Battery protection circuit, battery protection board, battery, and terminal device

A battery protection circuit, wherein the battery protection circuit comprises a connector, a power supply, a load, and a battery, the connector is electrically connected to the power supply, the power supply is electrically connected to the battery, and the battery is electrically connected to the load, wherein the battery comprises an electrochemical cell and a battery protection board, a battery protection circuit in the battery protection board comprises two input terminals, and each of the two input terminals is electrically connected to the electrochemical cell, wherein the battery protection board comprises the battery protection circuit, wherein the battery protection circuit comprises:

• a first output terminal and a second output terminal, configured to electrically connect to a power source or a load;
• a current detection element, a first switch unit, and a second switch unit, configured to connect to the electrochemical cell in series between the first output terminal and the second output terminal, so that the current detection element, the first switch unit, the second switch unit, the electrochemical cell, and the load or the power supply form a loop, to charge or discharge the electrochemical cell, wherein the current detection element comprises two terminals;
• a first detection unit, comprising a power supply terminal, a control terminal, and two detection terminals, wherein the power supply terminal of the first detection unit is electrically connected to the first output terminal, the two detection terminals of the first detection unit are electrically connected to the two terminals of the current detection element respectively, and the control terminal of the first detection unit is electrically connected to a terminal of the first switch unit;
• and
• a second detection unit, comprising a power supply terminal, a control terminal, and two detection terminals, wherein the power supply terminal of the second detection unit is electrically connected to the first output terminal, the two detection terminals of the second detection unit are electrically connected to the two terminals of the current detection element respectively, and the control terminal of the second detection unit is electrically connected to a terminal of the second switch unit.