acually a new battery isnt totaly neccacary... i got a lightning audio deep cycle/ started battery........ my car wqas having electrical problems so it drained...... so then i put a reugular battery in they lasted about the same some people prefer acid batteries in cold areas cause they say they dont take as long to charge so there better in the cold........ so if u get a new alt it isnt totaly neccacary to get a new battery illl test both after i get my car back with a 150a alternator