My Passport Wireless Pro

Hi, so after months of waiting and getting data rescued off of a dying external hard drive I was finally able to get the My Passport Wireless Pro backI bought on Amazon. I absolutely love this thing. It was charging fine this morning but when I went out for a few minutes and came back, I noticed the device was stuck at 92% charged, and it said it was charging. I tried resetting it (by holding down the two buttons), and it seems to stay where it is.

So I guess my question is, how long do I have to wait until it’s fully charged?