Rich,

I just talked to a gal at CpapXchange and she told me that you would have to "special order" the lithium 12 AA battery pack with connector for $184 per pack...ouch   One battery pack comes with the $279 package with converter and bag etc. But since one battery pack will only do 2 nights on a Resmed9 you will have to order extra battery packs for your overnight trips ... unless you can figure out a lightweight and reliable system to recharge them in the wilderness. Solar ?

Mike