)First - your need: 3 nights with average pressure of 7.5 will be only 15 Amp-hours if you can go without humidity. This could be handled by a 20 AH AGM battery - 12 pounds and $40. A bit heavier than the high priced lithium offerings, but a LOT cheaper. I would (and did) go up a size to the 35AH AGM -its a luggable 24 pounds, but another overkill solution is to just get a second 20AH.ducker wrote: ↑Mon Apr 02, 2018 3:26 pmOk... CapnLoki - you've pretty much single handedly brought me to registering and posting on this forum
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Larger, heavier batteries aren't a option.
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In a nutshell -- I want a battery that lasts 2-3 nights of approx 6-7 hrs, with out heat, preferably with humidity (I haven't tested at home if I would mind w/o the humidity yet)
The flexibility to possibly go longer than 2-3 nights either via solar charging, or plugging in to charge during the day. (ie. Scout Camp in the summer)
I personally feel, I could just go with out the CPAP machine, for a long weekend, but I would rather stick with it! Haven't missed a night since the first day I received it.
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This is a long thread and I admit I have not read it all. I have found the ResMed Battery document very helpful in sorting out requirements to run on battery power. See this link:ducker wrote: ↑Mon Apr 02, 2018 3:26 pmIn a nutshell -- I want a battery that lasts 2-3 nights of approx 6-7 hrs, with out heat, preferably with humidity (I haven't tested at home if I would mind w/o the humidity yet)
The flexibility to possibly go longer than 2-3 nights either via solar charging, or plugging in to charge during the day.
Yes, the battery you linked to should be fine. I also like the Universal Battery brand - they have the UB12220. The extra stuff needed is listed in the 12th post of this thread, on the first page. Basically its a BatteryTender charger which comes in three sizes. This is a high quality trickle charger, very gentle on the battery. It comes with all of the cables needed except the "cigarette lighter socket" which is under $10. The socket will accept the ResMed converter (or the Respironics 12V cable, or an inverter if you're so inclined). I like a box, but you can also use "boots" to protect the terminals which should not be left exposed. You can get by with under $80 but I think most would go a size up on the battery and charger, so for most the tab would be about $120. The charger of coarse doesn't have to be carried in, only the battery, cable and converter.ducker wrote: ↑Tue Apr 03, 2018 12:36 pmThank you so much for the reply CapnLoki!!
Do you have an suggestions for a 20 AH AGM battery? (something like THIS? )
The reason I was looking at the Yeti - was that it had the window dressing (the different connections)
So if I did go with a standard AH AGM battery what assorted accessories would I need to make this work?
I'd think I would need a few different adapters/connectors for the 20 AH AGM battery, outside of the CPAP DC converter. As I'm camping in a tent, I don't really want to have to also manage a bunch of wires on top the hose of the CPAP. I just see myself getting frustrated at the whole setup.
Your comment to get the converter to save $ and lbs. How exactly? Are your tentative numbers taking the converter into account? Because I'm not excited about the idea of carrying around another 10-15lbs in a backpack for a 20 AH AGM bettery
What would you suggest for a lithium battery that would last approx 2 days? I'm expecting that the majority of use cases will be where I am camping just Friday / Saturday night.
And/or will have the opportunity to charge via a plug typically during the day. Based on your estimation, it looks like I need ~ 5 AH a night (with out heat or humidity) that battery I linked COULD do it, but I would have to charge it every day for the next time. I'd rather have a bit more flexibility in the amount of power stored in a lithium battery.
Again, thanks for your input I greatly appreciate it!
I've been trying to follow along and think I may be okay, but wanted to double-check.CapnLoki wrote: ↑Tue Apr 03, 2018 3:19 pmYes, the battery you linked to should be fine. I also like the Universal Battery brand - they have the UB12220. The extra stuff needed is listed in the 12th post of this thread, on the first page. Basically its a BatteryTender charger which comes in three sizes. This is a high quality trickle charger, very gentle on the battery. It comes with all of the cables needed except the "cigarette lighter socket" which is under $10. The socket will accept the ResMed converter (or the Respironics 12V cable, or an inverter if you're so inclined). I like a box, but you can also use "boots" to protect the terminals which should not be left exposed. You can get by with under $80 but I think most would go a size up on the battery and charger, so for most the tab would be about $120. The charger of coarse doesn't have to be carried in, only the battery, cable and converter.ducker wrote: ↑Tue Apr 03, 2018 12:36 pmThank you so much for the reply CapnLoki!!
Do you have an suggestions for a 20 AH AGM battery? (something like THIS? )
The reason I was looking at the Yeti - was that it had the window dressing (the different connections)
So if I did go with a standard AH AGM battery what assorted accessories would I need to make this work?
I'd think I would need a few different adapters/connectors for the 20 AH AGM battery, outside of the CPAP DC converter. As I'm camping in a tent, I don't really want to have to also manage a bunch of wires on top the hose of the CPAP. I just see myself getting frustrated at the whole setup.
Your comment to get the converter to save $ and lbs. How exactly? Are your tentative numbers taking the converter into account? Because I'm not excited about the idea of carrying around another 10-15lbs in a backpack for a 20 AH AGM bettery
What would you suggest for a lithium battery that would last approx 2 days? I'm expecting that the majority of use cases will be where I am camping just Friday / Saturday night.
