Some time ago, while searching the internet for information on how to properly wire together 12V batteries in multiple banks, I stumbled upon this quite unique article by SmartGauge Electronics: How to correctly interconnect multiple batteries to form one larger bank.
The bottom line of that article is that there are commonly used ways to wire together multiple batteries in parallel, which would result in a current imbalance between them. In particular some of the batteries in a wrongly wired bank will end up providing more current to the load than the others and therefore will discharge faster. Also while being charged, some of the batteries will receive more current (and thus charge “more”) then the others, resulting in an unevenly charged bank. This imbalance between the batteries may lead to faster ageing and eventually a failure of the whole battery bank.