CPAP battery pack vs battery

Discussion in 'Camping for the Medically/Physically Challenged' started by gnies, Jun 8, 2013.

  1. rabird

    rabird Howdy!

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    Laniest

    Avoid batteries with 'DP', while they may be okaye for cycle service, a similar sized 'DC' would be better. DP batteries should only be discharged 30% or so for long life, DC up to 50%. Both require prompt recharging and care.

    compare the DPs to DC batteries, 20 hr rate.
    http://www.dekabatteries.com/assets/base/0194.pdf

    '1. As noted in the above graph an adequete initial AH cushion must be designed into your deep cycle system to allow for maximum cycle life. This cushion takes into account natural battery degradation as well as degradation due to battery cycling. The graph indicates that a 35% Depth of Discharge (DOD) cycle would yield approximately 2.5 times the cycle life of a 95% DOD cycle. Normally planning for an initial DOD of 30 - 50% will yield the maximum battery cycle life. Too high of initial DOD cycle will result in the battery not providing the necessary power requirements over a longer time period of approximately 3-4 years. Higher DOD cycling will also increase the cycling degradation of the deep cycle battery and shift the above curve to the left. (If the deep cycle marine battery is a "main" battery and will be also used be used for engine starting the initial DOD should not exceed 20-30%.) '

    From ah planning tab or page 19
    https://drive.google.com/file/d/0B-r-cHocscVWLWp2NHBjcXlxN3M/edit?usp=sharing
     
  2. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    Yes. That's what I do. My wife uses a CPAP and we run it and meet the trailer's electrical needs on two Group 27s. But batteries wired in parallel must be of similar size, age and condition. It's best to buy two new ones at the same time.

    In the past we could usually go three days before needing to recharge, although if it got cold at at night the furnace ran more and our battery time dropped to two days. We recharged with a smart, three-stage charger plugged into a Yamaha 1,000-watt generator. Now we have a solar charging system which is on all day, every day. Each day that makes up most or all of the power we used the day before unless it is cloudy. I still carry the charger and generator for the times when the solar rig can't do the job because of weather.
     
  3. speckhunter80

    speckhunter80 Well-Known Member

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    Assuming you sleep/use your CPAP for 8 hrs. a night and you camp two nights, then that would be 90 amp hours plus the lights. To be on the safe side lets say you need 110 amps for a two day trip, there fore you need 220 or more amps of storage without having to recharge. That would be equivalent to two 12V group 31 batteries or two 6V T-105 batteries. You could also go with two group 27s 12Vbatteries and an 80-100 watt solar system which would recharge 28-35 amps per day. This would allow you to stretch out to 3-4 nights, weather dependent.
     
  4. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    I should mention that most of our local trips are 4-5 days and our touring trips are 1-2 months. This obviously requires a different "power strategy" than a two or three night weekend trip.
     
  5. SidecarMike

    SidecarMike Active Member

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    Reading all these posts caused me to question my unit. It is an auto titrating BiPAP. Unlike the CPAP, on mine the pressure goes way down when I exhale, then up when I inhale. In addition, the auto titrating part means that it is set with a low of 4 cm h2o and 20 cm h20. It only feeds as much air as is needed. If I breath normally, the pressure is very low, but if I don't respond by exhaling, it rises to open my throat.
    The reason I mention all of this is that if I hook up an amp meter to mine; one of those things that plugs in the wall and you plug an appliance into it, my draw ranges from .2 to 5 amp.
    My motorcycle battery, Xtreme Permaseal AGM Battery XTAX24HL-BS, always makes it through at least two days and sometimes a third without a recharge. I can't find an amp rating except 350 CCA on it.
     
  6. PopUpSteve

    PopUpSteve Administrator

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    Just throughing this out there but I have found I sleep better when camping without using my CPAP then with. Must be all that fresh country air.
     
  7. SidecarMike

    SidecarMike Active Member

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    But is that true of your fellow campers? I have a friend who says the same. Unfortunately his snoring, choking, and gasping for air tend to keep all his neighboring campers awake.
     
  8. rabird

    rabird Howdy!

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    Would those amps be at 120v?
     
  9. SidecarMike

    SidecarMike Active Member

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    Yes, it is. My point was that it isn't pulling full amperage at all times. I'm sure that's true whether on 12 volt or 120. I don't know if that holds true for a CPAP. I never had one of them.
     
  10. jbirdt2001@yahoo.com

    jbirdt2001@yahoo.com Active Member

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    eyeinthesky says
    I use a portable battery when we are on motorcycle tent camping trips also when we are pup camping where there is no power.
     
  11. 88PUP

    88PUP being crazy- has kept me from going insane

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    HA!!!! LMAO at myself [LOL] [LOL] I looked at the thread title and thought it said "CRAP battery pack vs battery". I thought it was a new fossil fuel development!!!
    Too bad....I would never have to buy another battery!!
     
  12. Axel

    Axel Member

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    Most solutions in this thread (and others) seem to target 2-3 days at most. Does anyone have a longer term strategy? I have several 8 night trips planned for 2014, all dry camping. CPAP without humidifier needs about 1amp/hr, figure 10amps a night including margin (ResMed S9).

    The Group 24 on the trailer won't cut it, and I don't think I can add another exterior house battery due to both tongue space and hitch weight concerns. So the "buy two T-105's" solution isn't going to work. A generator is something I'd prefer to avoid.

    I'll buy a solar system (120w solar blvd most likely), but in campsites like this: http://goo.gl/maps/Y8aQa its not going to produce much, if any, power unless I can move the battery and panels to the sunshine.

