SMA
Solar Technology AG
Battery management
Technical Description
SI2012_2224-TEN082311
127
12.4.4 Manual Equalization Charge
The parameter "520.01 ManChrgSel" activates the manual equalization charge on the Sunny
Island. If a generator is connected to the system, it will be automatically started, and stopped again
after the equalization charge is completed.
12.4.5 Silent Mode
In addition to the float charge, the silent mode can be used ("224.01 SilentEna" parameter), only
when operating on the public grid.
The main purpose of the silent mode is to save energy by switching from charge mode to standby
mode in utility backup systems where the Sunny Island is predominantly in float charge.
The silent mode is activated after the time set for float charge ("224.02 SilentTmFlo" parameter) has
expired. The Sunny Backup system remains in silent mode for a fixed time ("224.03 SilentTmMax"
parameter) or until the battery voltage per cell is 0.14 V lower than the set voltage ("222.10
ChrgVtgFlo" parameter). This ensures that the battery is always fully charged, even in silent mode.
If a grid outage is detected during silent mode, the Sunny Island makes a stand-alone grid available
within a few milliseconds. The loads are supplied with power almost without interruption.
12.5 Battery Preservation Mode
The Sunny Island has a sophisticated battery preservation mode. The battery preservation mode
prevents, as far as possible, the battery from being deeply discharged when the energy supply is
low, preventing a total system failure as well as damage to the battery.
The battery preservation mode has three levels that are activated as a result of the state of charge
(when the charge drops below the respective limit, parameters "223.05 BatPro1Soc", "223.06
BatPro2Soc" and "223.07 BatPro3Soc"):
Level 1:
The first level is used to switch the Sunny Island into standby mode at times when the
energy is not necessarily required (e.g., at night). You define the start time using the "223.01
BatPro1TmStr" parameter and the stop time using the "223.02 BatPro1TmStp" parameter.
Information
An equalization charge should be performed at least once a year. After a long period of
time without charging, e. g., in the case of systems which are only operated seasonally,
manual equalization charges are required at the end or at the beginning of the season.
