WeMos D1 Mini ESP8266 WiFi Module with 18650 Battery Shield

This board pairs a WeMos D1 Mini's ESP-WROOM-02 WiFi module with a battery shield built specifically for an 18650 Li-ion cell, so a project can run untethered instead of needing to stay plugged into USB. The shield handles charging through the TP5410 circuit with a 5V boost output, and includes overcharge and over-discharge protection built in, which matters more with Li-ion cells than most other chemistries since getting that wrong is a real safety issue.

An onboard AD input with a built-in dividing resistor makes it straightforward to monitor the battery voltage from code, so a project can report its own charge level rather than just running until it silently stops. The auto-program circuit keeps the same one-cable flashing convenience as a standard WeMos D1 Mini.

Suited to portable IoT sensors, wearable-adjacent projects, and anything that needs to run on battery for hours or days rather than sitting next to a wall outlet.