a 'dead battery' = ('Brit') a 'flat battery' [=a battery that has no more electricity]
The operation was performed by a 'battery' of doctors.
He was found guilty of 'battery'.
(..) ...but there's a bonus involved. Tax-free. We can't conceal that you were a trainee. You'll be convicted of a crime. We're thinking a guilty plea to assault and battery would make sense. Given your nature. You'll do enough jail time to convince anyone this is no setup. You'll be on probation, (..)2006 The Departed