Methods, systems, and devices for temperature-dependent charging of supercapacitor energy storage units of asset tracking devices are provided. An example method for temperature-dependent charging involves obtaining a temperature reading measured at an asset tracking device, the asset tracking device located at an asset to monitor travel of the asset, determining a target voltage for a supercapacitor energy storage unit of the asset tracking device based on the temperature reading to balance utilization of a capacity of the supercapacitor energy storage unit against temperature-dependent deterioration of the supercapacitor energy storage unit, and controlling a charging interface of the asset tracking device to charge the supercapacitor energy storage unit to the target voltage.