Battery charge and discharge system

The invention provides a battery charge and discharge system which is provided with a control unit, a constant current unit, a constant voltage unit, a selection unit, a charge and discharge unit andan early warning unit. In the actual application process, when a battery is in an abnormal state during the charging and discharging process, the control unit outputs a level signal to the charge anddischarge unit, and the charge and discharge unit stops working to stop battery charging and discharging to prevent the battery from working in the abnormal state and being damaged. The arranged earlywarning unit can promptly feed back the abnormity of the battery to a user to enable the user to quickly take relevant abnormal measures to prevent the battery from being damaged due to the abnormalstate. Furthermore, the constant current unit and the constant voltage unit can enable the battery to complete the charging and discharging process at a constant current or constant voltage state, soas to ensure the work stabili