Usually to run their visor, their cybernetic systems (some of which are critical support systems that keep them alive), if they have synthetic/mechanical limbs they power those too and are the primary source for movement. Some protos have x86 CPUs and high end GPUs in their visor and for them the batteries run those as well.
Fuckin protogens using more power than my electric stovetop and microwave combined. What are they doing in that body of theirs???
their best
Mostly charging up their battery cells, those batteries are usually very high capacity.
Batteries are merely vessels for energy, this does not answer the question of its final purpose!
Usually to run their visor, their cybernetic systems (some of which are critical support systems that keep them alive), if they have synthetic/mechanical limbs they power those too and are the primary source for movement. Some protos have x86 CPUs and high end GPUs in their visor and for them the batteries run those as well.