an electrical energy source to charge said {HEAD ~ electrical circuit}, said {TAIL ~ electrical energy source} having an electrical output means 
an electrical energy source to charge said { HEAD ~ electrical circuit } , said { TAIL ~ electrical energy source } having an electrical output means
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH