I will go away for a week and want some extra batterytime for my EKEN.I had problems fitting a extra battery behind the motherboard,resulted in pressure shadows on the display and not optimal function of the buttons.I cut wires abd soldered the leads from the two batteries to the motherboard connector and with the soldering iron cut a window on the back cover,glued batteries and added some silicone.The hinges was vulnerable and glued all togheter and some paint.Works OK,time will show if I have got some more miliamps