Solar power

[Craftymanager]

My husband uses a cpap and oxygen at night. Some of the campgrounds we use have no hook ups. What’s the best way to keep things running. Solar or generator? What is the recommended set up.

[RogerR]

Since a lot of campgrounds will not allow generators to run all night you will need to have sufficient battery reserve to last the night plus furnace and whatever other loads you have.

You might driveway camp for a night with a fully charged battery and see if it lasts all night. If it does not last than more batteries will be needed.

Solar is great and you can get foldout panels that you can aim at the sun and position away from shade if you have enough wire. But for cloudy days and places where you can't get the solar to work a small 2,000 watt generator is the answer. If you only use it to charge the battery and not for the air conditioner a small one is enough and a lot easier to handle.

[Mustang65]

Does your CPAP unit run on a 12 or 24 volt DC? Look at the output voltage on the CPAP transformer.

My CPAP uses 3 to 5Amps when running on 12DC, the humidifier is what uses most of the power. 5Amps * the hours you sleep, let's say 8 hours = 40Amp hours. If you have the standard 85Ah battery, and it is FULLY charged, you will use about half of your batteries 85Ah's, which will put the battery voltage around 12.2 volts in the morning. Not good as you have other items running in the background.

I recommend (2) 6volt 225Ah batteries to keep up with your needs, or (2) 12volt 100Ah batteries, which will give you 200Ah.

The trick is keeping them charged. Do you camp in the shade of trees? Open sunlight? Travel a lot? I recommend at least a 100watt solar panel but would go with 200 watt system. The 200 watts will compensate for those cloudy days. But there are those days, like 2 3 or 4 in a row that are not SOLAR panel friendly (cloudy/rainy) and you will need an alternative source of power. If you do not need AC, I would go with a Honda or equivalent 2000 watt generator (or 2 if you need AC) as they are VERY quiet.

I have (2) Trojan T145 6 volt batteries (in series = 12VDC) and 260Ah with 250 watts of SOLAR. I have yet to hit a day where they were not totally charged the next day, but we usually stayed in sunny spots. While traveling the SOLAR can put out 20Amps when needed which also allows us to run our refrigerator on 110VAC and not LP.

You will also need to monitor your batteries current status, as the voltage should not drop below 12.2 volts. A digital Voltage Display will give you agood idea as to the current status of your batteries.
Don
My Registry

RVing with SOLAR

[bdreinv]

Solar is a nice up grade just depends what part of the country your in,sun shine!Lots of inexpensive 2000- 2500 watt quite generators around also,6 volt deep cell batteries would be help full, and maybe a pure sine wave inverter.

[marbles]

I had an extra 12v AGM battery fro Cabelas I put next to the bed for the CPAP machine. I also bought a 90W 12v to 19v converter for the machine from ResMed. The voltage never gets to 110V AC, so it takes less power.
We can go for two nights before recharging the battery. I then run the generator and connected the extra battery to the power converter in the trailer. The spare battery was fully charged in 2 hours. I like my new Progressive Dynamics converter.
I like the idea of solar but the roof is so soft it does not hold the solar panel. The plywood on the roof is very thin. I am looking for an alternative. There is a company in town that sells solar panels and their less than perfect 365W panels are $60. Now to figure out how to mount it on the roof.

[Craftymanager]

Will this run both the cpap and oxygen machine? Thanks for your help>

[Higgy]

I use a medistrom battery for mine. Lasts the night no problem as long as your not running the heated hose and humidifier. If you do use those it might run low by early morning. This link shows you what it is.

https://www.youtube.com/watch?v=fQvqmv6xgvI