In electric vehicles, voltage and temperature sensors installed at the battery cell level or pack level are crucial for providing accurate information so the battery management system (BMS) can perform its functions properly. In this paper, a model-based sensor fault estimation scheme using a sliding mode technique has been proposed. Voltage and temperature models have been developed for a Lithium-ion battery cell. Then, a sliding mode observer has been proposed to estimate the systems’ states as well as sensors fault signals independently and simultaneously. Nissan Leaf Gen4 2018 Lithium-ion cells have been selected to evaluate the performance of the proposed estimation scheme. Simulation results under different test scenarios have confirmed the feasibility and effectiveness of the developed method.