Battery Management; Battery Temperature - SMA Sunny Island 5048 Installation Instructions Manual

SMA
Technologie AG

13 Battery Management

The battery management of the Sunny Island 5048 supports the following three battery
types ("#221.01 BatTyp" parameter):
FLA Flooded Lead Acid: Closed lead acid batteries with liquid electrolyte in all
standard designs available on the market (grid plate, tubular plate, small,
large, etc.)
VRLA Valve Regulated Lead Acid: Closed lead acid batteries with immobilized
electrolyte in gel or AGM (Absorbent Glass Mat Separator) in all standard
designs available on the market (grid plate, tubular plate, small, large, AGM,
Gel, etc.)
NiCd Nickel Cadmium: Pocket-type plate or fiber plate closed nickel cadmium
batteries
The battery capacity ("#221.02 NomBatCpy" parameter) is to be entered as the
nominal capacity for a ten hour discharge (C10). If this 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 5048 is designed and preset for a nominal battery voltage ("#221.03
BatVtgNom" parameter) of 48 V (24 cells for every 2 V) with lead acid batteries (FLA
and VRLA) and 45.6 V (38 cells for every 1.2 V) with nickel cadmium batteries.
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.

13.1 Battery Temperature

The Sunny Island 5048 continuously monitors the battery temperature using the
provided battery temperature sensor. A warning message is displayed once the battery
temperature drops 5 °C below the maximum permissible temperature ("221.04
BatTmpMax" parameter).
If the maximum permissible battery temperature is exceeded, the Sunny Island 5048
switches off with a fault. If the battery temperature then drops below the set limit
("#221.05 BatTmpStr" parameter), the Sunny Island 5048 restarts automatically.
When lead acid batteries drop –10 °C below the set limit and NiCd batteries drop –
20 °C below the set limit, a warning is displayed.
The battery temperature is taken into consideration when the charging voltage is
calculated (see section 13.4 "Charge Control" (Page 88)).
Technical Description
C10 C120/1.28
C10 C100/1.25
C10 C20/1.09
C10 C10
C10 C5/0.88
C10 C1/0.61
SI5048-11:EE4206
Battery Management
Page 85