Patent attributes
This application provides a battery protection circuit, a battery protection board, a battery, and a terminal device. The battery protection circuit includes: a first detection unit; a second detection unit; and a current detection element, a first switch unit, and a second switch unit that are configured to connect to an electrochemical cell in series, to form a charging loop or a discharging loop. The first detection unit corresponds to the first switch unit, and the second detection unit corresponds to the second switch unit. Each detection unit controls, based on a detected voltage at two ends of the same current detection element, a corresponding switch unit to be closed or opened, so as to control the loop to be closed or opened. The first detection unit and the second detection unit detect the voltage at the two ends of the same current detection element to detect a current passing through the electrochemical cell, so that a quantity of current detection elements in the battery protection circuit can be effectively reduced, to reduce impedance of the battery protection circuit.