Battery management
SMA
Solar Technology AG
120
SI2012_2224-TEN082311
Technical Description
12 Battery management
The battery management of the Sunny Island supports the following three battery types ("221.01
BatTyp" parameter):
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 (120h, 100h, 20h, 5h,
1h) in the following manner:
The Sunny Island is designed and set by default (parameter "221.03 BatVtgNom") for a nominal
battery voltage of
•
24 V (12 cells at 2 V each) in the case of lead batteries (FLA and VRLA)
•
22.8 V (19 cells at 1.2 V each) in the case of Nickel-Cadmium batteries
12.1 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 " 221.04
BatTmpMax" parameter), a warning is displayed. If the maximal value for the battery temperature
is exceeded, the Sunny Island switches off.
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 12.4 "Charge Control" (Page 122)).
FLA
- F
looded
L
ead
A
cid:
closed lead acid batteries with liquid electrolyte in all
standard designs available on the market (grid plate,
tubular plate, small, large, etc.)
VRLA
- V
alve
R
egulated
L
ead
A
cid: Closed lead acid batteries with immobilized electrolyte
in gel or AGM (
A
bsorbent
G
lass
M
at Separator) in all
standard designs available on the market (grid plate,
tubular plate, small, large, AGM, Gel, etc.)
NiCd
- Ni
ckel-
C
a
d
mium:
Pocket-type plate or fiber plate closed nickel cadmium
batteries.
C10
C120/1.28
C10
C10
C10
C100/1.25
C10
C5/0.88
C10
C20/1.09
C10
C1/0.61
