just got a new van, has a 185A smart alternator and 92A AGM battery. I want to replace that battery with twin 105A AGM batteries but there are 2 schools of thought on this. one idea is to have both batteries identical in every way including age and wire them in parallel but some people say this introduces extra resistance which the smart alternator won't like. the other way is to get a dc to dc charger installed between the batteries. if i go down the 2nd route what size charger do i need if my 3 power amps draw 100A from the 2nd battery
