Camping Tech question.. from a newbie

Hello all;
After reading through the HUGE amount of posts on this subject, I still find myself needing a little clarification.

First - I understand that a deep cycle battery will power my CPAP for 'several nights' ..but if I'm going camping for a longer period (in this case, 10-14 days) am I out of luck? (I am camping away from any power source other than a jeep and don't relish the idea of running the engine for extended periods of time.

which leads to my second question, Would a small solar panel be enough to keep me going? By that I mean would it charge enough every day to do the trick?

and thirdly, as a technical rookie, is it easy to hook up my 'portable power system'?

I apologize if this has been answered before. Your help is appreciated.

Paul

If your camping in the desert and you have a way of rotating the panel with the movement of the sun ... it should work with the right set up.

If you will be near your jeep ... the deep cycle battery will be the most economical method ... get a 100 amp-hour battery or a couple of 60 to 70 amp-hours cells.

There are a few other members who can provide you the details.

Solar cell are costly, you would need a setup that would charge about 10 amp at 13 volts a day, Big $$$.$$. Charging with the jeep if you don't go anywhere takes a lot of gas, more $$$. A small generater would come in handy and use less gas, you also would need a deep cycle charger to match the battery, say 10 amp, a couple of hours a day to charge. Jim

Check the generator in the jeep for amp rating. You may not have to run the jeep very long with an high amp charger. I am planning on taking jumper cables and using someone elses vehicle for a start if I screw up with the battery discharge. My CPAP draws 3 amps at 12 volts for 8 hours, the truck should put out 35-45 amps minimum, so 0.6 to 0.8 hours for the re-charge. And a stick shift and a hill provides another way to restart if the battery is too low. A solar panel will let you run the CPAP more days before recharging, but I would not spent the money just for this application. Check your AAA coverage before you go!! LOL

A vehicle alt has plenty of power but it's controlled by the voltage regulator, even though it's rated 50 to 75 amps, that's into a load, it can only charge a battery at about 5 amps unless the battery is very low. Going down the highway the battery only charges under 5 amp after it's built up.

A battery charger, charges at 15 to 16 volts, a vehicle normally only goes to 13.4 volts (best) to 14.8 on the high end. So charging from a vehicle not going somewhere takes gas and time. Jim

Hi Paul,

It would be helpful to know what your equipment is and that would give me a better idea as to what its amp draw would be.

Do you sleep 7, 8, 10 hours a night?

My Remstar Pro2 draws about 1.2 amps/hour at a constant pressure of 11 cm H2O. My newer "travel" CPAP a Puritan Bennett GoodKnight 420G draws closer to .6 amps/hour at the same pressure. So pressure and machine are two important variables.

A battery isn't like a wall outlet. A 12 volt battery has a voltage of about 12.84 volts when fully charged (100% state of charge (SOC)). That drops to 12.5 at 75% SOC, 12.2 at 50% SOC, and 12 volts at about 25% SOC. My Remstar machine won't run at less than 12 volts so I only get 3/4 of the battery's "rated" full capacity.

I'm inclined to think a portable generator would be your best bet for an extended trip of 10-14 days.

Having said that, there are two battery/charging solutions that you might consider. You could jumper it to your Jeep's charging system but car alternators generally only put out a fraction of their rated output when idling. So you'd need to rev the engine to get the fastest charging performance. If you pursue this I strongly recommend that you get real cables, not jumper cables, because it's going to take some time and jumper cables were never intended as a prolonged power connection. Alternately, you could rig your Jeep for charging the deep cycle battery in an auxiliary battery configuration the way RVers do and the way I did for my motorcycle camping adventures. You'd drive around for a while, go to town, see some sights, etc. And the battery would charge very efficiently. This last strategy requires a voltage sensitive relay, a secure mounting for the battery, and some wiring/connections. The project isn't terribly complicated but you should have some experience with wiring stuff.

I certainly wouldn't go out with a solar panel and the "hope" that all works out. There are a lot of factors, like DreamStalker said about tracking the sun and many solar cells products promise performance that is measured in ideal settings. Perhaps spending some of the trip without the CPAP isn't a big deal but it would be for me.

You can read about the battery system I built for my motorcycle. The post (link below) has lots of good info from my own research that started about a year ago. http://www.sport-touring.net/forums/ind ... 273.0.html

Give me a little feedback and I'll try to steer you towards a good solution.

Cale

I use two Optima deep cycle marine batteries-- a blue-top 55 AH and a red-top 56 AH --that together give me 40 hours @ 12cm H20 with passive humidifier. At home I use 14cm, but 12cm saves considerable battery power over several nights and I discovered that when I'm outdoors I awake fully refreshed after six or seven hours at 12cm.

