A solar battery is a kind of battery that can be charged by either solar energy or regular inverter and can store energy for  later  use as per the user’s need. The energy stored in it can be used whenever one wants only in an off-grid solar system, especially if a power-cut takes place.

DC-coupled solar system:

• During the day, solar panels convert sunlight into DC electricity.
• The electricity is then stored in the battery as DC electricity.
• When required, the DC electricity leaves the solar battery and enters an inverter which converts it into AC electricity that can be used by appliances in the home.

AC-coupled solar system:

• During the day, solar panels convert sunlight into DC electricity.
• The electricity then enters the inverter and is converted into AC electricity to be used in the home.
• Surplus energy then flows through another inverter to convert back into DC electricity which can be stored in the battery.
• If the energy stored in the battery needs to be used in the home at a later point, such as at night, then it must convert back to AC electricity again through the inverter.