup battery

I've got a ResMed S9 AutoSet on my bedside table. My backup machine is my old Fisher & Paykel HC221LE. I'm going camping for a few (2 or 3) nights. I can't afford a brand new RPS II so I'm considering leaving my S9 at home and packing my Fisher & Paykel HC221LE for which I know "heated humidity can be disabled by setting humidity control (via dial on front) to the "off" region. Not using the heated tubing (on my S9) or humidity would most certainly decrease the drain on the battery thus increasing the hours I'll be able to use my machine away from an electric outlet. More importantly, the cost of the battery backup system to run my F&P HC221LE should be cheaper than the RPS II required for my S9 machine.

I'm no engineer, so here is where I get lost. From what I gather, the F&P HC221LE is for use on a nominal 120V circuit. Don't know what that means but I'm assuming it won't require the $85 DC/DC Converter 24V/90W Output that my S9 needs. Is that all the savings to be had? If so, I'd sleep better with my beloved S9.

Perhaps I should consider a BPS C-100 but I'm intrigued by the plug and play simplicity of the RPS II.

Finally, it would be nice to have a backup battery at home though I can't recall the last power outage. Also, we go camping maybe once every 3 or 4 years max.

Any help on how I can do this without breaking the bank would be greatly appreciated.

are we talking "Car Camping" or are you trying to go light weight and do "Back Packing"???

If weight is no problem you could set up a deep cycle marine battery like I did and have plenty of power. Though I'm still not sure about the heated humidifier.

I use a 110 Amp hour battery and at home I've run it for almost a week just pushing air with no heated humidifier.

If you want to use heat you'll just need to work out the numbers. What's the power drain vs. the capacity of your battery system.

This guy's the encyclopedia of batteries, chargers, inverters etc... check out his posts:
viewtopic/t111214/memberlist.php?mode=v ... le&u=67433

Davidhood wrote:I've got a ResMed S9 AutoSet on my bedside table. My backup machine is my old Fisher & Paykel HC221LE. I'm going camping for a few (2 or 3) nights. I can't afford a brand new RPS II so I'm considering leaving my S9 at home and packing my Fisher & Paykel HC221LE for which I know "heated humidity can be disabled by setting humidity control (via dial on front) to the "off" region. Not using the heated tubing (on my S9) or humidity would most certainly decrease the drain on the battery thus increasing the hours I'll be able to use my machine away from an electric outlet. More importantly, the cost of the battery backup system to run my F&P HC221LE should be cheaper than the RPS II required for my S9 machine.

I'm no engineer, so here is where I get lost. From what I gather, the F&P HC221LE is for use on a nominal 120V circuit. Don't know what that means but I'm assuming it won't require the $85 DC/DC Converter 24V/90W Output that my S9 needs. Is that all the savings to be had? If so, I'd sleep better with my beloved S9.

Perhaps I should consider a BPS C-100 but I'm intrigued by the plug and play simplicity of the RPS II.

Finally, it would be nice to have a backup battery at home though I can't recall the last power outage. Also, we go camping maybe once every 3 or 4 years max.

Any help on how I can do this without breaking the bank would be greatly appreciated.

First I should say I have no experience with F&P cpaps so you should try to verify all of this. I think this F&P runs only on 120V AC power, i.e. there is no simple DC option. This means to use any battery an inverter, which converts DC to AC power is needed. The good news is that they are cheap, easily under $100, but the bad news is they are inefficient so you'll need a larger battery for the same time. To confuse things inverters come in two styles, the cheaper "modified sine wave" and the more expensive "pure sine wave." Odds are good you can get by with the cheaper MSW version.

Now the even better news: once you have this sorted out, the same system will work with either cpap, and even run small appliances. If weight is not an issue, you simply pick a battery sized to your needs, add a charger and an inverter. Prices start at a bit over $100, and $300 would get you a large battery that could run up to a week. Hopefully someone has experience with your F&P and knows about inverter needs and general power usage.

It depends on whether you will be car camping or are looking for something lightweight for backpacking. I'd gone for years without any camping after I got my machine, but now I have kids and decided I need to at least start car camping again. I ended up with the Duracell Powerpack 600, which was only about $125 at the time (the cost of a hotel room night that I didn't need because I was camping!) and is now discontinued...but there are many others batteries like it, that offer both 12-volt DC and 120 volt AC outlets. It's like a car or marine battery, but with a handle, a nice package, and regular outlets (plus a clock, light, and radio). It has been perfect for car camping and lasts me for three nights (at 10 cm pressure with no humidifier). When not in use, I keep it plugged in all the time in the garage to keep its charge, and there have been a number of times when the power has gone out (both planned and unplanned) when that battery has been a life-saver. It also came with jumper cables so that I could start my car if needed...but that option hasn't been needed.