Flat enzyme-based lactate biofuel cell (ELBC) integrated with power management system (PMS) was developed as a potential power supply for wearable sensors. Kinetic models of power output and chemical reagent concentration (lactate oxidase LOx and lactate) were developed to determine the limiting factor of the ELBC performance. Given the lactate concentration (0-40 mM) in human sweat, the optimum LOx amount coated on the anode ranged from 6U to 54U based on the experimental maximum power output. In the ELBC-PMS entity simulation test, power discharge recharge frequency was calculated for self-sustained sensing and data transmission, indicating that the ELBC could support wearable sensors (power requirement: 1-1350 mW; signal transfer frequency: 1-1320 times/h). The electrochemical activity of LOx coated anode was validated using the cyclic voltammetry (CV). The coefficient of variance and regression statistical analysis revealed the high stability and long lifespan (2 weeks) of ELBC without the need of lactate refill. Published by Elsevier Ltd.