A buck boost converter that can be powered from a Li-Ion battery and output 3.3V @ 500mA. Powered by the TPS63051YFFR and in the same package as a standard Adafruit buck converter. Expect to squeeze around 5-10% SoC from a typical Li-Ion battery. Input Voltage Range: 2.5V to 5.5V Assembled at pcbway.com

291105301 https://cotorelay.com/wp-content/uploads/2014/09/2900_series_reed_relay_datasheet2.pdf Reed Relays Micromin FormC Reed 7.62 816-2911-05-301 https://www.mouser.co.uk/ProductDetail/Coto-Technology/2911-05-301?qs=m0A%2FB3jbz5tBJF6yhXpDEw%3D%3D Coto Technology 2911-05-301