The Cortex solar panel was installed inside the brain jar above the power unit's top level. The bottom of the panel is fit to the top ledge of the battery holder, which holds the bottom of the solar panel in place without any hardware. The top of the solar panel has two angle brackets holding it, connected together as shown. The back side of the solar panel has a sticky substance which nicely grips the angle bracket's long extension side. It can also serve as a wire holder as shown.
This is the larger solar panel rated at 3 volts and 120 mA designed to power the brain and trickle charge the batteries during the day. Tests show the panel works in available room lighting.
Index to the Brain Cortex
http://humanoidolabs.blogspot.tw/2013/11/brain-cortex-index-part-16.html