This has happened so many times, that I now just charge them after every 2 hour usage. They are GREAT! I wish they were available in half sizes. I have a pair of AT M40s and she has open-backed AKG K240s. And Willa Todd was so freakin cute! However, unlike my previous three pairs, they chafed badly between my toes. After reading the review, I went with size 4 (Im normally 4. The book was written by Becky Cummings and illustrated by Zuzana Svobodova. I am probably going to have to send them back. I work a lot with my hands in the messy food industry and in general am pretty clumsy, so my watch otherwise would take a beating.