Originally Posted by sailor0516
6volt vs 12v house bank. I read 2 6volt is better than 1 12v. but would (2) 6 volt be better than 2 12v in a house bank. Cost, size, weight not withstanding. It would seem 12 v would be better if amps are same?
If you connect two batteries in series then the voltage adds up but the amp hour capacity stays the same.
Series means in line or first battery negative goes to the boat ground, positive goes to the negative of the second battery. Positive of the second battery goes to the boat system positive. OR you could say: boat ground to B1 black. B1 red to B2 black. B2 red to boat positive.
So two 225 amp hour, 6 volt batteries in series would give you 225 amp hours at 12 volts.
Two batteries in parallel the amp hours will add up but the voltage will stay the same.
So two 225 amp hour, 6 volt batteries in parallel will give you 450 amp hours but still only 6 volts.
So 12 V is not inherently better if the amps are the same. Typically two 6 volt batteries of a size equal to one larger 12 volt battery will have more amp hours. Usually cheaper, usually sturdier, certainly easier to carry around.