Victron VE.Bus Configuration Guide

10.4.3. Float voltage
Use this setting to specify the Float voltage. Float stage is reduced voltage from absorption, used to trickle in current to finish
battery charge without creating excess heat or gassing.
10.4.4. Absorption voltage
Use this setting to specify the Absorption voltage. Absorption is the charge phase where the battery is held at continuous target
voltage with variable current.
10.4.5. Repeated absorption interval
Use this setting to specify the interval between repeated absorptions.
10.4.6. Repeated absorption time
Specify the duration of the repeated absorption "pulses".
10.4.7. Maximum absorption time
If the charge curve is fixed then this setting is used to determine the absorption time. In all other cases this setting determines the
maximum absorption time.
10.4.8. Charge curve
Under normal circumstances always select the adaptive mode. If the balance between the charger and battery is not ideal, it may
be better to choose fixed mode otherwise the voltage will rise too quickly or too slowly and the battery may be over or under
charged as a result.
10.4.9. BatterySafe
BatterySafe curve has a special regulation in the absorption phase. The absorption phase will start when the voltage reaches
14.4V (for a 12V battery) regardless of the specified absorption voltage. During the absorption phase the voltage will increase
with a fixed ramp until the voltage reaches the absorption voltage or until the calculated absorption time is over. In the latter case
the absorption phase will end before the absorption voltage is reached.
In a lead acid battery the charge process isn't always perfectly spread throughout the battery so therefore it can happen that when
charging fast (at the limit of what the battery can handle voltage wise), a part of the battery is already "charged" while other parts
still have the ability to absorb energy. When the charger is going "full power" to the setpoint voltage to enter absorption the
change is quite realistic that a part of the battery is getting overcharged.
BatterySafe reduces the charge current when the voltage is approaching the setpoint to enter absorption. Therefore the battery
gets a longer lifetime.
Same as for Adaptive (when the absorption period is calculated from the time the charger is in the Bulk phase), it helps extend
the lifespan of the battery.
In general, beware that the wish to charge "as fast as possible" often results in a shorter lifespan of the (lead acid) battery. Taking
it a bit slower will indeed cost fuel/time but will pay itself back in battery lifetime. Charging the battery with the generator is most
efficient in the 50-80% SOC range. So have this done daily and only go to 100% weekly as then the battery monitor is synced and
the battery gets a needed full charge.
10.4.10. Lithium battery mode
Checkbox function
The table below shows the effect of Enabling or Disabling Lithium battery mode:
Feature Lithium mode Disabled (default) Lithium mode Enabled
Temperature
compensation
Lead algorithm No temperature compensation
Re-bulk voltage 1.3V less than Float-voltage, to a
maximum of 12.9V
0.2V less than Float-voltage, to a maximum of
13.5V
Note: All mentioned voltages and thresholds are for a 12V system. For 24 multiply by two; and for 48V, multiply by four. So for
example at 48V, the re-bulk mechanism for a lithium battery will use Vfloat - 0.8V with a maximum of 54V.
Temperature compensation Charge voltage are not increased or decreased within normal temperature ranges (5°C - 40°C) for
lithium batteries. Enabling Lithium mode will disable the normal built-in temperature compensation features that are used for lead
acid batteries.
VictronConnect - VE.Bus Configuration guide
Page 15 Description of Settings