I got my Oasis 3 on Wednesday and charged it fully. I read for about an hour on Wednesday night and about an hour again last night. So around 2 hours of total reading time and I noticed I am down to 88%. I have the light at I believe either 8 or 10 and the warmth is at around 12-15 so maybe that is what is doing it? It just seems that the battery on this drains quite a bit faster than my voyage and 1st gen oasis do. I do have wifi on as well but I did always keep it on on the voyage and 1st gen oasis as well.