Solar Charging Battery Pack

I travel in the bush in Africa without access to power. I use an Anker solar charger to charge a battery to support my computer, camera, etc. is there a battery that I can solar charge that will support my philips dream station (AC input) I don’t use the humidifier or a heated hose. There is plenty of sun so daily charging is not a problem. Thanks.

WAB1960 wrote: ↑

Wed Jun 20, 2018 8:20 am

I travel in the bush in Africa without access to power. I use an Anker solar charger to charge a battery to support my computer, camera, etc. is there a battery that I can solar charge that will support my philips dream station (AC input) I don’t use the humidifier or a heated hose. There is plenty of sun so daily charging is not a problem. Thanks.

First, the dreamstation actually runs on 12 volts DC, and you should get the 12V power cord for about $30. This will allow you to run from any standard 12v battery, such as deep cycle. This will save a considerable amount of power compared to using an inverter to feed the AC input.

You're correct that it would be nice to charge a battery with solar power during the day and then use that collected power to run the cpap at night. However, its not as simple as connecting any solar panel to any battery - the voltage has to be compatible. So it would be necessary to know the model of the panel to advise further.

I will say that the cpap pump will use roughly 50 to 75 Watt-hours per night, so a small panel, such as the Anker 21 Watt panel, will need 3-4 hours of good collecting to keep up. If this were in the US NorthEast, I'd say this is rather marginal, but with more consistent clear weather and fewer trees, it could work out. The other problem is that I think the panel is designed for a 5V output, but you'll need to run the cpap on 12V, so this is an issue.

Also, it would help to know your needs for weight. Many users of these small panels are hiking, and would need a small, lithium pack which is really only good for one or two nights. If, however, you can handle more weight, you can get a larger more traditional (and cheaper) battery. This could be matched to a wide variety of panels, and perhaps the one you have.

For more info, refer to the link in my signature.

For 12 volt CPAP emergency power here in the US, here is what I currently have.

100 watt solar panel kit: https://www.harborfreight.com/100-watt- ... 63585.html

12 volt 35 AH AGM battery: https://www.harborfreight.com/12-Volt-3 ... 68680.html

I am looking to upgrade our 4WD pickup camper to support our two new DreamStations. We often primitive camp at about 10,000 ft in the Colorado Rockies. I'd like to keep it simple for now, with a portable 12V solar panel (suggestions?) and perhaps replace the single 12V battery with a couple 6V deep cycle units (more suggestions?). Note the camper batteries do have other uses, like LED lighting, keeping the LP gas refrigerator electronics alive, etc. Just now researching, although we are planning to go CPAP-less camping again this weekend! I am sure we will survive maybe with some brain cell loss. I am a degreed electronic engineer and feel quite comfortable about most that I have read here, especially from CapnLoki. Good stuff, and well researched.

Am I correct in understanding that a simple 12V cigarette lighter adapter can not be used with the DreamStation? Some "special" adapter must be used to fool it into believing an "approved" power supply is being used?

duncpilot wrote: ↑

Wed Jun 20, 2018 2:21 pm

I am looking to upgrade our 4WD pickup camper to support our two new DreamStations. We often primitive camp at about 10,000 ft in the Colorado Rockies. I'd like to keep it simple for now, with a portable 12V solar panel (suggestions?) and perhaps replace the single 12V battery with a couple 6V deep cycle units (more suggestions?). Note the camper batteries do have other uses, like LED lighting, keeping the LP gas refrigerator electronics alive, etc. Just now researching, although we are planning to go CPAP-less camping again this weekend! I am sure we will survive maybe with some brain cell loss. I am a degreed electronic engineer and feel quite comfortable about most that I have read here, especially from CapnLoki. Good stuff, and well researched.

I have 4 6-volt batteries (Trojan T-125) which are very good, but the choice was driven by the available space in the battery box. There is nothing special about 6 volt as opposed to 12 volt, and there are plenty of other possibilities - I would consider an AGM if there's any chance you'll be moving them around. What counts is the total amp-hours. Remember that 6-volt amp-hours only count for half.

