Charge Control; Charging Phases - SMA SUNNY ISLAND 8.0H Installation Manual

SMA Solar Technology AG
If the maximum permitted battery temperature is exceeded, the off-grid inverter switches off. Once the
battery has cooled down to a specified temperature, the off-grid inverter starts again.
9.2 Charge Control
9.2.1 Charging Phases
Figure 29: Charging phases of the off-grid inverter
The off-grid inverter controls battery charging in three phases, as follows:
• Constant current phase (I phase/bulk phase)
• Constant voltage phase (absorption phase/Uo)
• Float charge
There is also the idle phase in the case of electricity grid operation with activated silent mode.
Constant Current Phase
The aim of the constant voltage phase is to reach the full battery voltage.
In the constant current phase, battery management initially increases the current until one of the
following values has been reached:
• Maximum charge current of battery
• Rated current of the external energy source
• Maximum AC charge current of the off-grid inverter
Installation Manual
9 Battery Management
SI80H-60H-OffGrid-IA-en-11 125