Searay 240-1999 - battery types and issues

[Colin lighten]

hi. Had the boat for a few years, don't have decent user manual. Should the two batteries be different, I read else where that some boats have a starter and leisure batt, but I didn't know if this boat should, and which one, batt one or two?
I ask as when left switched to the batt one, overnight it often runs down with just fridge, radio and occasional water pump on. But bat 2 always starts each morning when switched to batt 2. Batt one is not a year old, but I have always had batt issues, maybe it's caused by something else, any thoughts?

 

[Little Ducky]

Does your boat battery switch have 4 positions? 1,2,Both,Off

It is a good idea to have both batteries which are tied together in one way or another be the same so they discharge at the same rate and charge at the same rate. If you have one strong battery and one weak battery tied together the life of your strong battery will be limited because it's trying to compensate for the lesser charged battery attached.