As an update, I’ll just say that mom has decided she can’t be without the BiPap.  While she does not want oxygen, she has realized that the BiPap helps her breathe without forcing in oxygen.  She hates it, but she’s working with it.  The truth is, we can’t risk being without it at all now, so we’re in a new adjustment period of figuring out ways to still do things and yet have power handy and nearby.  Since I can’t afford it, it’s up to her if she thinks it’s worth it to spend $500 on a portable battery for the BiPap.  I’m all for it but it’s not my decision.