More House Battery Power Needed, help!!!

[unreng]

Does the van have solar or a shore power connection or some way to recharge the batteries each day?

The cheapest option is to add a third interstate battery with battery cables...this should work as long as the batteries can be recharged every day.

Presuming the interstate 24M's are installed on the exterior and if there is no room for a third, a sealed AGM battery could be installed inside the van and properly sized battery cables connected to the existing interstate batteries!
This is a workable solution although not an optimal solution.

FYI - The interstate 24M battery is not a sealed AGM battery. The website above goes to interstate batteries that are sealed AGM...part #DCM0075

Here's the documentation for the Dreamstation CPAP

And some websites that discuss CPAP's in RV's:
https://heartlandrvs.com/blog/lifest...-the-road.html
https://www.cpap.com/blog/cpap-camping/
https://www.cpap.com/blog/cpap-battery-secrets/
https://blog.cheapcpapsupplies.com/power-cpap-rv/
https://www.healthsqyre.com/educatio...-traveling-rv/

battery specs:
https://www.interstatebatteries.com/products/24m-xhd
Group Size 24MS
Part Number 24M-XHD
Cold Cranking Amps 800
Cranking Amps 1000
(RC) Min @ 25 Amp 135
Length 11"
Width 6 7/8"
Height 9 1/2"
Weight 44.6lbs
75 Ah
Cost = $130+tax

To provide an idea of cost, here are two options for lithium batteries...but they're way more expensive than lead batteries ~$2000 for 200Ah + upgrades to wiring or accessories to mesh with the existing electrical system.
Two battleborn lithium batteries might work?
Two lion energy batteries might work?

[mobilemaster341]

Thanks everyone. I think that an additional 24M Deep Cell InterBattery, when added under the gaucho, should be enough to supply 2 CPAPs for 1 night. That brings the total battery bank to 3 24M Deep Cell batteries. I need 6.8 amps for each CPAP. IF YOU THINKI NEED MORE, PLEASE LET ME KNOE, AND THANKS5

[mobilemaster341]

I believe that a third InterState 24m will provide an additional 80, bringing the tool to
240. I think that should be enough to get me through the night. I'll be driving the van at least 5 hours the next day. Additionally I've learned that that inoperable 2.8 Onan Generator should be able to be repaired. I think I have a workable solution. Would you agree?

[Cyrull]

If you can heat up the water for your humidifier before putting it in, lowering the tube temperature will help reduce power consumption but have the same desired effect enough to get you to fall asleep comfortably. Similar to deep freezing your fridge on shore power before plugging it in to your house battery.

Also, if your battery is low it may not have enough juice to start your CPAP when it starts to ramp, especially if you start both of them at the same time. If you can idle your van for the first few minutes while your CPAP starts to ramp that will also help stretch out your battery.

[arctictraveller]

6.8Ah each for 8 hours equals about 110Ah a day, not including any other loads on the battery's. Additionally, due to inefficiency's, you need to replace more amp hours than you use for a full recharge, so five hours of driving may not be enough to fully recharge your batteries back to 100%. No matter what is wrong with your generator, getting it running is certainly possible, and will add a nice layer of insurance to your travels.

[daveb]

A couple of things to consider.

Adding a new battery to an existing set of old batteries is not generally a good idea if they are not isolated from each other. Avoid mixing (banking) difference types, different size and sometimes even different makes of batteries.



Best to keep it as simple as possible. Have you considered using a single larger AGM battery?



AGM's charge a bit quicker than standard flooded batteries, can be installed in various position flooded battery can't, and need no water level maintenance.

[doublevan2]

greetings Mobilemaster361 -- I'm in similar situation with cpaps -- mine is a small Z1 cpap and I run mine off of an Amazon available for sale - orange battery "box" - has 2 - AC outlets, 2 12 volt outlets - small "floodlight - USB, etc. They run about $250 or so - can charge up via AC or 12 volt - they run two claps for like 2-3 night (7-8 hours_. A lot cheaper than running to Austin ! If you stay in a motel after like 2-3 nights - plug 'em in and charge away !

[doublevan2]

Hey Mobilemaster 361 -- Try this link for options for CPAP power -again cheaper and portable for use ! https://5productreviews.com/best-por...th-ac-outlets/

[chut2k]

Here's another possible approach: There are many 12 volt and 5 volt USB ultrasonic humidifiers from various internet sources. I would expect these to use much less power than the heated humidifiers used in the 120 volt CPAPS. The volume inside a passenger vehicle is not great, and you may be able to get an acceptable humidity level with the CPAPs' humidifiers turned off. Windows will be fogged in the AM (I'm 77 and have a CPAP also. Remember the drive-in movies when dating?)

[mobilemaster341]

Thanks for the info, and the links, I'll check them out