Need portable power for my CPAP machine

[wb9wb]

Hey everyone,

I need some suggestions for a portable power source to power my CPAP machine.
(It's a breathing machine because I have sleep apnea.)
I need something that is battery powered because I'll be camping in parks that don't allow generators to run at night, and obviously my CPAP runs at night...
Last weekend I thought this would be a good solution so I bought this thing:
http://www.canadiantire.ca/en/pdp/motomaster-eliminator-powerbox-1600-0112014p.html

But... It only powered my CPAP for about 3.5 hours and then there was no juice left in the powerbox. I need something that can supply about 7 hours of power.

I also won't have regular access to 120V electricity to charge up this portable power unit, but I could charge it in my vehicle driving around during the day.

So any ideas out there?

For what its worth, I bought a deep cycle marine battery from walmart a few years ago. I believe it was this model. https://www.walmart.com/ip/EverStart-Maxx-Marine-Battery-Group-Size-29DC/20531539
It was new, and I hooked up my Rem star CPAP via a 12VDC cord at a #12 setting to it after a full charge . It lasted 5 days and on the 6th day it died and choked me at 3am..


I did this to see how long I would need it during a power outage. It now lives in a battery box with its two brothers, hooked to my sump pump backup system.

I am looking for a charging solution for this same style battery for my Jeep JK when I go camping.

 

[cobound]

Heads up, Home Depot has them for $349.95 right now

It’s an online buy, I’m going in tomorrow to see if I can get my veterans discount on top of that, but either way...might just grab one for that price!

Thought I’d let others know, who knows how long that price will last!!

 

[BigSwede]

Seems like you all are overthinking this. Just get a CPAP that runs off of 12 volts and run it off of the vehicle battery. I have done this for years. WAY more efficient than an inverter.

I have used a CPAP for 17 years now. Currently I have a Devilbiss IntelliPap. According to Devilbiss it uses 1.3 amps, so it doesn't even noticeably draw down the battery overnight. In fact, I run the CPAP and an Engel fridge on a Group 34 Odyssey overnight, no problem at all. Note: this is without a humidifier. Humidifiers are power hogs, and having a CPAP without a humidifier is WAY better than not having one at all.

If I am tenting I have a 25 foot 12V power cord I run from the battery. If I sleep in the vehicle I have a 12V outlet in the back.

 

[cobound]

You're absolutely correct, I'm overthinking it! I haven't gotten my 12v cord yet, hoping by this weekend I'll have it so I can test my direct to battery time...need to slow down

I can't seem to find the amp draw on my CPAP, but it doesn't have a separate humidifier, so I'm guessing I should be good for more days than I'll actually be in the woods.

OK, not to hijack this thread, but this has all been very helpful so far...wondering if you could confirm as I'm just now getting it, I think.

My CPAP is an AirMini:

with a 12v converter it uses a very small amount of power, mainly due to the waterless humidification. The AirMini typical power consumption is 6.3W, with its peak power consumption at 27W. Its power consumption in Standby mode is 1W.

That said, typical run would be .52 amps or 4.16 amps used over 8 hours. Peak is 2.25 amps or 18 amps used over 8 hours (what I'm factoring my sleep to be - I never get 8, but better to figure over than under).
Optima Yellowtop battery is 75 amp hours...so at typical I'd get 18 uses and at peak I'd get 4 uses.

Am I on the right track?

Thanx,

B

 

[BigSwede]

Keep in mind, you generally want to avoid drawing down a lead-acid battery beyond 50% to avoid drastically shortening battery life.

 

[cobound]

Yes, I’m seeing that...looks like the lithium Goal Zero is the key, or just build my own setup.

I just need to see what my needs are after a few more outings and not jump.

 

[rnArmy]

I would love to get a Goal Zero 400 for my camping needs (and for my buddy's CPAP machine). However... the lithium version states you can't charge it from your vehicle's 12-volt system (110 or solar power for charging). So that would be an issue for me since I would want to be charging it when driving.

https://www.goalzero.com/shop/power-stations/yeti-400-lithium-portable-power-station/

From their website (link above)

Two Ways to Charge the Yeti 400 Lithium

Recharge from the sun by connecting a compatible solar panel. Charge time is dependent on the size of the solar panel. The Boulder 100 Briefcase will fully recharge the Yeti 400 Lithium in about 8-16 hours.

Plug it into the wall. Fully recharges in about 7 hours.

DO NOT ATTEMPT TO CHARGE YOUR YETI LITHIUM FROM A 12V SOURCE. Doing so may cause damage to the unit.

 

[dwh]

So use an inverter to charge the Yeti from 110v while driving. The engine/alternator is supplying the power so conversion inefficiency is a non-issue.