Camping Battery Setup for an Resmed S9 Autoset

I have a GoalZero Escape wall & solar-chargeable battery. I bought a few yrs ago at a Costo roadshow; I also bought a second solar panel for it to reduce recharge time if I needed solar recharging. I bought it for the infrequent power outages we have here in Atlanta. Bet I've used in 6-7 times since I bought it. I check it every 3 months and plug it in if it's low charge. 6 hrs on my APAP (9.8-16, average now around 13) no humidifier uses about 35-40% of the charge. The folks over at tvnation had a video on this unit, not sure how well it'd work on a motorcycle, but camping/sailing in sunlight would work.

A quick look at conversions...

Watts = volts X amps so if you have a 12 volt battery and your xPAP machine uses 5 amps you would be using 60 watts of power.

A 160 watt hour battery would give you a little over 2.6 hours of run time. (160 watt hours / 60 watts = 2.666666 hours)

The question is how much does your machine use?

Guest wrote:I have 120 KWH solar panel kit to recharge it

KWH is the wrong units for a solar panel. 120 Watts would be a reasonable number. A 120 Watt solar panel would be about 6 feet square.

Unless you're going to be backpacking or airplane travel, don't buy the ResMed Powerstation II. You can't charge it with the solar panels unless you have an inverter to generate AC power. It also won't run your CPAP more than one night or so without charging. A car battery sized marine battery or gel cell will be much cheaper and work much longer. You'll also need the $90 ResMed S9 DC adapter. Even that will probably not handle the CPAP for two weeks without charging.

If you've got a good sized 12V battery in your camper, you can just run the CPAP off of that, if you can keep it charged with your solar panel, and if the refrigerator doesn't use up too much of your power. You do need the $90 DC adapter.

You'll also need to figure out how to hook the solar panels to whatever battery you have. It isn't necessarily just a case of hooking the panels to the battery. You really need a charge controller to handle charging a battery from solar panels. This is true even for the battery in your camper.

Whatever system you get, you'll need to figure out how long it will run your machine without charging, or if the solar panels will keep it charged. You also need to be careful with a solar panel. It only gives you 120W at noon, an then only if you've mounted it angled to face south at the right angle. You'll get something like the equivalent of 4-6 hours of full sun per day in the best of conditions.

archangle wrote:

Guest wrote:I have 120 KWH solar panel kit to recharge it

KWH is the wrong units for a solar panel. 120 Watts would be a reasonable number. A 120 Watt solar panel would be about 6 feet square.

Unless you're going to be backpacking or airplane travel, don't buy the ResMed Powerstation II. You can't charge it with the solar panels unless you have an inverter to generate AC power. It also won't run your CPAP more than one night or so without charging. A car battery sized marine battery or gel cell will be much cheaper and work much longer. You'll also need the $90 ResMed S9 DC adapter. Even that will probably not handle the CPAP for two weeks without charging.

If you've got a good sized 12V battery in your camper, you can just run the CPAP off of that, if you can keep it charged with your solar panel, and if the refrigerator doesn't use up too much of your power. You do need the $90 DC adapter.

You'll also need to figure out how to hook the solar panels to whatever battery you have. It isn't necessarily just a case of hooking the panels to the battery. You really need a charge controller to handle charging a battery from solar panels. This is true even for the battery in your camper.

Whatever system you get, you'll need to figure out how long it will run your machine without charging, or if the solar panels will keep it charged. You also need to be careful with a solar panel. It only gives you 120W at noon, an then only if you've mounted it angled to face south at the right angle. You'll get something like the equivalent of 4-6 hours of full sun per day in the best of conditions.

Hi, Thanks for the correction re the solar panel. Yes, 120W. Made by an outfit out of Bend, Orgeon. Has a controller on it. It's two panels, with a hinge between them, so it folds in half. It's about 4 feet by 3 feet. The refurbished units are a nice deal.

re hours of effective sun, at least I'll be in southern utah, and it will be end of April, and there are no trees near any of my campsites, so....I am in decent shape re sunlight. When I return after a day of hiking, I can then turn the car on and use it as a generator. Not great, but better than having no cpap and no fridge. (I don't like to use the car this way, however, as I hate to bother nearby campers. Some of my nights will be spent camping near no one, so....)

I don't plan to buy the ResMed battery, but there is another similar looking cpap battery out there, and I plan to buy that. Maybe two C-100's. IF I am charging the battery at the same time as I am using the cpap, I may need an inverter AND the ResMed DC conveter.....

I am a new user with an S9 and the humidifier and am thinking about the camping problem, so I just went from Google to here.

I read this thread and it is interesting. This won't work for a motorcycle but one would think that taking a fully charged computer UPS would last quite a while. I have not done the math and of course there are all kinds of variables but it might be a good solution. Any ideas on that?

I think the best method is proof of concept so yeah, I'll just try one at home and see how many nights it will last.

Oh yes, one newbie question about taking the humidifier. I guess if it is humid outside it wouldn't even do too much anyway would it?

Greg

Godrunner wrote:I am a new user with an S9 and the humidifier and am thinking about the camping problem, so I just went from Google to here.

I read this thread and it is interesting. This won't work for a motorcycle but one would think that taking a fully charged computer UPS would last quite a while. I have not done the math and of course there are all kinds of variables but it might be a good solution. Any ideas on that?

I think the best method is proof of concept so yeah, I'll just try one at home and see how many nights it will last.

Oh yes, one newbie question about taking the humidifier. I guess if it is humid outside it wouldn't even do too much anyway would it?

Greg

Since you are a motorcyclist, you might want to look at Powerlet.com, who has some packages to allow access to battery power in the motorcycle luggage. Of course, if you can tap into the power system of the motorcycle, you should be able to charge the battery during the day and use the battery to power your xPAP device at night.

Sorry John, I should have made myself clearer. I am not using a motorcycle. I was just alluding to the others that were and that my idea wouldn't work for them because a UPS is basically a BIG battery. I'll be using a van with a tent trailer so carrying something like a UPS isn't a big deal.

Actually, come to think of it, using a UPS at home all the time might be a good idea as it would protect the CPAP a bit and where I live, the power does go off from time to time. It is probably good to think ahead anyway because, man I sure would not want to not have this thing in an emergency. This might be a good idea for everyone to think about. What are you going to do when the power goes off?

You might want to look at the following Battery Backup Design (V2). Even if you only use a UPS, it includes a LOT of information about power needs and how to connect an xPAP device to a battery backup source.

viewtopic.php?f=1&t=89123

By the way, while it's possible to cut the wire for the alarm, most UPS systems include an alarm in the event of a power outage.

Godrunner wrote:Sorry John, I should have made myself clearer. I am not using a motorcycle. I was just alluding to the others that were and that my idea wouldn't work for them because a UPS is basically a BIG battery. I'll be using a van with a tent trailer so carrying something like a UPS isn't a big deal.

Actually, for CPAP use, most home or office UPSs are small batteries. You might get a few hours. You need to figure out the watt hours the UPS will provide and calculate the run time.