One thing I ended up doing with my mini (14500) was take a old credit card/store card/some plastic and cut a strip about .5 inches wide by about 1.5 inches long. take a ruler, or just by hand and crease the center of the plastic lengthwise so it looks like a wide "V". Place the plastic on the right side of where the battery would go in and then wedge your battery in. the crease int eh plastic keeps the battery shoved over so the firing pin hits the battery dead center each time
