How can I run a CPAP in my tiny van?

[BigT]

 Not sure what "N-Type" means.  

Answer:  "The majority of commercial solar cells today are manufactured from the boron-doped p-type silicon.  However, due to its high tolerance to most metal impurities, the quality of phosphorus-doped n-type silicon material is significantly better than comparable p-type silicon."

Thoughts??   :huh:

 

[offroad]

P is positive electro chemical material. N is negative electro chemical material. When you make a transistor it is either a NPN or a PNP transistor. The chemicals allow flow of electricity in a controlled movement. Think of n or p as a gateway for electrons. Depending on which direction they need to go. The chemicals are some mixture of silicon with impurities.

 

[BigT]

Thanks, offroad! Can I run either design (N or P) with the same charge controller and wire them the same way, or does each require something special?

 

[BigT]

My single 100w panel gives me more power than I could use with my CPAP, cooker, water heating device fan, computer, cell and lights.  If I upgraded with more panels I could put in a freezer.   

Are you charging solely off of the panel, or do you have some sort of back-up, like the alternator?  
(forgive me if you answered this question someplace else).

 

[GotSmart]

Are you charging solely off of the panel, or do you have some sort of back-up, like the alternator?  
(forgive me if you answered this question someplace else).

I have the capability to use the alternator.  (130 W)   That was my only source for charging the batteries before I got the panel.  As it is, the indicator shows full charge before mid day. Like I said, with 200W in panels I can put in a freezer.  I will most likely buy a single 250W for my next build.  I need a larger van.  The shorty is not quite what I need.  

Build yourself what you think will work.  Next year, try something else once you see wht you have does, and how it meets your needs.  That is the beauty of working on something you own.  There are always people that want what we are creating, so it is always a decent investment.  Never a complete loss like many improvements in a sticks and bricks.    Solar will always pay off.  Even if it not quite what you need.

 

[offroad]

Thanks, offroad! Can I run either design (N or P) with the same charge controller and wire them the same way, or does each require something special?

Virtual direction of electron flow is very defendant on design. No you can not wire them the same way. If you put them the wrong way, best case they do not work. Worst case they thermal overload and burn up or explode.

 

[BigT]

Build yourself what you think will work.  Next year, try something else once you see wht you have does, and how it meets your needs.  That is the beauty of working on something you own. 

The truth is, the ONLY reason I'm considering solar is because I've been diagnosed with sleep apnea and I need a way of running my CPAP machine in the van.  
If that hadn't happened, I wouldn't be doing this at all!  
My original plan was to use the van simply as a rolling, metal tent.  I was perfectly happy using an ice chest, camp stove, LED lights and other rechargeable devices when camping.  I never had any intention of installing a fridge, microwave, coffee maker, or electric heater.  

I'm finding this entire process to be extremely frustrating.    If I keep this up, Bob is going to ban me for being an annoying and indecisive PITA. 

SternWake suggested that I might be able to mount a Northstar AGM under my hood in place of my OEM battery (in addition to my 190W panel), and I haven't been able to stop thinking about that option.  It's just sounds so easy, convenient and space-saving.  If I could make that system work I would be thrilled beyond words!  (of course it might not fit).  

It should be noted that I am not full-timing and likely won't be for many years to come.  I only use the van on weekends, sometimes, to get away for a day or two at most.  

I need to sleep.  I'm starting to spin out of control.

 

[akrvbob]

I'm not even considering banning you, but I am giving serious thought to sending the guys in the white coats and that weird jacket to visit you!!
Bob

 

[SternWake]

Only a weekend here and there??!!!!!!!

My recommendations have been based around full timing and maximum battery longevity for a system about to be put into use.

A weekend here and there!!!!!?????????

Bob, send the guys in white lab coats with funny jackets for me instead.

Locusts, kayaks, alternators!!!!


Arggghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

lock me up

 

[BigT]

Well I like the idea of full timing, but if that happens it's going to be a while until it does.  Still I thought it would be a good idea to plan for it now, and maybe even just build it for that purpose now while I have a place to do the work.  
I have a 17+ year old cat who simply won't go anywhere near a car without peeing all over the inside, so full timing has to wait.  

I just got her back from the vet yesterday, and they gave her an astonishingly clean bill of health.  Said they couldn't find anything wrong with her at all.     So it looks like she's going to be around for while.  

SW.  I assure you I was not wasting your time when I asked my questions.  I'm simply getting frustrated with the complications and want this project to be over with as simply and quickly as possible, so I'm willing to modify my intended uses of the system if that makes things go smoother.  
Right now I'm stuck on CC's and I fear the solar dealer I'm working with has no idea what I need and is simply a salesman, looking to make a sale.  

I'm building a cardboard mockup of the Group 24 NS AGM to see if I can cram it under the hood.  Measurements are nice, but having a box that perfectly duplicates the battery's size leaves no room for doubt.     
The NS 24L is the only AGM of that capacity I've found with that small of a case.  I realize it's not a 27, but that simply won't fit.

Your advise, and that of others, has been greatly appreciated and super helpful. in my own defense, when I wrote that earlier reply I was suffering from extreme stress and exhaustion from not getting enough sleep this week.