I must emphasize here that I recommend using very good quality cables and achieve good power connectivity when mucking around with DC power to AC devices. Fused cables (the kind your machine manufacturer or knowledgeable DME will recommend) are best. These are easy to hook up. Simply attach the red and black DC power cables to their corresponding battery posts, plug the appliance-end of the DC cable into your machine's DC power input (another great reason to buy this piece direct from the manufacturer--to GET THE RIGHT PLUG-IN -- and turn on your machine as usual. If your results are like mine, you will notice more pressure using DC than you achieved at home running direct-AC.

I paid just $20 for my well-used red top, which gives close to 27 hours of good pressure. I bought the blue-top new for $160, but it only gives me 13 hours 45 minutes before the juice runs out. These batteries weigh a ton, so they are obviously just for base-camp situations. I picked up the great used one at a distributor I found via the Interstate Battery online dealer locator, and will never buy another new one. The best thing about the Optima batteries is they are gel cells, which can be mounted any-which-way (including upside-down if necessary), and can stand quite a bit of tumbling around, never leak, and are maintenance-free.

There was only one time that I had a problem finding power to charge while camping for an extended period (the charger rolls with me too, of course). Six of us were in the middle of nowhere and I didn’t have access to a vehicle the day my juice ran out to search for a power outlet. Shortly after everyone hit the sack that night, the first of many of what would later be coined "Sasquatch death screams" started coming from my bedroll. Long story short: both of my batteries were fully charged before dinner, and I didn’t have to lift a finger.

Happy trails!

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CPAPopedia Keywords Contained In This Post (Click For Definition): humidifier, DME, Power

flindar wrote:First - I understand that a deep cycle battery will power my CPAP for 'several nights' ..but if I'm going camping for a longer period (in this case, 10-14 days) am I out of luck?

If you can't charge the battery, its unlikely to last you 10-14 days with any real world CPAP set up.

which leads to my second question, Would a small solar panel be enough to keep me going? By that I mean would it charge enough every day to do the trick?

It depends what you mean by "small"!

The Solarex (BP Solar) BP380 Polycrystalline solar panel array measures approx 537mm x 1204mm x 44mm and weighs in at 7.5 Kg. It can deliver 17.6 Volts at 4.55 Amps (~80 Watt) which would a put a good charge into a 12V battery on a daily basis. This array is fairly rugged too.

Click on this link for detail on the BP380. They cost the equivalent of around US$700 here in Australia.

There are a few other commercial solar panel arrays in this class as well. Some go to higher power levels (~120W) but with increased size and weight.

As an alternative to solar charging, you might want to consider a small petrol generator, such as a Honda EU 10i or EU 20i (I think tthey have different model numbers in the US, maybe something like EU 1000i & EU 2000i).

and thirdly, as a technical rookie, is it easy to hook up my 'portable power system'?

If you are not familier with electrical circuits, it probably a good idea to get someone who can help you get it initially set up and wired to a "plug and play" state. After that it should be simple to use.

Cheers,

Bill

NomoreCrashcart wrote:I picked up the great used one at a distributor I found via the Interstate Battery online dealer locator, and will never buy another new one.

I doubt the fact that the new battery under performs the used one has anything to do with it being new. More likely it was damaged sometime early on and has never held a full charge since. I get well over 16 hours without drawing 1/2 the power (PB 420G 11 cm) from my Odyssey PC680 (17 ah). That's from a battery that's a third the size of your blue top.

It must be frustrating to have gotten such bad performance from the new battery.But because batteries have a limited number of charge/discharge cycles, I recommend people buy new batteries, charge and maintain them properly, and use them right away.

Of course, for $20 that Red Top was a steal of a deal. Congrats!

Cale

From reading all this, one would think you need one of these:


and depending if camping means NOT running the Jeep for days on end. I know if I went camping with a jeep it would be driven during the day.

If you took an extra battery along and connected it via cigarette lighter cord it would recharge as you are driving around, you would NEED some way of strapping the battery down in the Jeep so it doesn't go flying around (I suggest getting a plastic Marine battery container from Wal-Mart for about $10 bucks putting the battery inside it, and it comes with a strap to tie it down in the jeep.

If you drove around for 1 hr that battery would be fully recharged.

They also have this for about $50 bucks, you can use it during the night and recharge during the day. One of those solar panels would also recharge, I have one that came with my VW and it works pretty good.

I got so LUCKY this weekend. I went camping in Manistee, MI. at a camping event. I got my camp all set up in a nice quiet area of camp. went down to see a friend of mine, and the camp has installed electricity since last year. lol I've never seen such a thing!! So we walked down and carried my tent back, I was able to sleep peacefully all nite. I got picked on though for us carrying the tent back they were calling it a mobile home lol hey it worked for me.

sleepinginseattle wrote: I'm inclined to think a portable generator would be your best bet for an extended trip of 10-14 days.

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CPAPopedia Keywords Contained In This Post (Click For Definition): 420G, Puritan Bennett, CPAP, Power

Is there a portable generator that's quiet enough for nighttime use with a CPAP? If you go the generator route, would it be important to use a power conditioner so your xPAP doesn't get fried?

