Setting the “Charged voltage“ based on float voltage causes many systems to falsely synchronize early. I believe this recommendation by Victron is based on the assumption of a shore based charging system. They do address this issue in the troubleshooting section of the manual.
“10.3.11. Synchronisation issues
…
It is also possible that the battery monitor synchronises too early. This can happen in solar systems or in systems that have fluctuating charge currents. If this is the case change the following settings:
- Increase the “charged voltage" to slightly below the absorption charge voltage. For example: 14.2V in case of 14.4V absorption voltage (for a 12V battery).
- Increase the “charged detection time” and/or decrease the "tail current" to prevent an early reset due to passing clouds.”
Follow the FB groups for Solar on a Boat, or Lithium Batteries on a Boat, or the Victron Energy Users and you will see nearly weekly posts of someone complaining that their batteries are dead in the morning but the BMV/SmartShunt was showing 100% at sunset.