I disagree with link.. there are many many reasons for a lipo to swell or puff..when they do they are unsafe.. as the insulating foil now can not contain the cell material..send them back to trak power and see tell them ur story maybe u'll get a New pack..storing at full charge is the last reason a cell will Puff.. it might loose capacity but will not puff thats a misnomer there..I also have a set of trakpower saddle paks that puffed after 2 years of use..1 cell just lost all voltage while charging and the other took full charge to 6 volts and the other has 2.4..opps no balance outlet at the time..