Battery Tender fuse

Bought bike used and this is my first time winterizing it. Previous owner had already installed the half that goes into the battery. Tried plugging into it with no change on the status of the battery tender. I decided to disassemble to investigate the connections to the battery and found the battery tender fuse is blown and was 75 amps? Is that normal? And why’s it blownEdit: just realized it’s 7.5 amps lol. Anyways gonna replace, but still any idea how it could possibly be blown? Wouldn’t want my bike catching fire via /r/motorcycles https://www.reddit.com/r/motorcycles/comments/ek9f4q/battery_tender_fuse/?utm_source=ifttt