Building a Small System for camping off grid.

[Bongerscc]

I am trying to build a small system so I can use my

Resmed AirSense™ 11 CPAP​

Standard AC Input: 100-240V, 50-60Hz, 2.0A, It has an 65 watt power cord that plugs in to the wall.
The battery says that it does 109 AH.

I really do not have a lot of money and I am trying to do this on a budget. The system would be used 8 hour during the night and charge during the day. I am just trying to see if this would work. Latter on I thought I could change out the battery to something nicer. Would it be best to hook this up series vs parallel? What controller would work well. I know that I need a pure sine wave inverter. I would be on one lake for 4 days, 5 days on the next and then 5 days out in the middle of no where for sure. I could use my truck to run things but do not want to waste the gas.

 

[Bob B]

With the cheap price of some of the ready made LiFe batteries now days, I wouldn't waste money with a lead battery .... build things up to support the LiFe from the get go.

Looks to Will's videos for reviews of some of the 100 AH batteries. Buy one that can be used in parallel to support future expansion.

 

[JWLV]

With the parts that you listed and proposed to build, this prebuilt Bluetti is nearly equivalent without wires everywhere and easy to carry and move around. Bluetti has been well reviewed.

https://www.amazon.com/BLUETTI-Portable-EB3A-Recharge-Generator/dp/B09WW3CTF4

If you don't like Bluetti, there are many other brands to choose from, such as Rockpals, Anker, Ecoflow, Jackery, etc. Most of them can be charged from the 12v port of your car or from an AC outlet. Most of them include a MC4 adapter cable to charge from solar panels. If it doesn't you can just buy a cable for about $10.

 

[JWLV]

Here's a video by Will Prowse where he reviews several of these small portable power stations. It's from 4 years ago so some of these are no longer available or have been updated.

 

[timselectric]

You might want to check the cord for a DC power supply. (Between the AC plug and the CPAP)
Every portable CPAP machine that I have seen runs on 12vdc.
And uses a power supply.
If yours is the same, it will run directly from a 12v battery. No inverter necessary.

 

[Coaldust]

You might want to check with the manufacture as most C-PAP machines have a 12v power cable available (My ResMed does).
I got mine from my VA provider

 

[dopeassjackson]

Buy a premade setup. The cheapest other option would be to buy a $80 marine battery and charge it off your vehicle.

I have a friend who durring a storm ran his oil fired boiler off a inverter hooked to his toyota Corolla battery. He just let it idle all night. Used next to no gas he said.

 

[Bongerscc]

With the parts that you listed and proposed to build, this prebuilt Bluetti is nearly equivalent without wires everywhere and easy to carry and move around. Bluetti has been well reviewed.

https://www.amazon.com/BLUETTI-Portable-EB3A-Recharge-Generator/dp/B09WW3CTF4

If you don't like Bluetti, there are many other brands to choose from, such as Rockpals, Anker, Ecoflow, Jackery, etc. Most of them can be charged from the 12v port of your car or from an AC outlet. Most of them include a MC4 adapter cable to charge from solar panels. If it doesn't you can just buy a cable for about $10.



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With the parts that you listed and proposed to build, this prebuilt Bluetti is nearly equivalent without wires everywhere and easy to carry and move around. Bluetti has been well reviewed.

https://www.amazon.com/BLUETTI-Portable-EB3A-Recharge-Generator/dp/B09WW3CTF4

If you don't like Bluetti, there are many other brands to choose from, such as Rockpals, Anker, Ecoflow, Jackery, etc. Most of them can be charged from the 12v port of your car or from an AC outlet. Most of them include a MC4 adapter cable to charge from solar panels. If it doesn't you can just buy a cable for about $10.



View attachment 204707 View attachment 204709

268Wh for $300.??? The $93 deep cycle battery is at. 109 amp hours times 12votts is 1308 watt hours, right??? The typical power consumption of my cpap is approximately 56.1 watts, but it may peak at 75 watts. 120v divided 75 watts is 1.6 amps an hour. After doing the math and looking at these very small prebuilt systems, I was going to build my own for the compacity.

 

[Bongerscc]

With the cheap price of some of the ready made LiFe batteries now days, I wouldn't waste money with a lead battery .... build things up to support the LiFe from the get go.

Looks to Will's videos for reviews of some of the 100 AH batteries. Buy one that can be used in parallel to support future expansion.

$252 vs $93, that is $159 that I can need to spend on the rest. Money is tight man. I understand that the other battery is great, but if this will last me two years then I can upgrade that is great.

