Final answer:
Battery packs and battery chargers extend the usage of mobile devices and offer convenience to users. They provide additional power sources and the ability to recharge the device's battery.
Step-by-step explanation:
Battery packs and battery chargers are significant accessories for mobile devices because they extend the usage of these devices. Extra battery packs provide an additional power source that can be used when the device's internal battery is depleted. Battery chargers, on the other hand, allow users to recharge the batteries of their mobile devices, ensuring that they remain functional even when the internal battery runs out of power.
One practical consideration for users is the convenience offered by these accessories. Extra battery packs can be easily swapped with the internal battery of a mobile device, allowing for uninterrupted usage. Battery chargers can be used to recharge the device's battery when it is not in use, ensuring that it is ready for use whenever needed.