Following the interest in the compact CWX-2 Board, but for other battery powered projects, we have made a bare bones version of the board available, called CWX-2B
This board includes the Battery Monitor and Light Sensor, so allowing you to add your own GPIO or I2C sensors and interfaces.
The CWX-2B includes the Wemos D1 Compatibility, meaning you have continuity for easily developing your code, or using our examples as a template.