I have 2 pairs of 3s 5k 20/30c zippys and I only had an issue with 1 pair.. But it was because my RX8 bust into flames. My older pair are still running just fine on my Castle esc. The newer pair work fine again thanks to some soldering work :) 1 cell had become disconnected on the 1 pack, and the other pack a cell was about to become disconnected on the other pack, both the middle cell. When the esc went it it must have surged pretty hard, Ive never felt wires that hot before