Regarding battery maintenance: what's the best way to keep batteries charging and chargeable, and how often do you have to check the charge on deep cycle batteries to make sure they're always ready? Is it wise to completely discharge them and re-charge every couple of months, as I do? Or is that old-thinking from nickel-cadmium 'memory effect?'

THIS IS A GREAT THREAD, thanks!

flindar (and quite a few others posting in this thread) have already waded through other discussion topics about camping and battery operation of cpaps. It's always a good subject to bring up, as there are always new readers who want to know what might work for them.

I've added this great thread to the many here:

LINKS to Battery operation, camping, power outage
viewtopic.php?t=9682

Snoredog wrote:If you took an extra battery along and connected it via cigarette lighter cord it would recharge as you are driving around, you would NEED some way of strapping the battery down in the Jeep so it doesn't go flying around (I suggest getting a plastic Marine battery container from Wal-Mart for about $10 bucks putting the battery inside it, and it comes with a strap to tie it down in the jeep.

If you drove around for 1 hr that battery would be fully recharged.

10 amp power outlet + 2 amp cigarette lighter cord + discharged deep cycle battery =

It may not be as complicated as this ...


But it's at least as complicated as this ...


I can think of ways to minimize the task of driving around. But your suggestion would entail driving 6-1/2 hours EVERY day to restore each 10 amps of current spent powering the CPAP at night. This assumes you do it right and use an inverter at the power outlet and plug in one of these

a 1.25 amp motorcycle battery charger. Don't even think of using a bigger battery charger with your inverter. The cars "cigarette" lighter circuitry was never designed for the loads these devices require.

They also have this for about $50 bucks, you can use it during the night and recharge during the day.

This is an unrated 5 lb unit that is designed to restore enough of a car battery to give it a start. Maybe just a single try at a start. It is not designed to provide 12 volts of power continuously and would be a poor choice for powering a CPAP. I doubt it would power a CPAP more than a couple hours.

The little solar panels won't recharge the 6-10amps in less than 20 hours. Useless, IMO, for recharging a deep cycle battery. A larger panel, like the one Bill described look relatively inexpensive (around $500, if you can find one) until you realize that this is for an unframed panel without connectors and to get the framed panel it's going to run around $1,000. Pray for sun light, hope all your connections are made, and that the panel didn't get damaged while you carted it (17lbs) on your camping adventures.

Powering a CPAP for 10-14 days without access to a 120 volt ac outlet is a challenge! That's why I think the easiest solution would be a portable gas powered generator. Gas generator - check. Gas - check. CPAP - check. You're good to go.

NomoreCrashcart wrote: Is there a portable generator that's quiet enough for nighttime use with a CPAP? If you go the generator route, would it be important to use a power conditioner so your xPAP doesn't get fried?

I looked into portable generators about a year ago and Honda makes an excellent small generator (EU1000i) that produces about 59 decibels at 23 feet. For reference: 50 decibels (normal indoor conversation), 55 decibels (passenger car idling), 60 decibels (passenger car moving slowly). With the generator placed at the end of a 25 foot extension cord, I could sleep with that amount of noise. It would be a "white" noise and I tolerate that well. But everyone would hear that noise and many campgrounds have quiet hours between 10pm and 6-7am, so it could be a problem.

You wouldn't need a power conditioner with the Honda unit because the power is so clean. Other generators might be equally clean but that would have to be researched.

The Honda generators are rather expensive (around $700) and when I looked at them, my thoughts quickly turned to how I could use it when I wasn't camping. That started me thinking about a power outage at home and how the 900w EU1000i wouldn't be big enough to run the refrigerator and some lights and the TV... Soon I was thinking about larger generators. That really put me off the whole idea.

Regarding battery maintenance: what's the best way to keep batteries charging and chargeable, and how often do you have to check the charge on deep cycle batteries to make sure they're always ready? Is it wise to completely discharge them and re-charge every couple of months, as I do? Or is that old-thinking from nickel-cadmium 'memory effect?'

The best way to keep a lead acid deep cycle battery fresh is to charge it properly and then keep it on a trickle charger like the Battery Tender Plus (see picture in previous post). You can check a battery's state of charge with an inexpensive multimeter. Leave the battery off the charger for 5 hours and measure at the terminals. Anything above 12.7 volts should be considered fully charged.

All batteries wear out. A battery may be rated for a number of discharge/charge cycles before it loses its ability to hold a full charge. That rating depends on a lot of variables. How deep was the discharge? What level of charge is considered fully charged? It's not really worth worrying about for xPAP users. Worth considering is how much power your particular xPAP draws (measured in amps per hour) and how long you will need to use the battery before recharging. Your calculations should allow for a battery rated so that no more than 2/3 its capacity is used. (If you want a quality deep cycle battery to last a long time.)

If you discharge monthly, try to avoid going below a 50% state of charge (about 12.2 volts). This applies to deep cycle batteries. Automotive starter batteries aren't designed for deep discharge and will be intolerant to use as a xPAP power source.

Good luck and use your battery because if you don't it probably won't work as well when you need it.