Thanks for your reply!
I would guess that external push buttons need to be connected with pulldown resistor to pin 4 and 19.
So basically, Lilypad doesn't have a button, right? Do you mean I need to connect my Lilypad with a pulldown resistor to make a button?
just a guess (I don't own one), ON will turn the board ON, CHG will be to CHarGe the battery
Thank you, that sounds make sense to me 