SMA SUNNY ISLAND 4.4M Operating Manual page 73

SMA Solar Technology AG
• Systems for increasing self-consumption that are not intended to feed in any excess PV energy (zero feed-in
systems) and therefore switch off the PV system by means of a contactor before the battery state of charge
reaches 100% SOC (see planning guidelines "PV systems with zero export"). Here, the source of equalization
charge is the utility grid.
• Off-grid systems powered by a PV inverter and a generator as an external energy source. Due to seasonal
fluctuations, a battery state of charge of >95% may not always be achieved. Here the source of equalization
charge is the external energy source (e.g. diesel generator).
•
To activate the equalization charge for lithium batteries, there are the following possibilities:
• Set manual equalization charge.
• Set automatic equalization charge.
Set manual equalization charge
The manual equalization charge performs the procedure only once. A started equalization charge can be terminated
via Stop.
Procedure:
1. Select Battery > Battery > Operation.
2. Click the On button to activate Manual equalization charge.
3. Click the Off button to deactivate Manual equalization charge.
Set automatic equalization charge
Display of irrelevant parameters
When connecting lithium-ion, some parameters are displayed in the Battery > Charge menu that are not relevant
for automatic equalization charge and cannot be set:
• Time for boost charge Time for equalization charge / Time for full charge Cut-off voltage
• Cell charge nominal voltage for boost charge / Cell charge nominal voltage for full charge / Cell
charge nominal voltage for equalization charge / Cell charge nominal voltage for trickle charge
• Full charge cycle time Temperature compensation
• Setpoint of the battery charging voltage with disabled battery management system
Parameter
Automatic equalization charge
Time until equalization charge has been com-
pleted in SOC range 1
Time until equalization charge has been com-
pleted in SOC range 2
Operating manual
Explanation
If automatic equalization charge mode is set to On, the Sunny Island
automatically starts and stops equalization charge within the limits of
the set values. The value Off stops the automatic equalization charge
mode. These selections apply to both lead-acid and lithium-ion batter-
ies.
Fixed SOC ranges are assigned to these 2 parameters:
• SOC range 1: 0% to 95%
• SOC range 2: 96% to 100%
When the respective SOC range is reached, monitoring of the re-
spective set time period begins. After the respective time set for 1 of
the 2 SOC ranges has elapsed, the equalization charge is consid-
ered to be completed and the battery discharge is released again.
7 Commissioning
SI44M-80H-13-BE-en-15 73