Hi Hearts and Thoughts -
You can get a small lithium ion battery made just for bipaps - weighs about three pounds. You plug your inverter into the battery, and plug the bipap into the inverter.
You can get it at
www.CPAPUSA.com or
www.CPAPman.com. Both of these sites carry merchandise for bipap users.
Our battery lasts 10 1/2 hours, we use it every day, and it recharges pretty quickly. It is smaller than a sheet of paper and is about an inch or so thick - sleek and small.
As far as portability - we had a shelf installed on the back of the wheelchair - the battery sits on the shelf, and the bipap sits on the battery - then we strap it all onto the shelf. We hang a small bag over the back of the chair and put the inverter in the bag. VERY convenient and lightweight.
Important information: Most bipap makers do not want you to use the bipap humidifier when on the battery. It is easy to remove - we have no problems without it. Also - the battery time is very dependent on the bipap pressures. Pat is 19 and 6, which her clinic says are quite a lot. You might get even better times on the battery than we get.
Our experience is that no one in our support group has heard of this, and only the pulmonologist knew of it. We found it ourselves in an internet search. Cannot understand why the clinic does not help us with portability - it is so easy! We have been using it for months and are thrilled with it.
Good luck! Beth