Portable radios rely on batteries as their power source. Since these radios are for mobility, they require a power supply that is also portable. Dry cells are used as a power source for these types of communication devices. The battery voltage can vary depending on the design of the radio, with options such as 12 volts or 7.5 volts. Additionally, the battery's capacity (measured in mAh) is determined by the radio's current consumption, with values ranging from 1500mAh to 3000mAh and beyond.
One way to understand a battery's capacity is by looking at its milliampere-hour (mAh) rating. For example, a battery with a 2000mAh rating can provide a continuous current of 2000 milliamperes per second for an hour. Batteries are made using different chemical compositions, such as Ni-Cd, Ni-MH, Li-ion, or Li-poly. The manufacturer of a radio device often produces batteries specifically designed to fit the device's specifications. These batteries are rechargeable, which means they can be reused after being depleted, ensuring continuous operation of the device.