Spot

Thanks Sierra and you're correct about not needing the deep cycle battery, just added expense for no real benefit in this case. Not sure why I even put deep cycle in the post, Freudian slip maybe?

Sealed AGM it is rated at about 50AH (or 100AH if I want a large margin for error).

Just tried the DC to DC convertor after determining on the chart that I would need a 50AH deep cycle battery, put my Fluke in series with it and maximum current draw was just under 4.5amps and that occurred when I took the mask off and the pump went open circuit for a few seconds, most of the time it was drawing between 2 and 3 amps so 50AH will be more than adequate.

Update on initial thread.

Hi Guys, Went to use my ResMed 10 again last night and would you believe it starts "hunting" again and I know it's not the filter so was thinking this machine will have to go for service. As I was making sure all the hoses were connected properly I pushed on the water tank and it moved just the smallest amount, maybe a millimeter or two and bingo pressure drops to normal and all is well!!!

So the original problem wasn't the filter at all, it was the tank not being fully seated which I presume creates a leak significant enough to cause the hunting but not enough to shut the pump down - makes me feel like a bit of a dill but there it is. Reminds me of the KISS principle.

In addition Sierra, I have obtained one of the ResMed 12 to 24 transformers as suggested but am still to set it up and test it, thanks for the link to the battery guide, very helpful.

All good ideas, I will look into the ResMed 12 to 24 converter and I have the batteries and charger covered however I'd be interested to know the amp hour capacity of the 12volt battery you talk about Sierra?

Hi Sierra, Will be very interested to hear your report on the filter "trial" in 3 months time, my pump and consumables are supplied at no cost to me by Veteran's Affairs here in Australia, I get a package every 6 months, heated hose, water tank, filters , headgear and nasal pillows and going by ResMed prices to you that adds up to a significant amount of money in running costs. I note the "service life" of the ResMed 10 is 5 years so will be interesting to see if they send me a new one at that time. I have had 2 of the Power Station II battery pack's supplied however both of them will only run the pump for about 4 hours if the heater is left running which is a little disappointing given in this country that's nearly $1k's worth!

No repeat of the hunting problem since the change of filter so I'm pretty certain that was the culprit, very odd to say the least, my filter was clean compared to yours.

Wow, ouch is a good description Sierra, your filter is so much worse than mine, just out of curiosity I weighed my old filter and a new one, came up with a consistent difference of 1 grain, not sure that means much apart from it's doing it's job.

Have to agree with you that my issue might not be that simple but my machine worked fine for 7 hours, let's see what future nights bring!!

It's one of those issues were you don't know if you're all starting from the same baseline, you know 4. 8volts here 5.0 volts there, can't imagine all the semi conductors and transducers came from the same batch so we will always get variations. Anyway good thing you've changed those out!!!!

PSATB - couldn't agree more, horses for courses, should have seen some of the filters we pulled out of tanks and 113's, they had it all, hot, wet, dry, humid, dusty, muddy - and worse!!!!

Hi PSATB, Yes, will do with the schedules and have attached a side by side of the dirty filter and a new one, as you can see it's discoloured but there's no loose dirt or dust, is it possible the filter was manufactured with a little more density than normal - will never know.

I'm a little surprised they didn't build some form of cyclonic block into the inlet side, some of these machines operate in wide range of environments.

The manual states the air inlet filter should be replaced every 6 months, I'm surprised I didn't get some form of error message as well as the user guide states an error 004 may be a blocked air filter among others.

Hi Sierra and PSATB, A follow up to my original post, I used the pump for 7 hours last night and it was good as gold, so the original issue was certainly caused by a restricted inlet filter, it's not the original, I do remember changing it 6 months or so ago. If I'm able to find it I will take a photo of it next to a new one and post it here. Less technical people may not think to work through a fault finding process and might well incur significant inconvenience and cost trying to get their machine "fixed"

Hi, I went to use my ResMed Autosense 10 last night however instead of it starting gently at a 4 on autoramp the air pressure was up, down all over the place "hunting" we called it in the automotive industry.

Switched it off and slept without it and do decided to do some basic checks for obstructions etc.. as these machines aren't cheap and I don't have a spare.

Took a look at the inlet air filter and although it was a little discoloured I would be hard pressed to say I thought it was blocked however I changed it and the machine seems ok again although tonight will be the test.

My question is has any one else found their ResMed to be sensitive to air inlet obstruction?

Hi Everyone, Hopefully the image I uploaded is visible and it's in the right place, first time I've tried!! I'm struggling to understand why when I have a single event just before 01:20 the graph remains high until 2:20. I assume that it's possibly to do with how the Resmed Autosense 10 "resets" it's data collection but I have no real basis to make that assumption.