Pimoroni has a range of products. Here is a generic batter management board with simultaneous charging: https://shop.pimoroni.com/products/lipo-amigo?variant=39

Pimoroni has a range of products. Here is a generic batter management board with simultaneous charging: https://shop.pimoroni.com/products/lipo-amigo?variant=39779302539347 https://shop.pimoroni.com/products/lipo-amigo?variant=397793... You can also get version to fit the Pico, or even a RP2040 based board with integrated battery management.