A method and system for accurately estimating one or more vehicle battery parameters, such as state-of-charge (SOC). In an exemplary embodiment, a battery control module gathers standard battery readings for estimating SOC at a relatively slow sampling rate. The battery control module receives adjustment data from one or more control modules located around the vehicle, where the control modules gather readings at faster sampling rates and then provide the information to the slower battery control module. The adjustment data from the faster control modules is representative of energy consumption and/or generation events that occur in between the readings taken by the battery control module at the slower sampling rate, and enable the method to make a more accurate and complete estimate of SOC.