A method for a battery pack controller of an electrified vehicle, the battery pack controller including one or more processors, includes identifying N battery cells of a battery pack that includes M battery cells, the N battery cells being weakest battery cells of the battery pack, wherein N is an integer greater than zero and less than M. The method includes determining one or more first parameters for each of the N battery cells, each of the one or more first parameters indicating a parameter for a specific battery cell. The method includes estimating one or more second parameters for the battery pack based on the one or more first parameters for each of the N battery cells, each of the one or more second parameters indicating a parameter for the battery pack. The method also includes outputting the one or more second parameters for the battery pack.