Converter charging vehicle battery

You do not want to charge both your house batteris and you vehicle batteries at the same time using your converter, you also do you want to charge your dual house batteries if you have them for two reasons. first if one battery is weaker than the other one the converter does not know how to just charge one of them so you will cook (over charge one battery)one battery ruining it while chargeing the other one. The other reason is if one battery is bad and it is connected in any way with the other battery it will cause the other battery to go bad. Never charge both batteries at the same time, I installed a disconnect to both of my batteries I turn one off and charge the other on when its charged I than shut that one off and turn on the other one to charge it. Hope this helps I found this out the hard way after replacing three sets of batteris in a year and a half.