How old are they? The c-ratings that you listed are pretty low that's why I ask. I had 2 Venom 3800 35c packs and 2 Venom 5000 40c packs that I ran for 3 years with no puffing and replaced because they started going flat. Only stopped buying Venom because their prices were getting pretty high. I only balance charged them every couple months and never storage charged them. On the flip side, I had 2 SMC 7200 that I always balance and storage charged and they both puffed, bad.