good luck as its still very hard to remove even with a pump and braid, to much heat and you destroy the tracks.
although you have a good point about cracked solder, if the pin has not been knocked in a resolder is usually all that needs doing, scrape some more track to copper to allow extra solder for a better connection and it can give you years more trouble free charging
you can see if its worked by powering up the mobo while out the case or placing the battery in the contacts to see if the charge light comes on.