I really couldn't say with any accuracy.
I've been plugging it in for short periods pretty frequently, so I haven't experienced a full-to-empty lifecycle yet.
Plus, the page numbering is kinda funky, so judging how many page flips you had by using the total pages in the couple books you read on a single charge isn't worth much.
I wrote a post that might explain why you're not getting the advertised 8000 pages:
https://www.mobileread.com/forums/sho...3&postcount=60