While I know the most effective determination of battery health is something like a CBAIV, the Battery Beak is accepted as a very good way to check on a battery when you can't discharge it.
Given the data from a Beak, how do you determine the ideal next battery? State of charge? Internal resistance? V0/V1/V2? Any attempt to balance out match cycles?
This thread had a lot of good information, but not quite
that information.