Computer guru needed

Good morning, and happy 4th!
I have an older Toshiba laptop that I have been planning to take on my upcoming cruise. It has Windows Vista operating system. The battery was shot so I purchased a new one. When I have it plugged in and using it, the battery icon says it has 0% available and is charging. But it has been two days and hasn't charged a bit.
What am I doing wrong?
Thanks, my trip begins in two days and I would like to have this available...
C