Choosing a Battery

CapnLoki wrote:I started looking into smaller, simpler setups because a number of people posted that this is too complicated and anything that required drilling holes and soldering wires was beyond their capabilities.

I'm all about smaller, simpler solution too. That why I like your U1 battery suggestion - don't want to carry around 50lbs. But I haven't found anything like the MinnKota Power Center for a U1 size battery, so I don't see any alternatives to buying a U1 battery box and drilling holes for charging cables, 12V hookup, etc..

CapnLoki wrote:feel that "all-in-one" jumpstarters or UPS's are a better solution

I purchased a Jump-n-Carry JNC660 just under 2 years ago, I tried running my CPAP machine off of it for the first time the other night out of curiosity. I woke up 8.5 hours later and my Airsense 10 was still running. Surprised how well that worked. I turned off humidifier and ClimateLineAir hose. I have the official ResMed DC Converter 24V 90W plugged right into JNC660.

davecpap wrote:

CapnLoki wrote:I started looking into smaller, simpler setups because a number of people posted that this is too complicated and anything that required drilling holes and soldering wires was beyond their capabilities.

I'm all about smaller, simpler solution too. That why I like your U1 battery suggestion - don't want to carry around 50lbs. But I haven't found anything like the MinnKota Power Center for a U1 size battery, so I don't see any alternatives to buying a U1 battery box and drilling holes for charging cables, 12V hookup, etc..

You don't need a box like the MinnKota, though I understand why some folks want it. With older "flooded" batteries a box was needed because of the possibility of leaking. New AGM batteries will not leak, even if inverted - they were designed for jet fighters! The primary risk now is shorting the contacts, which can be protected against with terminal boots or a simple $10 U1 box which comes with handles and "holes" for the wire to pass through. No drilling is needed! Its true that the charger would be outside that box, but for car camping, that's probably desirable.
http://www.amazon.com/NOCO-HM082BKS-Gro ... B002WCUIC4

davecpap wrote:I purchased a Jump-n-Carry JNC660 just under 2 years ago, I tried running my CPAP machine off of it for the first time the other night out of curiosity. I woke up 8.5 hours later and my Airsense 10 was still running. Surprised how well that worked. I turned off humidifier and ClimateLineAir hose. I have the official ResMed DC Converter 24V 90W plugged right into JNC660.

This jump-starter uses an 18 Amp-hour battery, plenty for one or two (maybe three) nights without humidity. For many folks, this will work fine. I favor the separate battery path because I can have twice the power for about the same money and not much more weight. I can also have a high quality charger that work with several batteries - in other words I could have a cheap, light 8 AH battery for a single night trip, and also a large battery ready for a major outage, or to use with the humidifier.

Thanks CapnLoki for posting this information. I put together a battery system using the scooter battery you listed and the Resmed DC converter for my AutoSense 10.
I did power it up on battery and I am going to give it a running/use test soon with heat and humidity off.

Anyone talk about or bring up lifepo4 batteries yet as an option

https://www.arkportablepower.com/blogs/ ... s-and-cons

USMCVet wrote:Anyone talk about or bring up lifepo4 batteries yet as an option

https://www.arkportablepower.com/blogs/ ... s-and-cons

I would love to see an affordable LiFePO4 battery - they have a great combination of high power, low weight, safety, and lead-acid compatibility. Unfortunately, they seem to be very expensive, like 5-10 times the AGM cost. Also, the specs often lie: when you see "Pb Eq" it means they are inflating the spec by a factor of three compared to a lead battery. There is some logic to this with starting batteries, but it is a blatant lie when applied to deep cycle.

Note that Ark doesn't sell batteries, they sell boxes and panels, and recommend AGM batteries.

I have small back up power thing that runs off a 40ah lifepo4. This is the actual battery it uses. http://www.batteryspace.com/lifepo4-pri ... 4-dgr.aspx . Pair it with an appropriate charger and balance module and it's a decent option I think but honestly I'm not an expert.

