【Ideas】 Battery can have "memory" too - USB battery

Hello everyone, my name is AA-USB. I am a "little精灵" with a dual identity. I am both a small battery that can provide power for your flashlight and radio, and a memory stick USB drive that can help you save some good-looking movies and nice-sounding songs. I have a capacity of 4GB. When you press my head and feet with two fingers respectively, my body will light up to show my current energy status. When I am low on power, remember to charge me, because I am your good helper!