Apnea Board Forum - CPAP | Sleep Apnea
Camping with a CPAP or surviving a power outage - Printable Version

+- Apnea Board Forum - CPAP | Sleep Apnea (https://www.apneaboard.com/forums)
+-- Forum: Public Area (https://www.apneaboard.com/forums/Forum-Public-Area)
+--- Forum: Main Apnea Board Forum (https://www.apneaboard.com/forums/Forum-Main-Apnea-Board-Forum)
+--- Thread: Camping with a CPAP or surviving a power outage (/Thread-Camping-with-a-CPAP-or-surviving-a-power-outage)

Pages: 1 2


Camping with a CPAP or surviving a power outage - Many Klatch - 06-25-2012

I got my CPAP in 2007. It is a wonderful device and solved a lot of sleep related health problems. However, I do a lot of primitive camping and often there is no electric socket within miles of my camp. So I had to do some investigating on how to have my CPAP and camp too.

My CPAP is a Respironics ReMstar Plus. I found that the RemStar Plus is a 12 volt machine and that Respironics makes a hookup that looks like jumper cables that directly hook up to a standard 12 volt battery. I also found that the RemStar Plus air pump is detachable from the base unit and it makes a fairly compact unit when used seperately.

My buddy Rick who also camps with a CPAP directed me to WalMart to get the biggest deep well trolling motor that they had. We determined that most CPAPs draw about one amp per hour if not being used with the humidifier. Some of these batteries are rated for up to 930 CCA cold cranking amps so you should be able to get several nights sleep out of one batter. I just recently got 9 days of CPAP use out of a battery before it started to slow down the CPAP.

By the way. If you want your big batteries to last you need to recharge them slowly at 2 amps per hour. I usually get 3 or more years out of my batteries while Rick who was recharging at the maximum rate was only getting 6 months to a year.

If you use the humidifier they draw a lot of power and you will not get as many nights sleep, possibly as few as one or two nights. I found that since I camp mostly in the Midwest that a humidifier isn't a problem in the Summer with the usual amounts of high humidity.

Rick has a CPAP that runs off of standard house current so he has to use a battery power inverter. He got annoyed at the noise the inverter made. With a little bit of study he found that the noise was from the inverter cooling fan. Most inverters are rated for enough amps to run a toaster or a refrigerator. A CPAP without the humidifier only draws one amp so the inverter never gets hot. So he took his inverter apart, found one of the lead wires to the fan and cut it. Now the only noise from Rick's camp is the CPAP, not the much noisier inverter.

Finally, I am getting ready to experiment with a motorcycle battery for weekend events or for a backup at weeklong events. I have been carrying two deepwell batteries with me and if I can do without an extra 40 pounds of lead battery that would be a good thing.

In the 5 years that I have had the CPAP we have had a few short power outages at home. They don't bother me I just grab one of the batteries, hook it up and go back to sleep knowing that even if the power is out for a couple of days that at least I will get a good nights sleep.Sleep-well

AB








RE: Camping with a CPAP or surviving a power outage - Dreamcatcher - 06-25-2012

Hi Many Klatch just wanted to welcome you to the forum Big Grin

Welcome


RE: Camping with a CPAP or surviving a power outage - SuperSleeper - 06-25-2012

Howdy, Many Klatch, welcome to Apnea Board!

(06-25-2012, 08:03 AM)Many Klatch Wrote: Some of these batteries are rated for up to 930 CCA cold cranking amps so you should be able to get several nights sleep out of one batter. I just recently got 9 days of CPAP use out of a battery before it started to slow down the CPAP.

Just to help you a bit here, CCA (or cold cranking amps) has nothing to do with the capacity of the battery to run things for long periods of time. CCA rating is defined as the current a lead-acid battery at 32 degrees F can deliver for 30 seconds. CCA is for judging how well a 12-volt battery will start an automobile engine using short current draws typically used in starting an engine (that last for less than 30 seconds).

The correct rating to look for on a 12-volt deep cycle or "marine" battery is the Amp-hour rating. The higher the amp-hour rating, the better the battery will be for powering things like CPAP machines for long periods of time. If the battery has no amp-hour rating, it should not be used for extended CPAP use. Good quality true deep cycle batteries will have this amp-hour rating printed on the battery label somewhere. One typical Wal-Mart deep cycle marine battery I purchased last year for around $70 was rated at 110 amp-hours - it is about the size of a standard car battery. These types are really not true deep cycles, but they are hybrids - a cross between an automotive battery and true deep cycle battery. It's all about how much lead is inside the battery itself - generally, the more lead, the heavier the battery and the more robust it's going to be for current draws over long periods of time (like CPAP machines).

If you are using a deep cycle or marine battery so long (9 days) that it actually discharges enough to "slow down" your CPAP [with a 1 amp draw], you are discharging the battery way too much. Allowing a deep cycle lead-acid battery to get that low will damage the battery's capacity and if you do this too many times, you'll end up with a dead brick instead of a battery.