USMCVet wrote:I have small back up power thing that runs off a 40ah lifepo4. This is the actual battery it uses. http://www.batteryspace.com/lifepo4-pri ... 4-dgr.aspx . Pair it with an appropriate charger and balance module and it's a decent option I think but honestly I'm not an expert.

Looks like a very decent option. The 40ah rating gives you as much usable power as a much larger and therefore much, much heavier lead acid battery, and it’ll last a good ten years without being fussed over. Buy once and forget, and it’ll still work when the power goes down unexpectedly. The problem for me with a backup system is that it sits unused for many months at a time, and when you need it, it must be charged and ready to go. Lead acid isn’t very good at that.

My run test worked fine. I plan on connecting the battery tender weekly to top off and running off battery for a night occasionally to test. I looked at the price of the LiFePO4 battery. (I think I will stick with this setup)

I have both sleep apnea and a heart condition, and I already have a pretty pricey battery for the scooter I use due to the heart condition. The owner's manual says it is "25.2V 11.25Ah Li-Ion" and the website says it's "274WH": https://shop.travelscoot.com/us/accesso ... 283wh.html

I'd like to go camping with my family, and I'm wondering if I can use the scooter battery with my CPAP (a ResMed) without the humidifier. I'm guessing there will be at most 3-4 days of camping in any one place, after which we'll drive to another place.

Specifically, I'm wondering if it would work to:
- Buy the ResMed DC/DC converter
- Figure out some way to connect between the scooter battery's flat connector and the CPAP plug (any suggestions here would be great)
- Use a car inverter and the charger that came with the scooter to charge the battery on driving days

Any advice would be appreciated!

noahwf wrote:I have both sleep apnea and a heart condition, and I already have a pretty pricey battery for the scooter I use due to the heart condition. The owner's manual says it is "25.2V 11.25Ah Li-Ion" and the website says it's "274WH": https://shop.travelscoot.com/us/accesso ... 283wh.html

I'd like to go camping with my family, and I'm wondering if I can use the scooter battery with my CPAP (a ResMed) without the humidifier. I'm guessing there will be at most 3-4 days of camping in any one place, after which we'll drive to another place.

Specifically, I'm wondering if it would work to:
- Buy the ResMed DC/DC converter
- Figure out some way to connect between the scooter battery's flat connector and the CPAP plug (any suggestions here would be great)
- Use a car inverter and the charger that came with the scooter to charge the battery on driving days

Any advice would be appreciated!

Happy New Year and Welcome to the group!

You've asked a good question with several interesting aspects.

First, assuming you have a modern ResMed device, you'll want the ResMed DC Converter for your pump (about $85) because it has the proprietary ResMed plug and circuitry that sends a signal to the pump. (The plug comes on the ResMed AC supplies, the DC Converter, and a few custom battery systems.) Its a little known fact that the converter works fine with 24 Volt sources such as your battery, as well as more common 12 Volt sources.

Second, you have to consider whether the battery is sufficient for your needs. Normally I do these calculations in 12 volt amp-hours, but for this case I'll use Watt-hours. Normal 8-hour usage for modern ResMed and Respironics pumps is 40 to 100 Watt-hours depending on the settings, the leak rate, and the altitude. I figure about 50 Watt-hours for my Respironics 560 at pressure 10 at sea-level. So your 4 night trip could be about 200 watt-hours assuming similar usage. This is well within the rating of your battery.

You don't mention the type of connectors for the battery. Many batteries this size use "lugs" that can be easily bolted to a connector like this:
https://www.amazon.com/Battery-Tender-0 ... B004JV6OMO
Which can connect to a socket such as:
https://www.amazon.com/Battery-Tender-0 ... B0041CDPQO
Care must be taken that no one uses the socket assuming its a normal 12V supply, as it ill be 24V. You should put a serious warning label on it!

