I have a Yaesu equivalent FNB-27 battery and I lost the charger. I
picked up a replacement from Radio Shack last night, but I don't know
if tip should be positive or negative, and couldn't easily take the
battery apart. It's stone-cold dead, so I can't just hook up a meter
to it. Any info would be appreciated.

Also, the charger that I got is a 500mAh charger, I just noticed that
this is a Ni-MH battery. I'm not going to have any issues, am I?