What goes on, exactly, inside those AAA batteries powering your LED flashlight? The short answer is: Chemistry. Chemical reactions can encourage electrons to flow out from one terminal and back to the other, doing some useful work along the way. Meanwhile, inside the battery, positive ions, also known as electron-holes, are changing places. Eventually the chemical reactions run down, and the battery stops delivering power. If it is a rechargeable type, you can force the electrons and the positive ions to go back where they started, ready to run again.
Make a robot friend with Adafruit’s CRICKIT – A Creative Robotics & Interactive Construction Kit. It’s an add-on to our popular Circuit Playground Express, FEATHER and other platforms to make and program robots with CircuitPython, MakeCode, and Arduino. Start controlling motors, servos, solenoids. You also get signal pins, capacitive touch sensors, a NeoPixel driver and amplified speaker output. It complements & extends your boards so you can still use all the goodies on the microcontroller, now you have a robotics playground as well.