Beefy CPAP battery setup that can be taken on a plane

[mitzvahtime]

Hi all, I will be flying to Hawaii in August and will be doing 7 nights of car camping. I need to come up with a battery solution to power my CPAP for a full night at a time (I will have access to electrical outlet charging during the day, but not at night). I have read a number of the battery posts on Apnea Board, but I haven't found anything that really fits my criteria. To be specific, I'm up against several constraints:

1) Turning off the humidifier is not an option for me, since I have chronic sinus issues. My resmed 11 pulls ~5A / 55-65W. My preferred mask (f30i) doesn't work with humidity / moisture exchangers (HMEs).
2) Airline regulations only allow <160Wh batteries on an airplane. I can bring up to 4 of those batteries, between me + my gf.
3) I would like to get 8 hours of CPAP use.

I currently own a Flashfish 151Wh portable power station and a "Resmed 11 DC Adapter 65W 12V to 24V Car DC Converter". (Sorry, the message board won't let me post links.) It runs my CPAP for about 2 hours.

My question is, is there a way to efficiently daisy-chain four 151Wh power stations together to combine to 8 hours of CPAP power? I can plug each battery into the next one, but I imagine that will be catastrophically inefficient and get nowhere close to 8 hours.

Barring that, do folks have any other ideas? I suppose I can buy a deep cycle marine battery on-island and discard it after a week, but that seems quite wasteful.

Thanks!

[sleeepyman]

Hello. I also have a resmed airsense 11 and am looking into battery solutions. I am wondering what you ended up deciding to go with? Thanks.

[mitzvahtime]

I ended up buying four 12ah LiFePO4 batteries and wiring them together in parallel. The batteries + 10 amp charger + adapters + wiring ended up being like $280 all in. More expensive than ideal, but I now have a one-size-fits-all solution that I can take on planes. Assembling it was less of an ordeal than I expected. I could have gotten by with 3 batteries, but opted for four to get an abundant margin of safety. Economizing a bit on humidification, I can make it last two full nights.

I returned the Flashfish -- it ended up having far less power than advertised.

Here are the search terms for the items I bought, mostly off of Amazon:

• 4x Redodo 12V 12Ah LiFePO4 Battery (4x $50)
  
• Resmed 11 DC Adapter 65W 12V to 24V Car DC Converter ($38, ugh, also one might be able to avoid this by connecting the batteries in series-parallel -- I didn't, mostly out of a fear of electrocuting myself)
  
• 10-Amp Battery Charger, 12V/10A 24V/5A Smart Automatic Maintainer Trickle Charger with Temperature Compensation for Car Motorcycle Lawn Mower Lear-Acid AGM LiFePO4 Battery ($20)
  
• Female Cigarette Lighter Socket, Y Type Terminal Plug Adapter with Heavy Duty Extension Cable 10A Fuse 12/24V 16AWG Cord 1.6FT(2 Pack) ($8)
  
• smseace 30PCS Piggyback Spade Terminal 12-10AWG Yellow Terminals Semi-Insulated Piggy Back Spade Crimp Wire Terminal Quick Connector PBDD-Y ($8)
  
• 6 feet of 10-AWG Stranded Copper THHN Wire (from Lowes, $4)
  

I borrowed a friend's wire crimper to attach the wires to the Y terminals.

Main downside is that it 100% looks like I'm carrying around an IED (see picture). Happy to answer more questions, just let me know.