Battery A claims their battery will have 80% of its original capacity at 1000 cycles to 50%
Battery B claims to have 50% of its original capacity at 1000 cycles to 50%
Look how easy that was to Skew.
Do you see the percentage of remaining capacity listed on either Concorde or Rolls' data sheets? Or How that level was determined?
Now if there was a standard, number of cycles accumulated say when 100% recharges were achieved at an initial c/5 rate at 77F and full recharge to occur within X amount of time with 14.X as a max voltage, cycled the exact same way, with no room for any variables, until 80% of original capacity was measured, then I might compare results among different manufacturers, and possibly see the data as somewhat valid to how the battery will last in actual non laboratory usage.
How do they determine 50% SOC? Specific gravity, or KWH delivered? Under what size load, what percentage of battery capacity? 20 hour rate, 25? 50?, 100?
Do you see this info listed as the test parameters anywhere by either manufacturer?
If they determine 50% by KWH delivered, do they estimate how fast 100Ah capacity declines to 99AH capacity and make the battery deliver only 49.5AH of the original 100AH for the next 50% cycle?
Do they use AH or KWH?
There are so many ways to skew testing results.
Anybody who believes marketers or marketing literature, in this day and age of 'maximum profit, baby needs a new diamond', is seriously deluded. Professional liars trained to separate one from their money, and eager lemmings waiting at cliffs edge because they got the message something was to occur.
Accumulated lab cycles likely have little to do with durability in actual use, how an Rv'er or a boater uses a battery. No one really bothers to reach 100% SOC promptly after every single recharge, and no doubt the battery in the laboratory did, It had to. And it likely did so at the charge rate which would make their battery appear to be the best. where battery A might prefer double the current compared to battery B due to denser plate paste material or stronger Acid or glass separator density, or perhaps a dozen other factors I remain ignorant of.
If 100% recharges after every cycle, then sulfation occluding the plates is likely not an issue in capacity decline, but failure, or passing below X amount of original capacity, is instead probably from plate erosion.
Not only can there be no comparison from flooded battery from manufacturer A to AGM from manufacturer B, but since we have no idea of the test parameters and what constitutes failure in the laboratory's mindset, which is then to be further massaged by the marketers so the ceo can buy his mistress a new diamond, these cycles until failure graphs are basically meaningless when compared to each other.
