I charge mine about once a month, having read 3-4 books per charge depending on page length. All my books are sideloaded, which I believe takes more "power" to read than ones loaded onto the KT hard drive, so I'm okay with the battery consumption - well, not really, I'd like mine to be fully charged FOREVER, lol!
My husband charges his when it gets slightly below 1/2 charge, which drives me as I think it's *so* bad for the battery. But will he listen??
Thanks for the reply, I guess you were right, it just didn't have enough power to turn on. After charging it for 6 hours, it's little battery says "Full" and I'm ready to get back to my book.