A vehicle includes a traction battery and a controller coupled to the traction battery and having a memory, the controller being programmed to control the traction battery based on a difference between a total resistance indicated by voltage and current at a first operating condition and a battery cell resistance associated with the first operating condition previously stored in the memory, the difference being indicative of a wiring resistance associated with electrical connectors such as wires, cables, bus bars, and the like of the battery. The battery or the vehicle may be controlled in response to the adaptively determined wiring resistance by adjusting subsequent voltage or current determinations used to determine state of charge and battery capacity and/or to control charging or discharging of the battery and selection of various vehicle operating modes.