The invention relates to the technical field of battery maintenance, and in particular to an on-line pulse activation device and system for a single battery. The device comprises a central processingunit and a charging and discharging module, wherein the central processing unit is connected to the charging and discharging module; the charging and discharging module is respectively connected to anexternal power source and the single battery; the central processing unit is used for acquiring characteristic parameters of the single battery in real time through the charging and discharging module, entering a corresponding mode according to the characteristic parameters and a preset mode switching mechanism, sending a control command corresponding to the mode thereof to the charging and discharging module in the mode in which the central processing unit enters, and controlling the charging and discharging module to perform an operation corresponding to the control command. By using the device provided by the invention, the detection of each single battery in the battery pack can be realized, and the individual management and maintenance of each single battery can be carried out according to the detection result of each single battery.