Assuming you don't use humidity, the load of the two pumps is relatively small for a camper setup - similar to a computer and small TV. if you plan to use humidity and heated hose, you have to be planning for an extra load - up to 30 amp-hours for each machine. If you're planning short trips, just load up on enough batteries to cover the trip. If you want to stay off-grid for an extended period you want enough battery power to go at least three days, and recharge daily. The protocol is: discharge to 50%, recharge to 85%.

My life got much easier when I added 2 100 watt panels. If you can't permanently mount a panel, you might look for a flexible 100 watt - the price should be under $200 now. Figure that a panel will collect an amount equal to 3 to 4 hours of running, so a 100 watt collect 300 to 400 watt-hours, or 25 to 32 amp-hours a day, on average. I use a MPPT controller which boosts the power about 20%.

duncpilot wrote: ↑

Wed Jun 20, 2018 2:21 pm

Am I correct in understanding that a simple 12V cigarette lighter adapter can not be used with the DreamStation? Some "special" adapter must be used to fool it into believing an "approved" power supply is being used?

That was not the case with the previous versions, but I believe that the current version does require a special cord. However, it is only $30, and is fused with chokes, and is heavy duty so its reasonable value.

Somewhere I thought you posted an average of 12-24 watts for pump only use, thus 96-192 Wh needed for 8 hour sleep. Is the 30 Ah (thus 36 Wh) you cited just for the additional humidifier and/or heater draw? Otherwise I should plan batteries for about 192 x 2 = ~400 Wh, or 33 Ah capacity using a 12 V source to supply two CPAP machines. Thus two 6 V @ 70 Ah batteries, right? Or plan 66 Ah to allow for the 50% max discharge value?

I see several 100 W flexible solar panels < $200 on Amazon. Would these be generally rugged enough for minimal off-road use? I was thinking about foldable panels, like the pricey Goal Zero Nomad series, to store inside camper and then place outside at good angles/locations once camped. Am I correct in assuming these flexible units will not "roll up" very tightly for storage.

duncpilot wrote: ↑

Wed Jun 20, 2018 4:57 pm

Somewhere I thought you posted an average of 12-24 watts for pump only use, thus 96-192 Wh needed for 8 hour sleep. Is the 30 Ah (thus 36 Wh) you cited just for the additional humidifier and/or heater draw? Otherwise I should plan batteries for about 192 x 2 = ~400 Wh, or 33 Ah capacity using a 12 V source to supply two CPAP machines. Thus two 6 V @ 70 Ah batteries, right? Or plan 66 Ah to allow for the 50% max discharge value?

I see several 100 W flexible solar panels < $200 on Amazon. Would these be generally rugged enough for minimal off-road use? I was thinking about foldable panels, like the pricey Goal Zero Nomad series, to store inside camper and then place outside at good angles/locations once camped. Am I correct in assuming these flexible units will not "roll up" very tightly for storage.

The specific measurement I've often quoted is 4 Amp-hours a night for my Philips 560 at pressure 10. This is a fairly efficient pump, so others might be a tad more. This is at 12 volts, so its about the same as 48 Watt-hours a night, which is why I quote between 50 and 75 w-h if the pump and pressure is not specified. Humidity and heated hose can run the worst case load up to 5 amps or 40 amp-hours or 480 watt-hours for a night. This is in line with the 90 watt power supplies.

You have to form a budget - say 5 ah for the pump, maybe 10 ah for humidity, times 2 is 30 ah. Add in other loads maybe 20 ah for a total of 50. By my protocol this would mean a battery bank of 150 ah. If your primary charging is solar you'll want more than 100 watts, unless you're in a desert. Whenever you rely on solar you need a backup plan for when its rainy, perhaps a small genset. Obviously, if you don't use humidity and minimize other loads, this gets a lot easier. BTW, my load is around 100 ah a day.

I haven't used a flexible panel in a long time. They are pretty tough - the ones I used could be put on the deck and walked on. They are flexible enough to be put on a curved surface, but not so much that they can be rolled up. I stashed mine under the mattress.

The reason for the discharge to 50%, charge to 85% protocol is that you won't be able to top off the batteries in a limited amount of time. You could push that by discharging down as low as 20%, but is limits the life of the battery.

I'm not sure why you mention 6 volt batteries - do you a special deal on them?

