SMA SI 5048, Техническое описание

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Battery management SMA Solar Technology AG
92 SI5048-TEN093630 Technical Description
13 Battery management
The battery management of the Sunny Island supports the following three battery types
("221.01 BatTyp" parameter):
• FLA
• VRLA
• NiCd
The battery capacity ("221.02 BatCpyNom" parameter) is to be entered as the nominal capacity for
a ten-hour discharge (C10). If this information is not available from the battery manufacturer's data
sheet, it can be calculated from the data for different discharge times (120 h, 100 h, 20 h, 5 h, 1 h)
in the following manner:
The Sunny Island is designed and set by default (parameter "221.03 BatVtgNom") for a nominal
battery voltage:
• 48 V (24 cells at 2 V each) in the case of lead batteries (FLA and VRLA)
• 45.6 V (38 cells at 1.2 V each) in the case of Nickel-Cadmium batteries
13.1 Battery temperature
The Sunny Island continuously monitors the battery temperature using the battery temperature sensor
provided. At 5°C under the maximal temperature allowed (set using the parameter "221.04
BatTmpMax"), a warning is displayed. If the maximal value for the battery temperature is exceeded,
the Sunny Island switches off.
When lead acid batteries drop below − 10 °C and NiCd batteries drop below − 20 °C, a warning
is displayed.
The battery temperature is taken into consideration when the charging voltage is calculated
(see section 13.4 ”Charge control” (page 94)).
C10 C120/1.28 C10 C10
C10 C100/1.25 C10 C5/0.88
C10 C20/1.09 C10 C1/0.61
Malfunction of individual battery cells
If individual battery cells fail over several years of continuous operation, the nominal
voltage can be set in the range from 42 V to 48 V. Up to three individual cells can be
removed and the system can still be further operated.