8
5. Storage
The battery voltage is maintained at the configured storage voltage, which is slightly reduced
compared to the float voltage to minimise gassing and extend battery life whilst the battery is
unused and on continuous charge.
6. Refresh
To refresh the battery and prevent slow self-discharge while in storage stage over an extended
period, a 1 hour absorption charge will automatically occur every 7 days (or as configured).
3.2 Temperature compensation
The Victron
Blue Smart Charger
range will automatically compensate the configured charge
voltage based on ambient temperature (unless disabled or in Li-ion mode).
The optimal charge voltage of a lead acid battery varies inversely with battery temperature;
automatic temperature-based charge voltage compensation avoids the need for special charge
voltage settings in hot or cold environments.
During power up the charger will measure its internal temperature and use that temperature as
the reference for temperature compensation, however the initial temperature measurement is
limited to 25°C as it’s unknown if the charger is still warm from earlier operation.
Since the charger generates some heat during operation, the internal temperature
measurement is only used dynamically if the internal temperature measurement is considered
reliable; when the charge current has decreased to a low/negligible level and adequate time has
elapsed for the charger’s temperature to stabilise.
The configured charge voltage is related to a nominal temperature of 25°C and linear
temperature compensation occurs between the limits of 6°C and 50°C based on the default
temperature compensation coefficient of 16.2mV/°C (for 24V chargers multiply the coefficient by
2) or as configured.
The temperature compensation coefficient is specified in mV/°C and applies to the entire
battery/battery bank (not per battery cell).
