Battery-Preservation Mode - SMA SUNNY ISLAND 4548-US Operating Manual

SMA Solar Technology America LLC 13 Battery Management
"222.10 ChrgVtgFlo"). This ensures that the battery is always fully charged, even in silent mode. If a
grid failure is detected during silent mode, the Sunny Island makes a stand-alone grid available within
10 ms to 30 ms.

13.6 Battery-Preservation Mode

The Sunny Island has a sophisticated battery-preservation mode. The battery-preservation mode
prevents deep discharge from the battery as far as possible when the energy supply is low, thus
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 battery state of
charge (when the charge falls 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 parameter
"223.01 BatPro1TmStr" and the stop time using the parameter "223.02 BatPro1TmStp".
Level 2: The second level of the battery-preservation mode ensures that the Sunny Island is started
regularly every two hours only in the time period during which energy supply is expected, and that it
attempts to charge the battery from the AC side. For PV plants, this is during the day. In this case, you
define the start time using the parameter "223.03 BatPro2TmStr" and the stop time using the
parameter "223.04 BatPro2TmStp".
Level 3: The third level ensures that the battery is protected from deep discharge and thus protected
against damage. In this case, the Sunny Island is switched off completely.
• To recommission the Sunny Island, restart it (see Section 9.5 "Recommissioning After Automatic
Shutdown", page 77).
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