A few disclaimers firstly:
I appreciate that SoC is not an exact science, depends a lot on chemistry and settings.
I have also ensured that the settings are such that the SoC doesn't switch to 100% too early
I have a 560aH flooded lead acid batteries (less than 6 months old) with 3 X MPPTs, SmartShunt and a Multiplus.
So heres my question:
I have read a number of Victron litterateur that absorption should start when the batteries are about 85-90% full. Where as on my SmartShunt, the SoC is often at 97-99% when Absorption starts. To put it into context, my usage is such that when my solar chargers start in the morning, I have used about 75aH overnight which is approximately 15% of capacity (again, I know there's no way of know that without testing). My SoC reads 87%. Perfect, about what you'd expect. The batteries are then charged during the day at about 7amps per hour for 10 hours. They then switch to absorption for the last 3 hours when SoC is is about 98% and go to float after 3 hours absorption. (3 hours absorption based on adaptive charging on my MPPTs).
So based on the above, I would assume that the SoC is working as expected, and my interpretation of "SoC=90% when absorption starts" is incorrect? Any ideas?