Disclosed is a device carrying out whole-course, real-time and comprehensive monitoring, such as parameter detection, analysis, learning, control, display, external communication and the like, for the charging-discharging process of a lithium battery pack, namely an intelligent management system for power lithium batteries, which mainly comprises a voltage detection device, a current detection device for detecting electric current in the process of charging and discharging of the lithium battery pack, a temperature detection device, a control device, a charging-discharging state judgment device, a computing device, a data storage device, a parameter correction device, an automatic learning device, a data display device, a communication device, a protection device, a system automatic diagnosis device and an alarm display device. Further disclosed is a device (instrument) for detecting the performance of the lithium battery, which mainly comprises a voltage detection device, a current detection device, a temperature detection device, a control device, a computing device, a data storage device, a parameter correction device, a residual capacity judgment device, a data display device, a communication device, a protection device, a system automatic diagnosis device and an alarm display device.