A method for diagnosing an estimated battery state of charge is provided. The method includes estimating a first state of charge of a battery at a first time with a state-of-charge sensor, estimating a second state of charge of the battery at the first time, calculating a difference between the first state of charge and the second state of charge, and comparing the difference between the first state of charge and the second state of charge to a predetermined value to determine whether the battery sensor is within operating parameters. A system for estimating battery state of charge is further provided. The system includes a state-of-charge sensor configured to estimate a first state of charge of a battery at a first time, and a processor connected to the battery sensor and configured to estimate a second state of charge of the battery at the first time, and compare a difference between the first state of charge to the second state of charge to a predetermined value to determine whether the battery sensor is within operating parameters.