Re: Mixing Old and New batteries
I agree with both Bill and Telco.
Either run the string short 'till they all croak, or buy a couple of of cheap batteries that combine equal one or more of you originals and hope for the best.
In one installation, I am running 3 l-16's that are ten years old, with 2 t-105's seriesed so that I essentially have 4 batteries in the string, but one battery is the 2 t-105s' (Their combined ah capacity is roughly similar to the L-16's). They are also better than ten years old.
Please note, being a moderator does not add any weight to my opinions 300 watts Siemens/BP panels,plus a Sun 90,, making ~400. ~30 amps into Rogue MPT-3024, 450 ah of Trojan T-105, Morningstar ts300 inverter, a Tri-Metric meter.a collection of antique generators, plus 2 Honda eu-1000i's (also a BS2512 IX controller) and assorted other stuff!