Mixing batteries of different ages
I know that it’s not optimal, but how important is it to not mix batteries of different ages in an interconnected bank? I’m aware of the “lowest common denominator” line of thought, but wonder how much practical wiggle room exists. Here’s the deal:
I intend to eventually have 8 golf cart batteries (full-time off grid), with 4-600 watts of solar. Finances are such that I can’t just now pop for the whole deal, and the filthy lucre situation is not likely to drastically improve. Probably I’ll start out with one or two panels and two batteries, and add capacity as cash allows. I hate the thought of getting a pair of throwaway batteries just to replace them with four, and again with eight when I can finally afford the full setup.
So, if I tried to start with two of the batteries I want, then add more later, would I be seriously screwing the pooch, or just sliding by in somewhat sub-optimal bliss (which is my general lifestyle anyhow)? Alternately; I suppose I could get a couple of cheap-ish 12-volt deep-cycles now and later use them for something else like reserve capacity for the old Jeep, but that would stretch-out the timeline on getting to where I want to be and add more stuff to a life striving for the opposite.
All thoughts, love letters, hate mail and brain farts welcome.
It's not the heat, it's the stupidity.