In recent years it has been confirmed that you generally do not want to use a float charge when charging Lithium Iron Phosphate (LiFePO4) batteries. Unlike lead-acid batteries, which benefit from a float charge to maintain capacity, LFP batteries do not tolerate float charging well and it can actually shorten their lifespan. Instead, once an LFP battery reaches full charge, the charging current should be completely turned off.
To this end, REC has updated their firmware, beginning around 2.9x, to allow the sytem to fully charge, the drop a few percent, then charge again. There is a new parameter that allows you to tune this function.
It also means your remote Victron or other system status may no longer go into "Float mode"
Here is an exerpt from the 2Q 2.9.X manual that goes into some detail on it.
Maximum Cell Float Voltage Coefficient (CFVC) has been introduced into the charging
algorithm to enable cell float voltage change after the full charge. It may be set from
0.0 to 1.0 of the End of Charge Hysteresis CHIS. When End of Charge Hysteresis CHIS
and End of Charge SOC hysteresis SOCH have been met, full charge is enabled again.
@ CFVC 50 % of maximum charging current is allowed to supply DC loads from
MPPTs directly without discharging the battery pack below End of Charge Hysteresis
CHIS and End of Charge SOC hysteresis SOCH. If CFVC is set to 0.0, charging current
is set to 0.0 A until the End of Charge Hysteresis CHIS and End of Charge SOC
hysteresis SOCH have been met
