The green lights also consume electricity!
Measured with the meter, 1.5 watts of electricity is consumed when the lights are green with the station fully occupied ... quite a bit!
I switch the whole thing off via the power strip.
PowerA is a name, like HORI, Sony, Samsung, etc. Both are connected via USB and therefore differ mainly only in their names, otherwise they are identical. The charging intelligence comes from the Joy-Con.
Could well be the USB part that supplies the power. Mine stay green once they are charged. Unless there is a power interruption to the Joycon, then it turns red again until the charging station is convinced that the Joycons are fully charged.