[MetalMan]

Many of the newer 20C packs are safe to be charged at 2C or even 3C, but it WILL reduce pack life. However, a form of active balancing should be going at the same time, since a small imbalance in the cells would be amplified 2 or 3 times. An example of active balancing would be like the Thunder Power 1010C charger and 210V balancer communicating together, where the balancer can cause the charger to slow down the charge rate if the imbalance is too large.