The portable they gave me, which I run at "3" when walking, only gets about an hour from battery and same with backup battery. Frustrating.
Tubing gets pinched and twisted but air still seems to come through.

My husband put a coiled spring around the area that connects to the machine . The problem is to find the right size spring that will slide over the tube. Large enough to fit over the tubing and small enough to stay where you want it. He had to put one on my big concentrator at the house too because it did the same thing.

Usually, the sales pitch for POCs uses the lowest possible setting and 15 breaths per minute to give a time for how long the battery will last. Most of us breathe far more often than 15 breaths per minute, especially if we're actually doing something, like walking and definitely when exercising. That probably accounts for the difference in what you're seeing. You might try cannulas from a place called Soft Hose on the internet. Theirs are easy to coil and don't kink, although I've never had the problem you describe with either a 4 foot or 7 foot cannula, regardless of where it came from. POCs generally are heavy and if you carry an extra battery, even more so.

Michelle, like Judge 69 said, your oxygen man who supplies your oxygen can provide whatever size you want and they may have different types that don't kink as bad. Many times how long the oxygen lasts is dependant on what setting you use. The higher, the shorter time it will last. Sometimes when I am walking or moving, I will have it set higher but when I am sitting, I turn it lower to conserve the oxygen.
Ernie71

Hi Michelle, it seems to be normal for batteries to deplete sooner than advertised. As to the tube getting messed up or kinked, simple solution : if is a true portable you carry or use as a backpack, then use only a cannula with 4 feet tubing ; if is a pull along portable like some of the continuous flow units, then use only a cannula with 7 feet tubing. Hope this helps, Best Wishes, judg69