A metal detector is an instrument used to locate metal objects. It can effectively discover metal inclusions concealed within items or buried underground. Typically, it consists of a handheld sensor that can be swept over surfaces or objects. When the sensor detects metal, either a change in tone through earphones or a moving indicator needle indicates its presence. Ideal for security checks, this device is commonly used in transportation hubs, border control, educational institutions, legal settings, event venues, and factories. Experts often recommend using Nickel-Metal Hydride Batteries (NI-MN) for the best performance. Although their capacity is 2-3 times higher than Nickel-Cadmium batteries, harsh weather conditions such as low temperatures can impact their capacity.