I have seen many people yammer about the need for all batteries in a bank to be IDENTICAL (Same age, size, make, model Bla Bla Bla)
For batteries in series,, This is true of each string.. (IE if you have a 5 cell Mag-Light flashlight you always replace all 5 batteries at the same time)
But for batteries in parallel.. You can mix and match so long as they are the same voltage and chemistry.
Mixing AGM, Flooded wet and Maintenance Free, .. Well, I have done it, with no problems but I can not recommend it (or against it)
But mixing two maintenance free (older and newer or bigger and smaller) no problem.
