portable oxygen concentrator w/batteries

I can no longer attend class or simply go to the store without taking oxygen tanks with me.  My condition is terminal, however, I would like to enjoy a quality life attending classes at Plaza Studio, going to art classes, even attending the shows and various other activities in the area.  My body is too weak to carry the multiple tanks necessary to be away from home for any length of time.  I would like to purchase a concentrator that makes it's own oxygen with the aid of batteries.  Insurance does not cover this expense and I do not have the funds available to purchase this without assistance. Please help me get back to where I can enjoy a life.