SMA Sunny Island 5048 Installation Instructions Manual page 89

SMA
Technologie AG
charging processes
I-Phase
1
Boost Charge
(U Phase)
0
4
Float Charge
(U Phase)
6
Silent Mode
(Ruhephase)
Once this constant voltage phase is finished, the Sunny Island 5048 switches to float
charge which again carries out constant voltage charging but at a greatly reduced
charging voltage ("#222.10 ChrgVtgFlo" parameter). The purpose of the float charge
is to keep the battery in a fully charged state without causing premature aging through
overcharging. The Sunny Island 5048 remains in this phase until either more than 30 %
of the nominal capacity (all discharges are added together) has been used or the
charge state is less than 70 %. When the Sunny Island 5048 is operating on the public
grid, it can also switch from the float charge into silent mode (see section 13.4.5 "Silent
Mode" (Page 91)).
The charging voltage does not rapidly change, but is slowly adjusted to the new
nominal value by approx. 0.5 mV/cell*s as the constant voltage phase changes
to the float charge. This also takes place if the nominal value is changed manually.
The charging capability of batteries is heavily dependent on the battery temperature.
For temperatures <20 °C, the charging voltage must be slightly increased, and for
temperatures >20 °C it must be slightly decreased. This is necessary to reliably prevent
overcharging and insufficient charging at all battery temperatures. For this reason, the
Sunny Island 5048 is equipped with automatic temperature compensation of the
charging voltage. The charging voltage is adjusted by 4 mV/°C and cell for battery
Technical Description
3
Full Charge
(U
5 4
7
2
2
Phase)
0
Legend:
1: after reaching
2: after Zeit CycTmEqu (#225.05)
3: after Zeit CycTmFul (#225.04)
4: if AptTmRmg = 0 (#120.04)
5: if SOC < 70 % (#120.01)
6: only in utility, if SilentTmFlo is up (#224.02)
7: only in utility, if SilentTmMax is up (#224.03)
SI5048-11:EE4206
Battery Management
Manual
Equalization Charge
(U Phase)
0
4
Page 89