Samsung Phone battery?

Good morning everyone! We are on the lookout for a battery to test in our phone..We have a Samsung Nexus Galaxy? 4 year old phone we bought in Canada, and we THINK the battery is dead.It is not available here in Mexico ( so far, anyway) If you happen to have one of those phones and are willing to let us try the battery to be sure it IS that, we would sure appreciate it. ALSO, if you know of a very good cellular phone "fixer" that would be great, too...
Thanks so much!! Donna