And/or will have the opportunity to charge via a plug typically during the day. Based on your estimation, it looks like I need ~ 5 AH a night (with out heat or humidity) that battery I linked COULD do it, but I would have to charge it every day for the next time. I'd rather have a bit more flexibility in the amount of power stored in a lithium battery.
Again, thanks for your input I greatly appreciate it!
The issue with the 12/24 volt converter is that it is 90% or more efficient, while inverters tend to be 60% or worse, in spite of their advertising hype. This means that for a given load, you'll need a battery almost twice as big. My guestimate of your load is from the ResMed Battery Guide, which gives numbers for both using an inverter and using the converter, with numerous corroborations from forum members. It assumes the converter is used, but be advised that every situation is different, so every estimate should include "give or take 30%."
If you only need 2 nights with no humidity, and use the converter, you might get by with a basic Lithium pack that measures 100 watt-hours, the airline limit. The "32000" you mentioned has been claimed to run for two night so it might be worth a try. Since I've never run a cpap on lithium I have trouble doing more then passing on observations of other users, but I generally tend to go with large overkill, which is a lot easier (or at least cheaper) with AGM batteries. BTW, if you recharge during the day, you can charge 70-80% ina few hours but topping off usually takes 5 hours or more.
So I guess the issue is, how far to you have to carry in? If its 100 yards, I'd go with the AGM; if its a mile, then I'd be trying the lithium.
Yes, this might work - if anything its a bit small. First, the numbers: 24000mAh is the total of the 3.7volt lithium cells. This converts to about 89 Watt-hours, the new way to rate lithium packs. Most US airlines have a 100 Watt-hour limit, though in some cases they allow 140Watt-hours. 89wh is about the same as 7.4 amp-hours at 12 volts so this should be enough to run without humidity for a night. However, the inverter is probably about 60% efficient, so the net is around 5 amp-hours. Add to this that the airline cabin pressure it the same as an altitude of 6000-8000 feet, which the pump compensates for at the cost of more power. Also, if you use high pressure it takes more power.Cici wrote: ↑Sun Apr 08, 2018 2:50 pmI've been trying to follow along and think I may be okay, but wanted to double-check.
I will be taking a nine-hour flight soon and want to be able to use my ResMed AutoSense 10 without the humidifer during flight.
I purchased the NexGadget 24000mAh external power bank with and AC outlet. It says it can be used to power equipment within 95W.
My ResMed AC adapter says it is 90W.
Will this work for the occasional night without access to power? At $99, it was much cheaper than the $270-$450 for "cpap" battery packs out there but if it won't work, then I will bite the bullet and get one made specifically for cpaps...
Thoughts?
Thanks much,
Sorry, this is wrong- this pack is well under the airline limit. They should have included the watt-hour rating, but it works out to 89 wh,which is under the 100 wh limit.RafterDenise wrote: ↑Tue Apr 10, 2018 6:51 pmCheck with your airline, but last I heard, this is above the legal limit to take on an airplane. That said, I agree that CPAP batteries are overpriced for what they are. You're on the right track, but may need something smaller for airplane travel.
Question to CapnLoki: The Alt of the plane at 6000ft is less than sea level. However XPAP works by using the difference between outside air pressure, in this case @ 6000 ft (lower). Would not in this case make the needed treatment lower too? I would think the pressure should be a ratio that's also lower, all the XPAP pressure is there for is to keep the pipe open.CapnLoki wrote: ↑Wed Apr 11, 2018 5:14 amYes, this might work - if anything its a bit small. First, the numbers: 24000mAh is the total of the 3.7volt lithium cells. This converts to about 89 Watt-hours, the new way to rate lithium packs. Most US airlines have a 100 Watt-hour limit, though in some cases they allow 140Watt-hours. 89wh is about the same as 7.4 amp-hours at 12 volts so this should be enough to run without humidity for a night. However, the inverter is probably about 60% efficient, so the net is around 5 amp-hours. Add to this that the airline cabin pressure it the same as an altitude of 6000-8000 feet, which the pump compensates for at the cost of more power. Also, if you use high pressure it takes more power.Cici wrote: ↑Sun Apr 08, 2018 2:50 pmI've been trying to follow along and think I may be okay, but wanted to double-check.
I will be taking a nine-hour flight soon and want to be able to use my ResMed AutoSense 10 without the humidifer during flight.
I purchased the NexGadget 24000mAh external power bank with and AC outlet. It says it can be used to power equipment within 95W.
My ResMed AC adapter says it is 90W.
Will this work for the occasional night without access to power? At $99, it was much cheaper than the $270-$450 for "cpap" battery packs out there but if it won't work, then I will bite the bullet and get one made specifically for cpaps...
Thoughts?
Thanks much,
(The 90 and 95 watt ratings are meaningless here - without the humidifier/heated hose the load is around 15 watts.)
Bottom line, this will work but probably not for 9 hours- you might only get 6-7 hours. Also, don't count on gas left in the tank- you'll need a generous 5 hours or more to recharge for the return trip.
chunkyfrog wrote: ↑Thu May 03, 2018 11:03 amJust a little question: this thread (and Loki) is so brilliant that . . .
Why is it not stickied?