Dual batteries now Zero power

Is it possible to destroy the batteries while soldering wires to them? Cuz the surface on the batteries really didn't like solder, so I was working on it for a while, and now I have zero power, one battery or two, but I hook it up to the charger and it runs fine. Now I have 2 batteries here. Could I possibly have destroyed 2 friggin batteries? Has this happened to anyone else?


HELP!

I just took it out for a final evaluation before I do my homework (you know, studying for my test in college chem of materials tomorrow and writing that paper) and discovered that the reason I have no power is probably because of all the crap built up from the soldering, so I scraped some of it off and lo! I have juice! Very very very little, but thats probably cuz it needs a recharge. Now, to solder the wires back together to make my external charger internal again. Man I really screwed this operation up tonight. Oh well, maybe I'll buy a clone and try my luck there before doing any more sketchy stuff to my Microsizer. My 3.8 motor and gearset should be plenty of speed.

EDIT: and I now have no left turning, boy did I #$%^ this up.