Battery min. Amp hours help

[JustinD9]

I need to go camping in two weeks. I have my PRS1 560 that I will use without the humidifier. I am looking to get a battery that lasts max 2 nights and also small, so looking at lithium ion Deep cycle. I have found one that's 15amp hours. Given my pressure median is around 9 I would like to know from people who have covered this before whether 15amp hours is sufficient for two nights (typically 7.5hrs of sleep a night).

[Wulfman...]

Try some forum searching.

Here's one on "camping batteries".

viewtopic/t110951/search.php?keywords=camping+batteries


Den

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[amenite]

I need to go camping in two weeks. I have my PRS1 560 that I will use without the humidifier. I am looking to get a battery that lasts max 2 nights and also small, so looking at lithium ion Deep cycle. I have found one that's 15amp hours. Given my pressure median is around 9 I would like to know from people who have covered this before whether 15amp hours is sufficient for two nights (typically 7.5hrs of sleep a night).

Last time I checked my PRS 560 draws about 7 watts at fixed pressure of 14 cm for the blower alone while on AC power. If you're getting the full capacity (15 AH *12 V = 180 Watt hours) you're probably getting close to your two night limit. Are you backpacking or is weight a major factor? You could probably get more AH for the money with a good AGM. A small solar panel could give you a boost between uses.

[JustinD9]

Hi amenite, I had been working on the rated max draw of 3amps/Hr (SuperSleeper had mentioned this number I think). I had seen capnloki post saying his PRS560 runs him around 4AMP/hrs a night, which would mean I am good to go. I am just being cautious though. The battery I am looking at is light and would fit in the Respironics carry bag. I am actually going to be "glamping" but I need to carry it around and on a Ferry in this instance.

[JustinD9]

Also, the battery in question (from here in Oz) is a LiFEPo4 battery and while rated 15amphrs this is based on a 20hr rating. Not sure whether it all translates since the 20hr is based on lead acid.

[CapnLoki]

I need to go camping in two weeks. I have my PRS1 560 that I will use without the humidifier. I am looking to get a battery that lasts max 2 nights and also small, so looking at lithium ion Deep cycle. I have found one that's 15amp hours. Given my pressure median is around 9 I would like to know from people who have covered this before whether 15amp hours is sufficient for two nights (typically 7.5hrs of sleep a night).

Turns out you have the same setup as I do, and I've measured usage carefully. The answer is a 15 AH LiFePO4 pack will cover 3 nights,

details in this thread:
viewtopic.php?t=102179

EDIT: I just noticed you've seen this and wanted verification. Although I only "formally" tested this setup once, I've run without humidity on my boat about 180 times in the last three years and obsessively checked the AH meter several times a night so I have pretty high confidence in 4 AH. (My OCD comes out in a few odd ways!) Of course this assumes a direct 12V cable, not an inverter.

[JustinD9]

Thanks CapnLoki. That's great as I plan to run it without a humidifier. Yes, also a direct cable.

[amenite]

Hi amenite, I had been working on the rated max draw of 3amps/Hr (SuperSleeper had mentioned this number I think). I had seen capnloki post saying his PRS560 runs him around 4AMP/hrs a night, which would mean I am good to go. I am just being cautious though. The battery I am looking at is light and would fit in the Respironics carry bag. I am actually going to be "glamping" but I need to carry it around and on a Ferry in this instance.

What I meant by close to your two night limit was "probably three nights, and you'll be draining the battery closer to 0% that you may want". The Lithium chemistry won't be so sensitive to full discharge like the AGM I'm used to. I think you'll be fine but you need at least one trial run (or access to A/C or perhaps a spare battery as backup, never hurts to have a spare ).

I just ordered one of these and hoping to get two full nights with it, but I'll top off via solar during the day while in the field. It's my first LiFePO4 battery. Could have done without the inverter but it might be handy one day:

https://www.bioennopower.com/collection ... power-pack