    With an enclosed TV I'm not hauling extra wet batteries, so carrying more batteries or an interior battery bank means AGM. The idea of swapping batteries on the tongue with the bunks out seems like no fun, and possibly a recipe for an accidental short.

    What I think I really want is a "portable" power pack with a _large_ AGM I can dedicate to the CPAP. However this seems to be limited to the very expensive Goal Zero Yeti, or the new ArkPak (https://www.arkportablepower.com). I suppose I could build my own for less than the ArkPak, but I'd want the metering and several chargers (AC->DC, car DC->DC) so I'm not sure it would be a large savings.

    Is there some option I've missed? I'll do what it takes, but these all seem like poor choices. I'm amazed that there aren't more power packs with 100 Ah capacities.

    Axel
     
  13. Unstable_Tripod

    Unstable_Tripod Well, there's your problem!

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    If you use a CPAP, are going out for eight nights without hookups, have one Group 24 battery and will be in a place where you can't recover the previous day's power consumption with solar, you really have no choice but to use a generator. Get a smart, three-stage charger and a small generator to run it. My 1,000-watt Yamaha is super quiet and works very well for this purpose. When I need to do this I do it mid-day and it takes a few hours.

    IMO, the charger and the generator are much better uses of your money than the power pack because they are more versatile. You can, for example, use the charger to maintain your battery between trips and in the off-season. My charger even has a car start option so if necessary, I could start the truck with the genny and charger. That sure beats hiking for miles or waiting hours for AAA to show up if I get in a pinch.

    BTW, I've been to Jedediah Smith and the Redwood National Park several times. Fantastic places! They shot the forest battle scene of the third (original) Star Wars movie in the Redwood grove across the river from the Jedediah Smith CG.
     
  14. bildoo

    bildoo New Member

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    I don't know about anywhere else. At WI state parks the host sites have power and the hosts are happy to lend an outlet to plug your charger and battery in. The last time I camped the host even had 3 of his own chargers people could use.
     
  15. Axel

    Axel Member

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    Unstable_Tripod, the Redwoods NP/SP are great. We stayed at Prairie Creek last year with a rented Fleetwood Santa Fe that sold us on buying a popup. We went to Smith on a day trip and decided it would be our one repeat park for this year.

    I know the generator is probably the most versatile, but it's the dead last option. Both my personal preference and spousal acceptance. Neither of us like listening to other site's generators (even the Hondas) thrumming away, and we don't want to add to the noise. We also don't like the idea of scheduling our day around generator hours every other day to keep the G24 charged, so we'll need more battery capacity anyway. Finally, and somewhat irrationally, I don't like the idea of something that valuable and portable that is constantly announcing its presence.

    bildoo, I hope to find a kind ranger or host, but I want to come prepared for the worst. We will be going to at least two new parks a year, and I don't want to assume there will always be an outlet offered.


    So start with the assumption that I have a generator-sized budget to spend any other way. The Goal Zero fits the budget (almost) but has only 100 Ah so I'll be cycling it very deep. The ArkPak will take a Group 31 so a 130Ah would cover me, but its pricey for what you get and not very flexible (i.e. I can't trade CPAP power for house power if I want to run the furnace).

    The other possible option is to build an interior AGM battery bank. That's the most flexible for usage, but the least portable, can't move it to sunshine very easily.

    I keep hoping for a better suggestion. Some sort of outboard battery bank for the trailer?
     
  16. EvilUncleEarnie

    EvilUncleEarnie New Member

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    I just came back from camping for 4 days in Utah. I have to use a CPap or neither the boss or I get any sleep. I bought a battery and an inverter and also a car charger cord. According to the description, the battery is supposed to go for 2 or 3 days but I found that at best all I can get is 1 and a half days out of it. And it will do the heater but it discharges the battery and you will probably not get even one night out of it. I was going to borrow my brothers portable generator but instead since he had a generator in his RV I just plugged it into the wall socket and charged it. It took a couple of hours to charge it.

    I had no problems sleeping and actually slept better than I do at home.

    http://www.cpap.com/productpage/respironics-battery-pack.html?gclid=Cj0KEQjwk7msBRCJj67khY2z_NIBEiQAPTFjv5oso5rbTwEqJfiPQowlXEWe71amZk0Aiyc5u6L0UY8aAqJd8P8HAQ

    http://www.cpap.com/productpage/respironics-12volt-dc-power-cord.html

    http://www.cpap.com/productpage/150w-inverter-c-100-battery.html
    Modify message
     
  17. crackerJack

    crackerJack Well-Known Member

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    Going without my cpap is not an option. I used a diehard portable power jump start battery when tent camping. Using dc cig plug I could get 3 nights. Using built in inverter ac plug 1 1/2 nights. I now have 2 6v xc2000 on my camper. With my camper batteries and portable power battery, I assume I can go for 8 nights.
     
  18. Axel

    Axel Member

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    I never really followed up on this thread, and I really should write up a separate post with the results of my experience and research.
    In the meantime, see my comments in this thread:

    http://www.popupportal.com/index.php?topic=85950.msg849472#msg849472

    In short, I have a solar panel, but rarely use it. No generator.

    I ended up with the ArkPak and a 100amp hour group 31 AGM. As it turns out, this was overkill. I just finished 10 nights of CPAP usage in Yellowstone/Teton and left with a 50% charge. Since I have no serious concerns about shorter lifetime from deeper discharges (see http://www.popupportal.com/index.php?topic=86380), I expect I could have gone another week without recharging at all.

    In hindsight my only real regret is that the ArkPak is quite expensive for what it offers and the bulk of the value is in the AGM battery itself. If I had to do it over again I probably would build a custom solution from a separate sturdy battery box and external charger. There are several suggested designs on various CPAP user forums.
     

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