Originally Posted by billdelong

With my 406duo I always charge my 4S-6Ah packs at 20A and depending on depth of discharge it usually takes 15-20 min to get them topped off. I always check the IR of the cells at the end of each charge cycle to make sure the cells are close to 1 mΩ ... I get nervous when any of the cells are farther than 1mΩ apart and I downgrade a pack to a practice pack when any individual cell goes above 7mΩ... I discard the pack when any cell goes above 15mΩ as a personal preference.