Battery-operated portable electronics, from smartphones to notebook computers, are generally sold with a dedicated power supply. The power supply operates the device and also charges the built-in battery. Most users are concerned about the battery aging while the device is operated by the built-in battery. This is the first paper to our knowledge that discovers, analyzes and mitigates the built-in battery aging when the device is operated with the provided power supply. We focus on the fact that in an effort to reduce size and weight, the capacity of the power supply is optimized for the average power demand rather than the maximum power demand. Such a reduced-capacity power supply brings advantages in terms of size, weight and cost but it accelerates the battery aging because the aging progresses even when the device is operated by the power supply, which is different from the expectation of most users. We quantitatively analyze such battery aging with various operating scenarios based on standard benchmark programs. We show that the battery experiences significant aging, i.e., the battery lifetime can be reduced to 23% of its shelf lifetime. Finally, we propose a cost-effective supercapacior hybrid to mitigate such battery aging when the device is operated using the power supply. The simulation results show that 10, 1 and 0.1 mF supercapacitors can reduce the battery aging by 68.6%, 55.1% and 4.6%, respectively.

Related Papers

[C-14-05] Jaemin Kim, Alma Pröbstl, Samarjit Chakraborty and Naehyuck Chang, "Aging Mitigation of Power Supply-Connected Batteries," in IEEE/ACM International Symposium on Low Power Electronics and Design (ISLPED), 2014.  [PDF]