Sunny Island
Installation & Operating Instructions
BWRI33-12:EE
- 112 -
SMA Regelsysteme GmbH
180 days or 30 charge throughputs
U > 2.45V for 5 h
U > 2.4V for 10 h
V > 2.5 V for 1 h
SOC 70%
Float charge
U = 2.23 V
Normal charge
U = 2.55 V
Full charge
U = 2.5 V
Equalizing charge
U = 2.45 V
180 days or 30 charge throughputs
14 days or 8 charge throughputs
Fig. 11.1: Battery states with charging methods
The specified values are default values for a closed not circulated lead-acid battery.
A normal charge is made when the charging degree has fallen below 70 %. The pri-
ority is a short run-time of an additional aggregate (e. g. diesel generator).
By default, a full charge is completed every two weeks or 8 charge throughputs. A
full charge leads to complete charging of the battery in order to avoid irreversible ag-
ing due to low charge degrees.
An equalizing charge is initiated every 180 days or 30 charge throughputs preventing
that the individual cells within the entire battery system over time have charge de-
grees differing among each other and avoiding aging of individual cells.
The respective charges are switched off according to the criteria for voltage, current
and time periods adjusted to the individual battery types.
11.2 Battery States
The battery management determines the state of the battery out of a selection of
eleven possible battery states. It informs the relay control about the determined bat-
