battery backup recommendations as10/as11

[Charliejoe]

Thank you robbob

I have checked both fuses and they both are fine. I check the voltage from the socket to the negative post and it was 13 V.
I use my IKFD brick now, which does not have a green light. I’d sent the ResMed brick back, and no longer have it for my use.

I put everything together plugged it into the CPAP. Nothing happened. I disconnected from the battery and plugged it in to the 12 V cigarette lighter in the car and it works great every time. (As it has for the last five tests that I’ve done over the last week).


 The only difference in these tests is the power source. It’s 12 V, 77 Ah, which seems to be adequate and you seem to agree. I don’t know how to test this further and I have read statements from others on this site that have claimed that it works well. I just don’t know what’s missing and it’s making me nuts .

[robbob2112]

It has to be your adapter between the battery connections and the socket then.  

On my setup one of the sockets came with the tab at the bottom pushed flush verse standing up a little bit.  So when I plugged into it the pin wasn't making a connection in the center.   A dental pick and I bent it up about 1/8th inch and it works fine except the power adapter gets loose and backs out.

Can you take that and hook to your regular car battery then try it?

[Charliejoe]

I agree that it had to be the adapter socket, although I was not able to raise the contact up at all. So  for my next test, I tried to bypass the socket and just hot wire the brick’s plug to my battery. That produced one tiny spark, and my brick stopped operating! ….Oops 
I think I’ll be buying a new dc voltage converter brick and a new battery connection adapter now.


Almost every brick looks the same on Amazon. There are at least seven and they all cost $32-$39. Do you know of any particular brand is more reliable than the rest?

(As I recall, Thomas Edison had many similar results trying to perfect a light bulb.)

[robbob2112]

did you replace the fuse in the tip of the brick connector?  The spark was the capcacitors inside the brick charging.  If it just doesn't work the surge current might have blown the fuse.  That wouldn't help if you wired it backwards though.  The center tip is positive and the outside is negative.  And 

Personally I use the real thing - the machine is to expensive to chance it with knockoffs that might not work right or regulate the voltage correctly.  I got mine on black friday sale for $69.  But, I see 25% off sales from the various vendors all the time.  Look at vendors from the top and pick one.

Here is an idea about what might be wrong - your battery is 12v - should technically be reading 12.8v.  Now your car lighter when the engine is running is is 13.7 volts perhaps the boost/buck converter in the brick isn't good enough to go from the slightly weaker voltage?  

Now, you can get a wire that goes directly from 2 series batteries to the machine.   They take 24v.  So long as the charger was never hooked up at the same time as the machine it works.  But, this seems a bit risky to me as there is no regulation that way and if you burn the main board it costs a couple hundred to send in for repairs.

Robert

[Charliejoe]

Robert, it seems that the brick was the problem after all. I never should’ve bought the bargain unit. The $89 brick made all the difference. I now agree with you. It is well worth the money. Now I will start testing my set up to see how many nights I get from one fully charged 77 amp hour battery. Thanks again for your advice.

(Charlie) Joe