Calibration Charging For The Fronius Solar Battery; Benefits Of Calibration Charging; General; Conditions For The Start Of Calibration Charging (Fronius Solar Battery) - Fronius Symo Hybrid 3.0-3-S Operating Instructions Manual

Calibration charging for the Fronius Solar Battery

Benefits of calib- Natural differences in the individual cell capacities and the small amount of self dis-
ration charging charge that occurs in all batteries cause the cell voltages to diverge. This makes the
SOC value less accurate, which affects the operation. If no steps are taken, the battery
will become damaged.
Periodic calibration charging brings all cells of the battery to the same state of charge,
and calibrates the SOC value. This ensures a longer service life of the battery cells.

General

Determining the exact state of charge (SOC) of the battery is important for operation
management. To ensure this happens, the battery must regularly be charged to 100%.
This allows the SOC value to be calibrated.
Fronius Solar Battery:
Calibration charging occurs automatically during operation after several charge and dis-
charge cycles. When calibration charging is carried out depends on two crucial factors:
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As these factors are extremely weather dependent, the time of a calibration charge can
vary depending on the time of year.
The following description of calibration charging is valid from version 1.4.1-12 of the
Fronius system monitoring software.
Conditions for One charge and discharge cycle of the Fronius Solar Battery corresponds to an energy
the start of calib- throughput of 48 Ah per battery module. Calibration charging occurs cyclically according
ration charging to the following conditions:
(Fronius Solar -
Battery) -
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For newly installed systems and for module replacement or expansion, a calibration
charge is started automatically after 30 minutes.
Calibration char- Calibration charging primarily occurs with the entire PV power. If insufficient PV energy is
ging procedure available, energy is drawn from the public grid. This is also the case even if the "Battery
(Fronius Solar charging from DNO grid" function is deactivated, as this is a critical requirement.
Battery)
The SOC is calculated per battery module. For this reason, each battery module must
reach a SOC of 100%.
Average state of charge
Energy throughput of the battery
After half a charge and discharge cycle and a SOC of approx. 97%
After 3 full charge and discharge cycles and a SOC of 80%
After 5 full charge and discharge cycles and a SOC of 50%
After 7 full charge and discharge cycles, independent of the SOC
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