Higher inner stress than the strength of the shell is one of the main problems for the safety of batteries. In order to improve the safety management of batteries, a non-destructive method has been adopted to real-time monitor the stress level of the NCM batteries during charging/discharging process. Besides, the relationship between strain and stress for the coin cell has been analysed. During cycling process, the stress level has the same trend with the potential value, and residual stress has been found at the end of every cycle. In order to investigate the relationship between the stress accumulation and the electrochemical performance of the cells, the residual stresses and the normalized capacities of NCM cells under different current densities have been monitored.
Most existing data backup systems are too professional to understand. It usually needs time-consuming training for a man to learn how to configure the backup system to make sure it works well. This has greatly affected the data backup systems popularity. In this paper, we design and implement an embedded backup system which uses a hard disk and an embedded development board to integrate a backup-server and a backup-client, increment backup in non-fixed block-level, and provides a friendly Web UI (user interface) to the end-user. The final evaluation shows that the system is easily, efficiency, storage-space saving and network-bandwidth saving, and it can be used in many situations.