SMA Sunny Island 5048 Installation Instructions Manual page 87

SMA
Technologie AG Battery Management
The estimated charge state error (display value "#120.11 BatSocErr") will provide you
with continuous information on the accuracy of the battery charge state currently
calculated. The average error will continuously diminish as the adjustment to the actual
battery increasingly improves.
Only when the battery is new does its usable capacity correspond to the capacity
specified by the battery manufacturer. As the battery ages and as a result of frequent
insufficient charging, the battery's useable capacity may decrease considerably on a
permanent or only a temporary basis. The battery's state of health (display value
"#342.01 Soh") is a percentage measurement for the current useable capacity relative
to the nominal capacity. 100 % means that the entire nominal capacity can still be
utilized. At 50 %, only half of the original nominal battery capacity can be utilized. A
self-adapting method, which takes between 4 and 8 weeks to produce good and exact
values, is also used to calculate the battery's state of health.
The current capacity for the Sunny Island 5048 is automatically adjusted downwards
for temperatures <20 °C, since the useful capacity of batteries is significantly reduced
in temperatures below the nominal temperature. For all lead acid batteries, the nominal
capacity is amended by a fixed factor of –1 %/°C. For NiCd batteries a factor of –
0.75 %/°C is used.
Technical Description SI5048-11:EE4206 Page 87