 

[offroad]

Don't know why this is hard. I use a CPAP. It works off an old used car battery, with a 100 watt inverter. Just charge the battery with solar or via engine. It just works. --- but my CPAP is five years old so it's pretty modern low power.

 

[Optimistic Paranoid]

I had one cat live to be 22, so you may be stuck there for some time yet!

Knowledge is always useful and worthwhile, so just don't forget anything we've been trying to pound into your thick skull!  

Regards
John

 

[GotSmart]

Just go with a firefly.  No fuss, no extra work.  Plug and play system.

http://www.renogy-store.com/Portable-Solar-s/1876.htm

 

[BigT]

I had one cat live to be 22, so you may be stuck there for some time yet!

A friend told me her cat made it to 21.  I think I'll be paying rent on an apartment for a long time to come.  

Thanks OffRoad.  I'm going to see if I can squeeze a Group 24 AGM under the hood.  If I can, hopefully the 190 Watt panel will be enough to supplement the charging on my mostly 2 day camping trips.

 

[gcal]

At the risk of sounding judgemental, there are physical contributers to sleep apnea that I would address before I would let it interfer with my lifestyle. Drop a few pounds. Get checked out for deviated septum or enlarged adenoids or tonsils. Stop smoking. Avoid alchohol and heavy meals before bed. Sleep on your side with a tennis ball in your pj pocket so you stay that way. Do throat exercises. Not saying everyone has to do this, but I would be darned if I would let things I can control spoil my lifestyle.

 

[BigT]

Only a weekend here and there??!!!!!!!

A weekend here and there!!!!!?????????

Locusts, kayaks, alternators!!!!

Arggghhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhhh

How does that change your recommendations?    

And for the record, when you were giving me that advise, I was planning for full-time use (I still am, eventually).  

I need to reread this entire thread to see what people were suggesting before they knew I didn't want to vent the battery. 

gcal.  I'm not overweight and exercise regularly, my septum and adenoids are fine, and I've never smoked or drank.  An old back injury forces me to sleep on my back so no side-sleeping for me unfortunately.  Haven't tried the throat exercises yet, but someone here suggested sleeping more upright, like in a recliner.  They said sleeping at a 30 degree angle stopped their symptoms completely.   

Unfortunately for me, the Department Of Transportation and DMV know about my issue, so I have to prove I'm using the machine at least 70% of the time per month if I want to keep my license. 

 

[SternWake]

How does that change your recommendations?    

  
If the battery is not deeply cycled each and every day, day after day, week after week the charging regimen can be changed drastically.
You could simply have enough battery capacity for 2 nights, then at home take plug in a 25 amp automatic charger.
The battery would likely die of old age before it used up its cycle life.  NO solar, no charge controller, no worrying about engine battery or hooking  it to the alternator.
Heck a weekend here and there you could likely just get a jumper pack and run the Cpap off your current engine starting battery, and when that battery fails, replace it with a marine battery.
With 300 watts of solar, in a weekend here and there on a 27-ns AGM, heck the battery would die of old age before you cycled it to death or killed it from chronic undercharging or not charging the greedy agm at a high enough rate.

 

[BigT]

If I connect my 190W panel via my MPPT cc to my OEM, under-hood 12V battery, and maybe buy one of these (just in case) http://www.amazon.com/gp/product/B0...rd_t=36701&pf_rd_p=2090149782&pf_rd_i=desktop , would that be OK for powering a .35 - .50 (estimated) Amp-per-hr. CPAP, or would the OEM battery suffer a painful and premature death from repeated, albeit occasional and minor, cycles?

Or have I beaten this to death so badly that if I ask one more question you'll send someone to my house with a bazooka?

 

[Optimistic Paranoid]

If I connect my 190W panel via my MPPT cc to my OEM, under-hood 12V battery, and maybe buy one of these (just in case)  http://www.amazon.com/gp/product/B0...rd_t=36701&pf_rd_p=2090149782&pf_rd_i=desktop , would that be OK for powering a .35 - .50 (estimated) Amp-per-hr. CPAP, or would the OEM battery suffer a painful and premature death from repeated, albeit occasional and minor, cycles?  

Or have I beaten this to death so badly that if I ask one more question you'll send someone to my house with a bazooka?

Don't be silly. Bazookas are expensive and hard to come by.  Molotov Cocktails, on the other hand . . .

But seriously.  Roughly whereabouts are you, and where do you anticipate going for your camping trips?  During which seasons?  Boondocking or using established campgrounds?

Solar panels only make sense if you are not going to be parked under trees.  And if you are NOT parking under trees during much of the year, your rig is going to get HOT.  For what you're doing, a portable panel with a long wire makes more sense.  Bob did a nice blog post on that a little while back.

I think we've pretty well established that you could get by nicely with a marine battery (not necessarily an AGM one) under your hood,  A jump pack for emergencies, and MAYBE a good battery charger back at your sticks and bricks to finish topping it up if you aren't driving long distances home from the camping. 

Regards
John

 

[Optimistic Paranoid]

Did you see this?

http://www.cheaprvliving.com/blog/installing-flexible-solar-panels-from-the-side-of-the-van/

Regards
John