determining the capacity of the rechargeable battery when {TAIL ~ the discharge level} at which {HEAD ~ the capacity} of the rechargeable battery can be learned is reached 
at
determining the capacity of the rechargeable battery when { TAIL ~ the discharge level } at which { HEAD ~ the capacity } of the rechargeable battery can be learned is reached
OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL REL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH