CPAP and battery usage while dry camping

[tomkatb]

With a cpap you could run it on 120 ac with an inverter however they use about 20% more battery that way. Inverters are 80-90% efficient.

A cpap is a fairly large user. Check your manual. Dc amps x the number of hours used.

Check your battery size. You likely have only 40 amps available. One night for sure. Two will damage the battery.

Thus you need more batteries or a way to recharge. Solar or generator.

In rv’s the battery system is the weak link. Likely if you turn the furnace on as well, the DW will wake you about 2:30 because the heat went off!

Often the “free” battery from the dealer is sized to operate the brakes on your trip home when you buy it. Not a great amount more!

Plan ahead. My plan is four gc2 batteries. 5x the batteries you likely have.

[jdaddy33]

This is the battery I have now. A. How do I determine how many amps available? B. If I'm going to add a second battery should I add another one of these, which I'm assuming is Group 24, or should I add 2 of something better? What would be the next step up?

Originally Posted by tomkatb

With a cpap you could run it on 120 ac with an inverter however they use about 20% more battery that way. Inverters are 80-90% efficient.

A cpap is a fairly large user. Check your manual. Dc amps x the number of hours used.

Check your battery size. You likely have only 40 amps available. One night for sure. Two will damage the battery.

Thus you need more batteries or a way to recharge. Solar or generator.

In rv’s the battery system is the weak link. Likely if you turn the furnace on as well, the DW will wake you about 2:30 because the heat went off!

Often the “free” battery from the dealer is sized to operate the brakes on your trip home when you buy it. Not a great amount more!

Plan ahead. My plan is four gc2 batteries. 5x the batteries you likely have.

[tomkatb]

You have about 80 amps in the battery. Yours is a car battery. As you should not discharge more than 50% that means you have about 40 amps dc available.

If the battery is relatively new you can add another identical one likely.

It is a questionable idea to add a new to a old battery. Depends too how much damage you have done to it already.

Two Costco GC2 batteries cost $180 and will give you about 115 amps and last 3 times as long likely if you take care of them. Assumes you have a place for them.

Likely would last three or four nights. There are other loads on the battery. Run the furnace and you might not make the second night. Got to learn power management.

[bikendan]

Originally Posted by jdaddy33

This is the battery I have now. A. How do I determine how many amps available? B. If I'm going to add a second battery should I add another one of these, which I'm assuming is Group 24, or should I add 2 of something better? What would be the next step up?

Basic dual purpose marine battery that's not a true deep cycle battery.
It is a group 24.
How much dry camping or boondocking do you want to do.

[jdaddy33]

We are heading out west next summer for 3 weeks or so. I understand many of the NP campgrounds do not have electric hookups. Our longest stop at one place would be 3-4 nights.

Originally Posted by bikendan

Basic dual purpose marine battery that's not a true deep cycle battery.
It is a group 24.
How much dry camping or boondocking do you want to do.

[jdaddy33]

So just summarizing (and feel free to correct me if I'm wrong). For longer amp hours with using the CPAP, it would be best to go with 2 GC2 6v batteries (and I should connect those up in a series correct?). PS - Says my CPAP on DC uses 6.67 A.

As for a new battery compartment to house the two new GC2's does it matter what type of battery box? Looks like my battery tray on my TT frame is 8 inches wide, but 23 3/4 inches long. Also, am I correct in understanding the GC2 batteries can be run down to 80%, instead of 50% like the Group 24 I have now? I plan to add a more reliable battery monitor inside the TT. Still have to figure out if I'm going to go solar or generator to recharge batteries while boon docking.

[Tom48]

Originally Posted by jdaddy33

This is the battery I have now. A. How do I determine how many amps available? B. If I'm going to add a second battery should I add another one of these, which I'm assuming is Group 24, or should I add 2 of something better? What would be the next step up?

GR24 are usually 65 to about 70 maybe 80 if you buy a real expensive one, amps. Two of them still isn't much.
2 golf cart batteries sit in the same footprint if you have the height and BY height I mean the battery box is about 3 inch taller. 2 golf cart batteries will give you between 208 and 235 amps depending on brand and quality that you buy. Anyway you slice it that means over a hundred USABLE Amps which is generally speaking about the equivalent of 3 GR24 BATTS.

[Tom48]

Originally Posted by jdaddy33

So just summarizing (and feel free to correct me if I'm wrong). For longer amp hours with using the CPAP, it would be best to go with 2 GC2 6v batteries (and I should connect those up in a series correct?). PS - Says my CPAP on DC uses 6.67 A.

As for a new battery compartment to house the two new GC2's does it matter what type of battery box? Looks like my battery tray on my TT frame is 8 inches wide, but 23 3/4 inches long. Also, am I correct in understanding the GC2 batteries can be run down to 80%, instead of 50% like the Group 24 I have now? I plan to add a more reliable battery monitor inside the TT. Still have to figure out if I'm going to go solar or generator to recharge batteries while boon docking.

Anytime you discharge your battery you're using some of its life. Generally we think 50% use of available power does least damage per cycle. some golf cart batteries, probably because golf cart batteries get abused in golf carts everyday, publisher specification based on discharging 80%. Again, anyway you slice it, he will be shortening my life for those batteries if you run them down that far. Since the low voltage cutoff for most inverters is around 11 volts I suppose the world thinks using batteries down below 12 volts is an okay idea. Generally speaking 12 volts is 50% on a wet lead acid battery. I try never to take mine below 12.2 volts on a bad day. I run SLA batteries currently and the specs on many of those say that they can be discharged to 80% routinely but again I know that shortens their life.

What is it potato potahto you can find a specification that will meet your needs if you look hard enough but generally just remember discharging below 12 volts rested voltage is hard on a battery. Any battery. Oh except maybe a lithium battery because there's puppies are dead before you get them down to 12 volts and most manufacture say it's okay to run a lithium battery dead as long as you have a proper lithium charger that can wake it up again. I'm building a set of lithium batteries for my RV and I will never run them dead. I will set my cut off at 20% so I never have to literally revive a dead battery.

[chriscowles]

Originally Posted by jdaddy33

So just summarizing (and feel free to correct me if I'm wrong). For longer amp hours with using the CPAP, it would be best to go with 2 GC2 6v batteries (and I should connect those up in a series correct?). PS - Says my CPAP on DC uses 6.67 A.

As for a new battery compartment to house the two new GC2's does it matter what type of battery box? Looks like my battery tray on my TT frame is 8 inches wide, but 23 3/4 inches long. Also, am I correct in understanding the GC2 batteries can be run down to 80%, instead of 50% like the Group 24 I have now? I plan to add a more reliable battery monitor inside the TT. Still have to figure out if I'm going to go solar or generator to recharge batteries while boon docking.

Two GC2s (or 2 Group 24s, which I don't recommend) will fit together in the dual battery box linked below, which is what Rockwood provided with my Mini-Lite. It fits in the stock battery rack and it's cheap.

You'll get many opinions in the solar vs generator conversation. Mine is that, without experience, you should consider a small (~15A) inverter generator. Management is straightforward, you can use it for your electrical appliances (including AC, alone) and, unless you have a large enough battery bank to skip some cloudy days with no charging, you'll probably need one, anyway.

Two 6V GC2s will serve you well with a generator for recharging. I don't think they have the necessary reserve capacity for solar charging, alone. Those with solar charging experience (I have none) may disagree. I do have experience dry camping with 2 CPAPs in National Parks.

https://www.campingworld.com/camco-d...ox-118120.html

[jdaddy33]

Thanks, that is the box I was looking at last night, so I'm going to order it. Seems like a lot of people like the Trojan T105's for the CG2 Golf Cart 6v batteries. I'll start poking around for deals on two of those.
Like you said many have opinions on solar vs generator. I'm leaning towards the below generator just because I like the idea of being able to use it for power outages at our home, and that it runs off propane as well. I know many like the Honda eu2200i's but I'm not sure I want to have to purchase two of those bad boys if I ever want to run the AC.

https://www.amazon.com/dp/B01FAWMMEY...v_ov_lig_dp_it

Originally Posted by chriscowles

Two GC2s (or 2 Group 24s, which I don't recommend) will fit together in the dual battery box linked below, which is what Rockwood provided with my Mini-Lite. It fits in the stock battery rack and it's cheap.

You'll get many opinions in the solar vs generator conversation. Mine is that, without experience, you should consider a small (~15A) inverter generator. Management is straightforward, you can use it for your electrical appliances (including AC, alone) and, unless you have a large enough battery bank to skip some cloudy days with no charging, you'll probably need one, anyway.

