I really wouldn't have your remove-able link that way round. Anything could fall on the male pins and short them together activating the robot. Also it looks like you've tied to pull far too much current through the XT60 and it's charred the end. Try using XT90-S with the female end in the robot and the male end as the removable link.

You also need to insulate the soldered terminals of your connectors, insulation tape will work however clear heatshink is best.