For best battery life, you generally don't want to allow your 12-volt lead-acid battery to get below a 70% charge... and keeping it above 80% will extend the battery life further.

You can do a basic test of battery charge by letting the battery sit with nothing attached to it for at least 2 hours, then do an "open terminal" test using a voltmeter across the positive and negative terminals. It's not a completely accurate way to determine a battery's charge, but here's the basics:

[Image: attachment.php?aid=220]



RE: Camping with a CPAP or surviving a power outage - PaulaO2 - 06-25-2012

Not to argue with you, SS (well, okay, maybe a little) but sometimes it is good to drain a battery down. As I understand it, batteries have a kind of 'memory'. If you regularly keep a battery charged, it will slowly loose more and more of its abilities because it only goes so far due to its 'memory' of where it should be. Draining it all the way down allows that memory to be reset. With my chair batteries, I was told to let the batteries drain all the way once a month then charge them. If I was to do a big thing all day, I was to charge them, wait an hour, then charge again. The batteries on my chair are 5 years old and only recently started losing their charge. I was surprised that I was able to go all day in Minneapolis last week. It had difficult using the tilt but still kept going.

I also learned the same thing when I was talking to others about off-the-grid ham radio operation. So while it may be a Southern myth, I tend to believe it works.

However, regularly draining a battery is not good either. I was not as gentle with my first chair and in the five years of its life, I went through three sets of batteries.


RE: Camping with a CPAP or surviving a power outage - SuperSleeper - 06-25-2012

Paula,

Not sure what type of batteries your chair batteries use. But if they are lead-acid deep cycle batteries, it is commonly agreed upon that the "memory effect" on these types of batteries is a myth.

Just Google "battery memory effect lead acid" and you'll see the vast majority of reputable sites say lead-acid batteries don't have memory effect. I got into this with my solar panels also, and those folks live and breathe deep cycle lead-acid batteries day and night... and all the ones I've talked to never completely discharge their lead-acid batteries.

Just as a challenge, can you find some reputable websites that say lead-acid deep cycle batteries suffer from memory effect?

Now, that said, there is a difference between doing a deep-discharge of lead-acid batteries and doing a complete discharge. The batteries are designed to be deeply discharged, but not completely discharged.

NiCad batteries, and to a lesser extent NIMH do suffer from memory effect, however, and completely discharging those types of batteries is common practice.

There's a lot of misinformed battery sellers out there... telling someone to completely discharge a lead-acid deep cycle battery will lead to early battery failure.

Either your battery person doesn't have a clue or your chair batteries are not lead-acid deep cycles, I think.










RE: Camping with a CPAP or surviving a power outage - Sleepster - 06-25-2012

(06-25-2012, 11:32 AM)PaulaO2 Wrote: Not to argue with you, SS (well, okay, maybe a little) but sometimes it is good to drain a battery down.

This is true of the nickel batteries (NiMH and NiCd). It's not true of the lead-acid batteries or the lithium-ion batteries. It is true, though, that you can reset a faulty battery meter on a lithium-ion battery by discharging and recharging (deep cycle).


RE: Camping with a CPAP or surviving a power outage - Sleepster - 06-25-2012

(06-25-2012, 08:03 AM)Many Klatch Wrote: Finally, I am getting ready to experiment with a motorcycle battery for weekend events or for a backup at weeklong events. I have been carrying two deepwell batteries with me and if I can do without an extra 40 pounds of lead battery that would be a good thing.

You might want to get a solar charger. They're light weight and will allow you to recharge that smaller battery, getting more use out of it.


RE: Camping with a CPAP or surviving a power outage - PaulaO2 - 06-25-2012

Yes, they are sealed AGM, Group 34. HUGE heavy monsters.

No, I'd never completely kill a battery. I let it go until the red light on the indicator is on (it goes from a green to an orange to a red) once a month or so. Three times I've let it go (accidentally) to where the last red light is blinking and I practically had to be pushed to the truck.

I'm due to get another chair so when I go talk to the folks, I'll ask them about the battery charging suggestions.

I'm disappointed I was wrong. I so wanted to correct you. Dangit.


RE: Camping with a CPAP or surviving a power outage - PaulaO2 - 06-25-2012

Many - There's a website called WindSun that sells solar panels, chargers, batteries, etc. They also have a huge FAQ section.

And yes, I was wrong. Lead acid batteries do not have a memory. They say to never completely drain one. Dangit.


RE: Camping with a CPAP or surviving a power outage - SuperSleeper - 06-25-2012

(06-25-2012, 12:39 PM)PaulaO2 Wrote: I'm disappointed I was wrong. I so wanted to correct you. Dangit.

Oh, don't worry... I've been completely full of baloney on several other subjects... just do a forum search for my posts and I'm sure you'll have plenty of opportunities to correct me. Too-funny

But, being full of baloney hasn't stopped me from posting... yet. Coffee