The Raspberry Pi relies on a linear regulator for its 3V3 rail. This dissipates a third of the energy as heat, which is a bit of a waste, if you want to power your Pi from an battery. Our solution: Replace the linear regulator with a $2 switching regulator from ebay. We also used another regulator for the 5V power, to test powering a Pi from a car battery.
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.