CaptLoki - Have you found any oxygen concentrators that might be used/modified for use with battery power with a CPAP?

duncpilot wrote: ↑

Wed Jun 27, 2018 1:31 pm

CaptLoki - Have you found any oxygen concentrators that might be used/modified for use with battery power with a CPAP?

There are lots of portable, battery powered concentrators. They're just expensive.

Palerider - agreed. However I am looking for something that can use 12V input for 8 hours at night, then keep that battery charged via solar panels per previous posts. As example, the Phillips SimplyGo appears to have a 12-16V input, spec'ed at 18A max. I'd like to know what "average" consumption is, say at 2 LPM, and how this compares to the other portable oxygen concentrators on the market. This is needed to size my planned battery & panel needs. I am hoping Medicare will help with the concentrator, while I fund the battery/panel system.

duncpilot wrote: ↑

Wed Jun 27, 2018 1:31 pm

CaptLoki - Have you found any oxygen concentrators that might be used/modified for use with battery power with a CPAP?

Sorry, I don't know much about oxygen concentrators. The last time this came up someone was looking for a multi-day solution and I thought that would require a large battery bank. My advice was to consider a rental tank. If you have a better idea, we'd like to hear it.

duncpilot wrote: ↑

Wed Jun 27, 2018 2:14 pm

Palerider - agreed. However I am looking for something that can use 12V input for 8 hours at night, then keep that battery charged via solar panels per previous posts. As example, the Phillips SimplyGo appears to have a 12-16V input, spec'ed at 18A max. I'd like to know what "average" consumption is, say at 2 LPM, and how this compares to the other portable oxygen concentrators on the market. This is needed to size my planned battery & panel needs. I am hoping Medicare will help with the concentrator, while I fund the battery/panel system.

The Respironics battery pack that I found for the SImplyGO is listed as three hour, 14.4 volts, totaling 98 Watt-hours. That would imply 300 watt-hours are needed to go a full night. This would be a rather expensive lithium pack, but is only 25 amp-hours at 12 volts, or about the useful power from a 25 pound AGM scooter battery. Or its possible that a larger 100 amp-hour would cover 3-4 nights. Of course, its not clear the 12 volt output from an AGM would power the device.

As for recharging with solar, to recover this amount on average you'd need a 100 watt panel, and hope that you'd get consistent sun. The larger battery would increase the chances of making through a rainy period.

Hi All,
I am new here. I am getting ready to travel overseas. I am thinking about getting a HDM Z1 to reduce my over all weight and size. This is also in preparation to going backpacking.
...Now,..do I have to buy the crazy expensive "PowerShell battery set up?? ...or can I use something like Anker Powerbanks to supplement my power source? Are these compatable? And are these enough power?

https://www.anker.com/store/powercore-20100/A1271012

Thank you in advance.

"Not an engineer" RJ

rjfoodman wrote: ↑

Thu Jun 28, 2018 2:30 am

Hi All,
I am new here. I am getting ready to travel overseas. I am thinking about getting a HDM Z1 to reduce my over all weight and size. This is also in preparation to going backpacking.
...Now,..do I have to buy the crazy expensive "PowerShell battery set up?? ...or can I use something like Anker Powerbanks to supplement my power source? Are these compatable? And are these enough power?

https://www.anker.com/store/powercore-20100/A1271012

Thank you in advance.

"Not an engineer" RJ

This cord should allow you to use any 12 volt battery, within reason.

https://www.cpap.com/productpage/human- ... -cord.html

According to the unobtainable battery page here https://www.cpap.com/productpage/human- ... -cord.html

a 14.4V 45 Wh battery should last at or 8 hours at 14 cm. the range given is from 4 to 14 hours.

prodigyplace wrote: ↑

Thu Jun 28, 2018 7:00 am

This cord should allow you to use any 12 volt battery, within reason.

https://www.cpap.com/productpage/human- ... -cord.html

According to the unobtainable battery page here https://www.cpap.com/productpage/human- ... -cord.html

a 14.4V 45 Wh battery should last at or 8 hours at 14 cm. the range given is from 4 to 14 hours.

You seem to have the wrong link for the "battery page."