If your battery doesn't allow connecting with a ring, you'll have find an alternative, but anyone handy with electrical stuff (including many boat owners and computer or ham radio hackers, etc.) should be able to help. You could take the ring connector I listed to a Radio Shack (if you can find one) and they would probably crimp on the right connector for the cost of a six-pack.

Your thought of charging with an inverter running from the car is workable but has a few issues. One is that its rather inefficient, so it will cost twice as much power as you used. This is not a problem if the engine is running, but if you tried to do a complete recharge without the engine, you could easily drop the battery below the point where it can start the engine. The second issue is that a full recharge takes about 5 hours, and you probably don't want to leave the car running all day at the campsite. On the other hand, if you were going out for an hour drive during the day, plugging the battery into an inverter/charger setup could add significant juice to the battery, stretching out the time the battery can cover.

I would be remiss if I did not point out a more cost effective alternative: A U1 AGM scooter battery provides 35 amp-hours, which is about 420 watt-hours. The AGM is a bit less forgiving of deep discharge than the Lithium, so you might consider them the same useful capacity. The AGM is about $65 compared to the $800 (with shipping) of the Lithium pack. The downside of course is that the AGM is 24 pounds, while the Lithium is about 4 pounds. AGMs come in a variety of sizes, so if you had several, you could put on the same quick-connect cables (as listed above), use the same charger and swap them as needed.

Thanks so much for the quick and helpful reply!

I wish I knew the name of the battery connector. It's flat, plastic, and snaps together with a connector on the scooter side. There's a small image of it here (the black connector on the right side):
https://shop.travelscoot.com/us/accesso ... ter-a.html

I was really hoping to find a way to keep using this battery for my scooter (since I already have it) while also occasionally using it for my CPAP (while camping). But I think this connector is probably going to keep that from working. I don't want to replace the connector, or mess with the battery in any way (because right now it's supposedly certified to take on airplanes and such, but won't be if it's modified). But I also probably can't figure out a way to bridge between that connector and the RedMed DC converter.

So probably the smarter solution is to just get a separate battery for running the CPAP while camping. I like the sound of the U1 AGM scooter battery option and will read through this thread to figure out the other things I need to get (BatteryTender, cigarette lighter socket, etc).

noahwf wrote:Thanks so much for the quick and helpful reply!

I wish I knew the name of the battery connector. It's flat, plastic, and snaps together with a connector on the scooter side. There's a small image of it here (the black connector on the right side):
https://shop.travelscoot.com/us/accesso ... ter-a.html

I was really hoping to find a way to keep using this battery for my scooter (since I already have it) while also occasionally using it for my CPAP (while camping). But I think this connector is probably going to keep that from working. I don't want to replace the connector, or mess with the battery in any way (because right now it's supposedly certified to take on airplanes and such, but won't be if it's modified). But I also probably can't figure out a way to bridge between that connector and the RedMed DC converter.

So probably the smarter solution is to just get a separate battery for running the CPAP while camping. I like the sound of the U1 AGM scooter battery option and will read through this thread to figure out the other things I need to get (BatteryTender, cigarette lighter socket, etc).

Well, part of me is thinking it would take 5 minutes to splice the adapter onto a socket (cause that's what I do), and part is thinking I'd rather not risk the expensive lithium on a camping trip where you can con a young nephew into lugging around the cheap AGM! Whatever works for you.

Had a good test of the capnLoki battery setup recently. Three days with no power here in the NE. Ran with no hose heat and humidity set to 0 each night.
Plenty of power and was able to charge smartphone too.
Thanks CapnLoki!

Pennywise wrote: ↑

Tue Mar 13, 2018 6:14 pm

Had a good test of the capnLoki battery setup recently. Three days with no power here in the NE. Ran with no hose heat and humidity set to 0 each night.
Plenty of power and was able to charge smartphone too.
Thanks CapnLoki!

You're Welcome!

Pugsy, change his nickname to "CapnBattery"... it's appropriate