acer acros 575db battery

i need to change or (re)charge the battery in an acer acros 575db ; there is none on the mother board: could it be well hidden or is it an internal one? bottom line is that it needs charging. there’s an ‘outlet’ for a double-ended male cable would that be what to use. i can plug in using the normal male/female cable and in the bios it notifies that the battery is dead.

thx…..mimi v.