Two 6V GC2s will serve you well with a generator for recharging. I don't think they have the necessary reserve capacity for solar charging, alone. Those with solar charging experience (I have none) may disagree. I do have experience dry camping with 2 CPAPs in National Parks.

https://www.campingworld.com/camco-d...ox-118120.html

[upflying]

I use a Yeti Goal Zero 400 to run my 12 volt CPAP. It lasts all night with the humidifier on and 4 nights without the heated humidifier.
https://www.goalzero.com/shop/power-...power-station/

[chriscowles]

Originally Posted by jdaddy33

Like you said many have opinions on solar vs generator. I'm leaning towards the below generator just because I like the idea of being able to use it for power outages at our home, and that it runs off propane as well. I know many like the Honda eu2200i's but I'm not sure I want to have to purchase two of those bad boys if I ever want to run the AC.

Unless your Roo (from your profile) has an upgraded 15K BTU air conditioner, you don't need 30A to run it. A 15A inverter generator is sufficient, and many people do that. You have to add a hard-start capacitor on the compressor and a time-delay relay on the fan. That's easy, and costs less than $30.

The capacitor boosts the starting power and the time-delay separates the compressor start from the fan start, to reduce the peak surge. That keeps it below the generator's peak capacity. You could even skip the time-delay relay if you start the fan manually first (with the thermostat set very high) and leave the fan running, rather than on auto, but that's a pain. Also, if you do have a 15K BTU AC, you can run it on a 15A generator with a MicroAir EasyStart. (There are competitive products.) I do, and others do, too.

There are caveats, like you can't run your AC in combination with anything else on 120V (maybe a laptop?), and that high altitude reduces the power output of a generator. That may drop the generating capacity below the AC demand. I have experience with using the AC on a Honda EU2000i. We just leave everything else on 12V, but mostly we try to camp where we don't need AC if we don't have shore power. I have no experience with the high altitude effects.

I bought a Honda because it's the only brand with an authorized service center near where I live. Others would serve just as well. Just be aware that a 30A generator is heavy, and you may not run your AC much, compared to your use of the generator to recharge batteries.

[chriscowles]

Originally Posted by jdaddy33

... Seems like a lot of people like the Trojan T105's for the CG2 Golf Cart 6v batteries. I'll start poking around for deals on two of those. ...

Many people are just as satisfied with Duracell (East Penn/Deka) 215Ah GC2s from Sam's for $89. How you maintain the battery has more bearing on its longevity than does the brand name, but East Penn seems to have a good reputation.

A battery monitor will help a lot. Some swear by Victron ($$$); others are happy with a cheap knockoff ($). I'm in the latter camp but don't have an inverter, so I'm not disadvantaged by the cheap monitor not having some of the high-end capabilities of the expensive one.

Victron ($$$)
AiLi ($)
QWork ($) - includes long connector wire

[PDXMike]

I use a dream-station and use a spare battery just for it in bedroom, I have run it four over 4 days and still goes strong. I bought that ridiculously priced 12v power cord and run at 14 hg cm pressure you will be fine running off your batteries but I like to have a dedicated battery just for cpap machine. I got a alligator clip cord with power plug on other end. I sleep great and it’s not a worry about draining house batteries.

[Flat_twin]

Even with a pair of Crown 235 ah 6v batteries for the coach, we went with a stand alone lithium battery for the wife's cpap. The resmed 10 is a 24v appliance. DC converters lose a certain amount of power changing 12v to 24v. We bought a MaxOak lithium battery. It lasts four or five nights depending on the humidifier setting and can be charged with a 12v outlet in your car while you drive around.

[mcclainross]

My brother uses a Goal Zero solar generator (400 watt hour) and 100 watt solar panel to recharge every day. If there is no sun, the generator can be charged from the 12V cigarette lighter in the vehicle. We dry camp all the time and have never run out of juice.

[guy goodenough]

I use a cpap and I had a separate 12v battery. It took about 4 days. to deplete it

[snapcap14]

I personally like this
https://no.co/

[DLorenzen]

I travel with the HDM Z2. You can purchase the battery for it to run unplugged and it charges in a couple of hours (USB charge). Runs around 8 hours. Worked well for me.

[SNFR666]

I use a battery pack inverter for those nights we are dry camping. If I turn off the heater in the CPAP it will go two nights. I have also heard of people installing a small inverter to feed a single plug in the sleeping area. That with a portable solar panel would work quite well.