Thanks for the replies.
Well it turns I out I stored them batteries and screwed them at the same time.
I spoke with a Thunder Power guy and he said the storage voltage should be 3.8-3.9 volts a cell or approx 50% charge. Storing at 100% is what caused the batteries to swell. He also went on to say any swelling is no good and there a risk of fire at that point.
Lesson learned...I was too busy running my monster trucks to pay attention...
