Getting fully charged on occasion is best. Maybe once every two weeks if possible. This helps keep the cells balanced and if you have a shunt it allows the shunt to recalibrate.
If you get enough sun to keep the SOC between 20% and 50% then you get enough sun to keep the SOC between 70% and 100% (assuming you can start with a full charge).
If you get enough sun to keep the SOC between 20% and 50% then you get enough sun to keep the SOC between 70% and 100% (assuming you can start with a full charge).