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command during emergency charge. The following tables describe the emergency charge
conditions for different types of batteries.
table 3-3 Backup Charge Management for Li-ion Battery
Status Conditions
Trigger
Either of the following conditions is met:
• SOC ≤ (Min. SOC) – 3% (valid only when the Min. SOC is ≥ 3 %).
• A battery under-voltage warning is triggered.
• An emergency charge command is reported to the inverter.
Finish
All the following conditions are met:
• SOC ≥ (Min. SOC) – 1% (valid only when the Min. SOC is ≥ 3 %).
• The battery under-voltage warning is cleared.
• The emergency charge command reported to the inverter is cleared.
table 3-4 Default SOC Conditions for Li-ion Battery Backup Charge
Type Trigger SOC Finishing SOC
SUNGROW SOC ≤ 2 % SOC ≥ 4 %
BYD (Battery-Box Premium HVM /
HVS)
SOC ≤ 2 % SOC ≥ 4 %
Normal Charge Management
When the battery voltage is within the normal range, the inverter can charge the battery if
the PV power is higher than the load power and can ensure that the battery is never over-
charged.
The maximum allowable charge current is limited to the smaller value among the following:
• the maximum charge current of the inverter (50A);
• the maximum / recommended charge current from the battery manufacturer.
For this reason, the battery charge power may not reach the nominal power.
• If the PV voltage is higher than 950 V, the battery cannot charge.
• The hybrid inverter will start to charge the battery when the export power value
exceeds a pre-defined threshold value of 70 W.
3.3.2 Discharge Management
Discharge management can effectively protect the battery from deep discharging.
The maximum allowable discharge current is limited to the smaller value among the
following:
• the maximum discharge current of the inverter ;
User Manual 3 Function Description