 

[Bongerscc]

I will be camping for days and do not need to run my truck all day to charge things up. A 2010 tundra uses gas. I will be our in some rough deep woods and mountains. No gas station new by. Prebuilt systems are cute and all but over priced and they do not have compacity.

 

[Bongerscc]

I want compacity at a cheap price. Lead Acid is the way that I have to go for that right now. I need to be able to run things off the son, that is why I am on a DIY solar Forum. The math sucks on this and I just wanted someone to double check the math on things and would the parts listed be a good fit???? I am in rough deep woods for days and would not be coming down the mountains just to charge things. If I had tons of money sure I could spend $1500 prebuilt system or a or $300 just for one battery but I do not. Big Truck can charge things but I will be out of gas, that is why I would like to use solar to help curve things.

 

[Bongerscc]

You might want to check with the manufacture as most C-PAP machines have a 12v power cable available (My ResMed does).
I got mine from my VA provider

I have seen a cable that can plug in to the car, but just that cable is $100 and that will use gas. Trying to stay away from gas, and if I have to spend $100 for a cable might as well put it to the solar anyways and use the cable that I have. I am looking for off grid, but wife says I need my machine.

 

[Bongerscc]

You might want to check the cord for a DC power supply. (Between the AC plug and the CPAP)
Every portable CPAP machine that I have seen runs on 12vdc.
And uses a power supply.
If yours is the same, it will run directly from a 12v battery. No inverter necessary.

Mine is a home unit that runs from the wall outlet, not a portable unit that has a battery pack.

 

[Bongerscc]

BLUETTI AC180 Solar Portable Power Station | 1,800W 1,152Wh​

4.9 (235 reviews)|Ask a question
US$999.00

If I did the math right.
96Ah

That $93 dollar battery from Walmart has 109 ah. at an tenth of the cost????

 

[Bob B]

$252 vs $93, that is $159 that I can need to spend on the rest. Money is tight man. I understand that the other battery is great, but if this will last me two years then I can upgrade that is great.

But that means you wasted $93.
There's also a huge difference in usable capacity. You could by a 50 AH LFP and have almost the same capacity of a 100AH lead.

 

[Andrewr05]

BLUETTI AC180 Solar Portable Power Station | 1,800W 1,152Wh​

4.9 (235 reviews)|Ask a question
US$999.00

If I did the math right.
96Ah

That $93 dollar battery from Walmart has 109 ah. at an tenth of the cost????

But that has an inverter, solar charge controller, AC charger and DC regulated output and it's all built in a box with a handle.

You can't really compare a bare battery to a whole unit.

Also that's not even a good deal, you can regularly get that for $400-500 on eBay refurb directly from Bluetti.


For what you are trying to do, you really need to consider going with a LiFePO4 battery or a standalone power station.

What is your budget?

An

 

[Bongerscc]

But that means you wasted $93.
There's also a huge difference in usable capacity. You could by a 50 AH LFP and have almost the same capacity of a 100AH lead.

I did find an 100AH LFP for $169 that was much better than that $252.

 

[Bob B]

I did find an 100AH LFP for $169 that was much better than that $252.

Before you buy an ultra cheap LFP I'd post questions about the specific battery on here to see if anyone has experience with it.

Will has good reviews on the LiTime batteries ...... https://www.amazon.com/Ampere-Time-...a?sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY

 

[Bongerscc]

I am really trying to stay at $400 or less, There is a place in town that sells batteries that are dent and scratch, I was going to talk to them and see what they got. I just look, at those prebuilt systems and their capacity, $$$$$, and I still need panels. I was like better to build my own. Their capacity is trash for the $$$$$. I could use a battery that is laying around as well. I just want to go fishing and use this Cpap, so I do not die in my sleep, lol.

 

[JWLV]

Car/marine batteries are rarely shown with amp-hour ratings. But from what I could find a typical 27DC battery is around 80 to 90 AH. With any lead acid battery, the useable capacity is about 50%. At best, you can get 45 AH out of a 27DC battery. Don't forget that an inverter will have an idle draw of anywhere from 20 watts to 50 watts or more from just being turned on.

I'm not trying to convince you to buy any particular type of battery or power station. I have no stake in any of this. I'm just trying to give you some advice on your choices. But it seems like your mind is already made up. I've already done what you are wanting to do. I've used 27DC batteries with solar several years ago. I regretted it almost instantly. Back then, LiFePo batteries were so expensive that I could not have afforded even the smallest LiFePo battery. If I had someone give me advice about it back then, I would have made a better decision.