That's all well and good ... but, but, ... if one was to read the Megger article in the link I provided, then it would become obvious that if one could only figure out how to measure battery impedance over time so as to watch it increase with battery age, then one should be able to see the high impedance target point that essentially means "replace me".
I guess it must be that measuring lead acid battery impedance while the battery is still in the RV is too difficult to pull off ... but with lithium batteries in a vehicle there's other ways to estimate their end of life ahead of time?
I guess I'll have to read the owner's manual for my daughter's new Honda hybrid to learn what dash light comes on 10 years from now indicating it's battery funeral time.
P.S. Another goal of mine is to not ever have to use a hydrometer cuz my RV batteries don't have a hole for one.
