SMA America, LLC
13 Battery Management
Technical description
SI4548_6048-US-TB_en-13
113
13.4.5 Silent Mode
In addition to the float charge, the silent mode can only be used ("224.01 SilentEna" parameter)
when operating with the utility grid in the operating mode "GridCharge".
The main purpose of the silent mode is to save energy by switching from charge mode to standby
mode in 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 Island remains in silent mode for a fixed time (parameter "224.03 SilentTmMax")
or until the battery voltage per cell is 0.14 V lower than the set voltage (parameter "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.
13.5 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, "223.05 BatPro1Soc", "223.06
BatPro2Soc" and "223.07 BatPro3Soc" parameter):
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.
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" parameter.
Summary of Contents for Sunny Island 4548-US
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