KLST_PANDA + Battery
quite straight forward was the integration of the 18650 rechargeable lithium-ion battery.
there is also an on-off switch at the top of the board. the board can be powered via the USB-C connector or from battery. the battery is also charged via USB-C. the charging is controlled by the charge controller TP5400.
two LEDs mounted on the back of the board indicate charging or stand-by mode ( TBH the stand-by LED is already annoying ).