Each battery management unit monitors a plurality of batteries and can selectively charge a selected battery via a charger and switch circuit or can selectively discharge {HEAD ~ a selected battery} via {TAIL ~ a load and switch circuit} under the control of a controller 
Each battery management unit monitors a plurality of batteries and can selectively charge a selected battery via a charger and switch circuit or can selectively discharge { HEAD ~ a selected battery } via { TAIL ~ a load and switch circuit } under the control of a controller
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH