I have an Inogen2 concentrator, the best thing I have bought. There are second hand ones on the for sale site. Like you needed both my hand free and bought a backpack , brilliant once your used to it for this lady golfer.
I think firstly you need to know how much oxygen you need in litres, also be aware that portable concentrators need an air intake and extract which means they cannot be kept in a bag of any kind. You maybe better off with an oxygen cylinder that can be enclosed, either have them delivered or have a concentrator at home where you can fill up cylinders. A 1 litre cylinder on 2ltrs will last approx. 1 hour 20 mins. or if used on pulse, 5.9 hours. (Pulse is when oxygen is only given when you breathe in, not all the time). I do have a Focus concentrator for sale which is 2ltrs (I now need 3ltrs) only 8 months old, has 2 batteries, each last 1h 30m. Still over 2 years warranty left, paid £1400.00 for it, looking for £900.00. I have not put it on concentrators for sale yet. Do check with a respiratory nurse before you decide what to do. You do not want to buy a machine when it may not be the answer for you. I made a couple of mistakes, do your research don't jump into anything.
Content on HealthUnlocked does not replace the relationship between you and doctors or other healthcare professionals nor the advice you receive from them.
Never delay seeking advice or dialling emergency services because of something that you have read on HealthUnlocked.