12V lithium-ion battery’s full charge voltage and cut-off voltage are generally as follows:

1. Full Charge Voltage
   12.6V: A 12V lithium-ion battery is composed of three cells, each with a nominal voltage of 3.7V. The maximum voltage per cell is 4.2V. When three cells are connected in series, the total voltage is 12.6V.

2. Cut-off Voltage
   9.0V: The cut-off voltage for lithium-ion batteries is typically set at 3.0V per cell. Therefore, for a 12V battery with three cells connected, the cut-off voltage is 9.0V. This protects the battery from excessive discharge.

Summary:
Full Charge Voltage: 12.6V (4.2V × 3 cells)
Cut-off Voltage: 9.0V (3.0V × 3 cells)

It is important to charge and discharge within this voltage range to ensure long battery life.