Abstract: A battery pack includes a battery housing and a battery cell. The battery housing includes a first wall and a first protruding portion that protrudes beyond an inner surface of the first wall. The first protruding portion and the first wall form a first recessed portion. The battery cell is accommodated in the battery housing. A pressure relief mechanism is disposed at one end, oriented toward the first wall, of the battery cell along a first direction. The end, oriented toward the first wall, of the battery cell is connected to the first protruding portion. Along the first direction, a projection of the pressure relief mechanism is located within a projection of the first recessed portion. Through the above structure, the first protruding portion and the first wall can separate the pressure relief mechanism of one battery cell from that of other battery cells.

Abstract: A method for detecting an internal resistance of a secondary battery, and an electronic device. The method for detecting an internal resistance of a secondary battery includes: charging a secondary battery with a charge current, and in response to a real-time state of charge (SOC) of the secondary battery reaching a target SOC value, stopping charging the secondary battery and keeping for a first duration t; and obtaining data related to the secondary battery during a charge period and a charge stopping period of the secondary battery, and determining the internal resistance of the secondary battery on the basis of the data related to the secondary battery, where the target SOC value includes a plurality of values.