Looking 4 suggestions on CPAP, recharging batteries and dual batteries?

[Crossfaced]

My situation is this...

I have a Jeep JKU. We are going on a cross country (USA) trip this year. We are going to be off grid 90% of the time. I need to power a CPAP machine. On 12v it draws 2.5 amps for 30 watts. In the past we have hooked the cpap up to a deep cycle marine battery and could easily get about 12 hours out of the battery when fully charged. Again, in the past charging this battery up was no issue because we usually were camped in a campground and had access to 120v so I could charge up the battery.

Is there an effective way to charge a deep cycle battery using either the alternator, or does anyone know of a 12v noun battery charger I can use in conjunction with my 12v cigarette style plug in the back of the jeep? I wasn't able to find a charger for this.

Another option....I have run the cpap off the jeeps battery using the onboard 120v inverter. In fact we did this 3 nights in a row and just drove the jeep the next day to recharge. This seems like it may be an option but.... if in fact we do kill the battery out boondockin we're stuck.

What if I were to get a HD dual purpose battery like a Yellow top Optima,Odyssey or even a Duracell AGM and installed in my jeep....that would probably work too. Yet I still have concern about killing the battery.

One other thing...money is an issue here. I need to watch my budget. I'd love the get a dual battery system but they seem to be very expensive. If there is a budget minded option here let me know...

So....any suggestions?

 

[tarditi]

How about a jump pack in case the battery gets drained to non-start state?

An expensive way to go is a Goal0 Yeti and boulder panels to charge when not hooked up to 12v to top off.

 

[BigSwede]

I have a large single battery in my rig (group 31 AGM) that I power a CPAP and fridge with overnight. I carry one of those little lithium jumpstarters as backup, but I've never had to use it.

Are you running a humidifier? My CPAP draws 1.6 amps according to the manufacturer, without a humidifier.

 

[Crossfaced]

I have a large single battery in my rig (group 31 AGM) that I power a CPAP and fridge with overnight. I carry one of those little lithium jumpstarters as backup, but I've never had to use it.

Are you running a humidifier? My CPAP draws 1.6 amps according to the manufacturer, without a humidifier.

No humidifier...

Thanks Tarditi....a jump pack is a thought I was considering as is the Goal Zero.

 

[dwh]

http://forum.expeditionportal.com/threads/172079-CPAP-Power-Questions?highlight=Cpap

 

[javajoe79]

http://forum.expeditionportal.com/t...ke-a-cheap-isolated-dual-battery-setup-for-50

 

[CCH]

My buddy has a CPAP and we've been trying to get things figured out on the cheap as well. He has invested in a Duracell AGM Marine battery and a Battery Tender smart charger. Running without the humidifier as he plans, we may not need to re-charge on the trip, but the plan is to plug the charger into an inverter while on the road. Hopefully that works out.

 

[dwh]

My buddy has a CPAP and we've been trying to get things figured out on the cheap as well. He has invested in a Duracell AGM Marine battery and a Battery Tender smart charger. Running without the humidifier as he plans, we may not need to re-charge on the trip, but the plan is to plug the charger into an inverter while on the road. Hopefully that works out.

The problem is that it takes a lot of hours to recharge a lead-acid battery.

A 400w inverter could feed a 25a battery charger (as long as the engine is running of course).

I'd say, "Screw the tender, get a real charger." 15a should do a decent job as long as he runs it ~4 hours or more. 8 hours if he wants to actually get the battery back up to 100%.

 

[CCH]

For what it's worth, it's the plus version designed for gel batteries (works with any though), still nowhere near a 25a charger. However, there are a couple of factors. First is space, the JKU is pretty full. The battery itself is killer as it needs some air and straps. Making ventilated room for a full size charger plus the battery is problematic. Second, he plans to leave the battery out with me for annual trips, and needs the smart charger for maintenance. I'll see what space we can make, and maybe we'll use my regular charger.

Crossfaced, hope this is helping, not trying to distract from your post, but have been grappling with the same issue.

 

[rayra]

These standard wheelchair / mobility cart replacement batteries can be arranged to fit in much tighter circumstances than a group 34/74/78 auto battery -

https://www.amazon.com/dp/B00LRUGE0W/_encoding=UTF8?coliid=I1HYG9HCU4E05B&colid=QWZ1BSZYG6VW

That four-pack would yield ~42Ah, ~80% of the average auto battery capacity and they are SLA, no ventilation issue (not that there really is for modern auto or AGM batteries, anyway). And due to their compact size they can be arranged almost any way you want to have them fit in with the rest of your vehicle cargo concerns. An array of 3-4 of these batteries would give sufficient capacity for two nights of CPAP without exceeding 50% drain. Wire them so they get charged by your vehicle or a solar panel and you can extend their use over more days.

I'm experimenting with mockups of these batteries for adding additional solar collection / integration and battery storage capacity to my Suburban, some pics here -
http://forum.expeditionportal.com/t...on-my-inputs-and-ouputs?p=2171879#post2171879

 

[dwh]

For what it's worth, it's the plus version designed for gel batteries (works with any though), still nowhere near a 25a charger.

Um, is the battery to be charged a gel? They usually have lower voltage limits, so a charger designed for gel might be set to a lower voltage.

Which will still work but would add even more hours to get the battery charged.

 

[vtsoundman]

Use a 100ah sealed agm from united battery. $130 on Amazon. Great battery for small draws like your CPAP. Measute the actual current the CPAP draws. If it's labeled for say 2a, it likely uses less. Charge using ctek dc/dc charger from the vehicle while driving. There are others that may DC /DC chargers. It'll give a solid 20a. My testing yields great results on charge times. Using an inverter to run a charger doesn't make a whole lot of sense...and a huge efficiency hit.

A goal zero has little capacity vs cost...it is great for people that want something compact and fully integrated. I think it is overpriced for what it is.

sent via the cone of silence