The battery pack, which includes one rechargeable cell and optional circuitry, has {HEAD ~ an exterior housing} that is generally rectangular in {TAIL ~ cross section} 
The battery pack , which includes one rechargeable cell and optional circuitry , has { HEAD ~ an exterior housing } that is generally rectangular in { TAIL ~ cross section }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL